Na}{

Path: ~//opt/alt/postgresql11/usr/share/doc/alt-postgresql11-9.2.24/html/

File Content: xfunc-c.html

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>C-Language Functions</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.2.24 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="Extending SQL"
HREF="extend.html"><LINK
REL="PREVIOUS"
TITLE="Internal Functions"
HREF="xfunc-internal.html"><LINK
REL="NEXT"
TITLE="User-defined Aggregates"
HREF="xaggr.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2017-11-06T22:43:11"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.2.24 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="Internal Functions"
HREF="xfunc-internal.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="extend.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Chapter 35. Extending <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
></TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="User-defined Aggregates"
HREF="xaggr.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="XFUNC-C"
>35.9. C-Language Functions</A
></H1
> User-defined functions can be written in C (or a language that can
 be made compatible with C, such as C++). Such functions are
 compiled into dynamically loadable objects (also called shared
 libraries) and are loaded by the server on demand. The dynamic
 loading feature is what distinguishes "C language" functions
 from "internal" functions &mdash; the actual coding conventions
 are essentially the same for both. (Hence, the standard internal
 function library is a rich source of coding examples for user-defined
 C functions.)
 Two different calling conventions are currently used for C functions.
 The newer "version 1" calling convention is indicated by writing
 a <TT
CLASS="LITERAL"
>PG_FUNCTION_INFO_V1()</TT
> macro call for the function,
 as illustrated below. Lack of such a macro indicates an old-style
 ("version 0") function. The language name specified in <TT
CLASS="COMMAND"
>CREATE FUNCTION</TT
>
 is <TT
CLASS="LITERAL"
>C</TT
> in either case. Old-style functions are now deprecated
 because of portability problems and lack of functionality, but they
 are still supported for compatibility reasons.
 <DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="XFUNC-C-DYNLOAD"
>35.9.1. Dynamic Loading</A
></H2
> The first time a user-defined function in a particular
 loadable object file is called in a session,
 the dynamic loader loads that object file into memory so that the
 function can be called. The <TT
CLASS="COMMAND"
>CREATE FUNCTION</TT
>
 for a user-defined C function must therefore specify two pieces of
 information for the function: the name of the loadable
 object file, and the C name (link symbol) of the specific function to call
 within that object file. If the C name is not explicitly specified then
 it is assumed to be the same as the SQL function name.
 The following algorithm is used to locate the shared object file
 based on the name given in the <TT
CLASS="COMMAND"
>CREATE FUNCTION</TT
>
 command:

<OL
TYPE="1"
><LI
> If the name is an absolute path, the given file is loaded.
 </LI
><LI
> If the name starts with the string <TT
CLASS="LITERAL"
>$libdir</TT
>,
 that part is replaced by the PostgreSQL package
 library directory
 name, which is determined at build time.
 </LI
><LI
> If the name does not contain a directory part, the file is
 searched for in the path specified by the configuration variable
 <A
HREF="runtime-config-client.html#GUC-DYNAMIC-LIBRARY-PATH"
>dynamic_library_path</A
>.
 </LI
><LI
> Otherwise (the file was not found in the path, or it contains a
 non-absolute directory part), the dynamic loader will try to
 take the name as given, which will most likely fail. (It is
 unreliable to depend on the current working directory.)
 </LI
></OL
>

If this sequence does not work, the platform-specific shared
 library file name extension (often <TT
CLASS="FILENAME"
>.so</TT
>) is
 appended to the given name and this sequence is tried again. If
 that fails as well, the load will fail.
 It is recommended to locate shared libraries either relative to
 <TT
CLASS="LITERAL"
>$libdir</TT
> or through the dynamic library path.
 This simplifies version upgrades if the new installation is at a
 different location. The actual directory that
 <TT
CLASS="LITERAL"
>$libdir</TT
> stands for can be found out with the
 command <TT
CLASS="LITERAL"
>pg_config --pkglibdir</TT
>.
 The user ID the PostgreSQL server runs
 as must be able to traverse the path to the file you intend to
 load. Making the file or a higher-level directory not readable
 and/or not executable by the postgres
 user is a common mistake.
 In any case, the file name that is given in the
 <TT
CLASS="COMMAND"
>CREATE FUNCTION</TT
> command is recorded literally
 in the system catalogs, so if the file needs to be loaded again
 the same procedure is applied.
 <DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
>Note: PostgreSQL will not compile a C function
 automatically. The object file must be compiled before it is referenced
 in a <TT
CLASS="COMMAND"
>CREATE
 FUNCTION</TT
> command. See <A
HREF="xfunc-c.html#DFUNC"
>Section 35.9.6</A
> for additional
 information.
 </BLOCKQUOTE
></DIV
> To ensure that a dynamically loaded object file is not loaded into an
 incompatible server, PostgreSQL checks that the
 file contains a "magic block" with the appropriate contents.
 This allows the server to detect obvious incompatibilities, such as code
 compiled for a different major version of
 PostgreSQL. A magic block is required as of
 PostgreSQL 8.2. To include a magic block,
 write this in one (and only one) of the module source files, after having
 included the header <TT
CLASS="FILENAME"
>fmgr.h</TT
>:

<PRE
CLASS="PROGRAMLISTING"
>#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif</PRE
>

The <TT
CLASS="LITERAL"
>#ifdef</TT
> test can be omitted if the code doesn't
 need to compile against pre-8.2 PostgreSQL
 releases.
 After it is used for the first time, a dynamically loaded object
 file is retained in memory. Future calls in the same session to
 the function(s) in that file will only incur the small overhead of
 a symbol table lookup. If you need to force a reload of an object
 file, for example after recompiling it, begin a fresh session.
 Optionally, a dynamically loaded file can contain initialization and
 finalization functions. If the file includes a function named
 <CODE
CLASS="FUNCTION"
>_PG_init</CODE
>, that function will be called immediately after
 loading the file. The function receives no parameters and should
 return void. If the file includes a function named
 <CODE
CLASS="FUNCTION"
>_PG_fini</CODE
>, that function will be called immediately before
 unloading the file. Likewise, the function receives no parameters and
 should return void. Note that <CODE
CLASS="FUNCTION"
>_PG_fini</CODE
> will only be called
 during an unload of the file, not during process termination.
 (Presently, unloads are disabled and will never occur, but this may
 change in the future.)
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="XFUNC-C-BASETYPE"
>35.9.2. Base Types in C-Language Functions</A
></H2
> To know how to write C-language functions, you need to know how
 PostgreSQL internally represents base
 data types and how they can be passed to and from functions.
 Internally, PostgreSQL regards a base
 type as a "blob of memory". The user-defined
 functions that you define over a type in turn define the way that
 PostgreSQL can operate on it. That
 is, PostgreSQL will only store and
 retrieve the data from disk and use your user-defined functions
 to input, process, and output the data.
 Base types can have one of three internal formats:

<UL
><LI
> pass by value, fixed-length
 </LI
><LI
> pass by reference, fixed-length
 </LI
><LI
> pass by reference, variable-length
 </LI
></UL
>
 By-value types can only be 1, 2, or 4 bytes in length
 (also 8 bytes, if <TT
CLASS="LITERAL"
>sizeof(Datum)</TT
> is 8 on your machine).
 You should be careful to define your types such that they will be the
 same size (in bytes) on all architectures. For example, the
 <TT
CLASS="LITERAL"
>long</TT
> type is dangerous because it is 4 bytes on some
 machines and 8 bytes on others, whereas <TT
CLASS="TYPE"
>int</TT
> type is 4 bytes
 on most Unix machines. A reasonable implementation of the
 <TT
CLASS="TYPE"
>int4</TT
> type on Unix machines might be:

<PRE
CLASS="PROGRAMLISTING"
>/* 4-byte integer, passed by value */
typedef int int4;</PRE
>
 On the other hand, fixed-length types of any size can
 be passed by-reference. For example, here is a sample
 implementation of a PostgreSQL type:

<PRE
CLASS="PROGRAMLISTING"
>/* 16-byte structure, passed by reference */
typedef struct
{
 double x, y;
} Point;</PRE
>

Only pointers to such types can be used when passing
 them in and out of PostgreSQL functions.
 To return a value of such a type, allocate the right amount of
 memory with <TT
CLASS="LITERAL"
>palloc</TT
>, fill in the allocated memory,
 and return a pointer to it. (Also, if you just want to return the
 same value as one of your input arguments that's of the same data type,
 you can skip the extra <TT
CLASS="LITERAL"
>palloc</TT
> and just return the
 pointer to the input value.)
 Finally, all variable-length types must also be passed
 by reference. All variable-length types must begin
 with an opaque length field of exactly 4 bytes, which will be set
 by <TT
CLASS="SYMBOL"
>SET_VARSIZE</TT
>; never set this field directly! All data to
 be stored within that type must be located in the memory
 immediately following that length field. The
 length field contains the total length of the structure,
 that is, it includes the size of the length field
 itself.
 Another important point is to avoid leaving any uninitialized bits
 within data type values; for example, take care to zero out any
 alignment padding bytes that might be present in structs. Without
 this, logically-equivalent constants of your data type might be
 seen as unequal by the planner, leading to inefficient (though not
 incorrect) plans.
 <DIV
CLASS="WARNING"
><TABLE
CLASS="WARNING"
BORDER="1"
WIDTH="100%"
><TR
><TD
ALIGN="CENTER"
>Warning</TD
></TR
><TR
><TD
ALIGN="LEFT"
> Never modify the contents of a pass-by-reference input
 value. If you do so you are likely to corrupt on-disk data, since
 the pointer you are given might point directly into a disk buffer.
 The sole exception to this rule is explained in
 <A
HREF="xaggr.html"
>Section 35.10</A
>.
 </TD
></TR
></TABLE
></DIV
> As an example, we can define the type <TT
CLASS="TYPE"
>text</TT
> as
 follows:

<PRE
CLASS="PROGRAMLISTING"
>typedef struct {
 int4 length;
 char data[1];
} text;</PRE
>

Obviously, the data field declared here is not long enough to hold
 all possible strings. Since it's impossible to declare a variable-size
 structure in <ACRONYM
CLASS="ACRONYM"
>C</ACRONYM
>, we rely on the knowledge that the
 <ACRONYM
CLASS="ACRONYM"
>C</ACRONYM
> compiler won't range-check array subscripts. We
 just allocate the necessary amount of space and then access the array as
 if it were declared the right length. (This is a common trick, which
 you can read about in many textbooks about C.)
 When manipulating
 variable-length types, we must be careful to allocate
 the correct amount of memory and set the length field correctly.
 For example, if we wanted to store 40 bytes in a <TT
CLASS="STRUCTNAME"
>text</TT
>
 structure, we might use a code fragment like this:

<PRE
CLASS="PROGRAMLISTING"
>#include "postgres.h"
...
char buffer[40]; /* our source data */
...
text *destination = (text *) palloc(VARHDRSZ + 40);
SET_VARSIZE(destination, VARHDRSZ + 40);
memcpy(destination-&#62;data, buffer, 40);
...</PRE
>

<TT
CLASS="LITERAL"
>VARHDRSZ</TT
> is the same as <TT
CLASS="LITERAL"
>sizeof(int32)</TT
>, but
 it's considered good style to use the macro <TT
CLASS="LITERAL"
>VARHDRSZ</TT
>
 to refer to the size of the overhead for a variable-length type.
 Also, the length field must be set using the
 <TT
CLASS="LITERAL"
>SET_VARSIZE</TT
> macro, not by simple assignment.
 <A
HREF="xfunc-c.html#XFUNC-C-TYPE-TABLE"
>Table 35-1</A
> specifies which C type
 corresponds to which SQL type when writing a C-language function
 that uses a built-in type of PostgreSQL.
 The "Defined In" column gives the header file that
 needs to be included to get the type definition. (The actual
 definition might be in a different file that is included by the
 listed file. It is recommended that users stick to the defined
 interface.) Note that you should always include
 <TT
CLASS="FILENAME"
>postgres.h</TT
> first in any source file, because
 it declares a number of things that you will need anyway.
 <DIV
CLASS="TABLE"
><A
NAME="XFUNC-C-TYPE-TABLE"
></A
>Table 35-1. Equivalent C Types for Built-in SQL Types<TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><THEAD
><TR
><TH
> SQL Type
 </TH
><TH
> C Type
 </TH
><TH
> Defined In
 </TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="TYPE"
>abstime</TT
></TD
><TD
><TT
CLASS="TYPE"
>AbsoluteTime</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/nabstime.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>boolean</TT
></TD
><TD
><TT
CLASS="TYPE"
>bool</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
> (maybe compiler built-in)</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>box</TT
></TD
><TD
><TT
CLASS="TYPE"
>BOX*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/geo_decls.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>bytea</TT
></TD
><TD
><TT
CLASS="TYPE"
>bytea*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>"char"</TT
></TD
><TD
><TT
CLASS="TYPE"
>char</TT
></TD
><TD
>(compiler built-in)</TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>character</TT
></TD
><TD
><TT
CLASS="TYPE"
>BpChar*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>cid</TT
></TD
><TD
><TT
CLASS="TYPE"
>CommandId</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>date</TT
></TD
><TD
><TT
CLASS="TYPE"
>DateADT</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/date.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>smallint</TT
> (<TT
CLASS="TYPE"
>int2</TT
>)</TD
><TD
><TT
CLASS="TYPE"
>int2</TT
> or <TT
CLASS="TYPE"
>int16</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>int2vector</TT
></TD
><TD
><TT
CLASS="TYPE"
>int2vector*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>integer</TT
> (<TT
CLASS="TYPE"
>int4</TT
>)</TD
><TD
><TT
CLASS="TYPE"
>int4</TT
> or <TT
CLASS="TYPE"
>int32</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>real</TT
> (<TT
CLASS="TYPE"
>float4</TT
>)</TD
><TD
><TT
CLASS="TYPE"
>float4*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>double precision</TT
> (<TT
CLASS="TYPE"
>float8</TT
>)</TD
><TD
><TT
CLASS="TYPE"
>float8*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>interval</TT
></TD
><TD
><TT
CLASS="TYPE"
>Interval*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>datatype/timestamp.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>lseg</TT
></TD
><TD
><TT
CLASS="TYPE"
>LSEG*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/geo_decls.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>name</TT
></TD
><TD
><TT
CLASS="TYPE"
>Name</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>oid</TT
></TD
><TD
><TT
CLASS="TYPE"
>Oid</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>oidvector</TT
></TD
><TD
><TT
CLASS="TYPE"
>oidvector*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>path</TT
></TD
><TD
><TT
CLASS="TYPE"
>PATH*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/geo_decls.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>point</TT
></TD
><TD
><TT
CLASS="TYPE"
>POINT*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/geo_decls.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>regproc</TT
></TD
><TD
><TT
CLASS="TYPE"
>regproc</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>reltime</TT
></TD
><TD
><TT
CLASS="TYPE"
>RelativeTime</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/nabstime.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
><TT
CLASS="TYPE"
>text*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>tid</TT
></TD
><TD
><TT
CLASS="TYPE"
>ItemPointer</TT
></TD
><TD
><TT
CLASS="FILENAME"
>storage/itemptr.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>time</TT
></TD
><TD
><TT
CLASS="TYPE"
>TimeADT</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/date.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>time with time zone</TT
></TD
><TD
><TT
CLASS="TYPE"
>TimeTzADT</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/date.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>timestamp</TT
></TD
><TD
><TT
CLASS="TYPE"
>Timestamp*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>datatype/timestamp.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>tinterval</TT
></TD
><TD
><TT
CLASS="TYPE"
>TimeInterval</TT
></TD
><TD
><TT
CLASS="FILENAME"
>utils/nabstime.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>varchar</TT
></TD
><TD
><TT
CLASS="TYPE"
>VarChar*</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
><TR
><TD
><TT
CLASS="TYPE"
>xid</TT
></TD
><TD
><TT
CLASS="TYPE"
>TransactionId</TT
></TD
><TD
><TT
CLASS="FILENAME"
>postgres.h</TT
></TD
></TR
></TBODY
></TABLE
></DIV
> Now that we've gone over all of the possible structures
 for base types, we can show some examples of real functions.
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN53110"
>35.9.3. Version 0 Calling Conventions</A
></H2
> We present the "old style" calling convention first &mdash; although
 this approach is now deprecated, it's easier to get a handle on
 initially. In the version-0 method, the arguments and result
 of the C function are just declared in normal C style, but being
 careful to use the C representation of each SQL data type as shown
 above.
 Here are some examples:

<PRE
CLASS="PROGRAMLISTING"
>#include "postgres.h"
#include &#60;string.h&#62;
#include "utils/geo_decls.h"

#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif

/* by value */

int
add_one(int arg)
{
    return arg + 1;
}

/* by reference, fixed length */

float8 *
add_one_float8(float8 *arg)
{
    float8    *result = (float8 *) palloc(sizeof(float8));

*result = *arg + 1.0;

return result;
}

Point *
makepoint(Point *pointx, Point *pointy)
{
    Point     *new_point = (Point *) palloc(sizeof(Point));

new_point-&#62;x = pointx-&#62;x;
    new_point-&#62;y = pointy-&#62;y;

return new_point;
}

/* by reference, variable length */

text *
copytext(text *t)
{
    /*
     * VARSIZE is the total size of the struct in bytes.
     */
    text *new_t = (text *) palloc(VARSIZE(t));
    SET_VARSIZE(new_t, VARSIZE(t));
    /*
     * VARDATA is a pointer to the data region of the struct.
     */
    memcpy((void *) VARDATA(new_t), /* destination */
           (void *) VARDATA(t),     /* source */
           VARSIZE(t) - VARHDRSZ);  /* how many bytes */
    return new_t;
}

text *
concat_text(text *arg1, text *arg2)
{
    int32 new_text_size = VARSIZE(arg1) + VARSIZE(arg2) - VARHDRSZ;
    text *new_text = (text *) palloc(new_text_size);

SET_VARSIZE(new_text, new_text_size);
 memcpy(VARDATA(new_text), VARDATA(arg1), VARSIZE(arg1) - VARHDRSZ);
 memcpy(VARDATA(new_text) + (VARSIZE(arg1) - VARHDRSZ),
 VARDATA(arg2), VARSIZE(arg2) - VARHDRSZ);
 return new_text;
}</PRE
>
 Supposing that the above code has been prepared in file
 <TT
CLASS="FILENAME"
>funcs.c</TT
> and compiled into a shared object,
 we could define the functions to PostgreSQL
 with commands like this:

<PRE
CLASS="PROGRAMLISTING"
>CREATE FUNCTION add_one(integer) RETURNS integer
 AS '<TT
CLASS="REPLACEABLE"
>DIRECTORY</TT
>/funcs', 'add_one'
 LANGUAGE C STRICT;

-- note overloading of SQL function name "add_one"
CREATE FUNCTION add_one(double precision) RETURNS double precision
 AS '<TT
CLASS="REPLACEABLE"
>DIRECTORY</TT
>/funcs', 'add_one_float8'
 LANGUAGE C STRICT;

CREATE FUNCTION makepoint(point, point) RETURNS point
 AS '<TT
CLASS="REPLACEABLE"
>DIRECTORY</TT
>/funcs', 'makepoint'
 LANGUAGE C STRICT;

CREATE FUNCTION copytext(text) RETURNS text
 AS '<TT
CLASS="REPLACEABLE"
>DIRECTORY</TT
>/funcs', 'copytext'
 LANGUAGE C STRICT;

CREATE FUNCTION concat_text(text, text) RETURNS text
 AS '<TT
CLASS="REPLACEABLE"
>DIRECTORY</TT
>/funcs', 'concat_text'
 LANGUAGE C STRICT;</PRE
>
 Here, <TT
CLASS="REPLACEABLE"
>DIRECTORY</TT
> stands for the
 directory of the shared library file (for instance the
 PostgreSQL tutorial directory, which
 contains the code for the examples used in this section).
 (Better style would be to use just <TT
CLASS="LITERAL"
>'funcs'</TT
> in the
 <TT
CLASS="LITERAL"
>AS</TT
> clause, after having added
 <TT
CLASS="REPLACEABLE"
>DIRECTORY</TT
> to the search path. In any
 case, we can omit the system-specific extension for a shared
 library, commonly <TT
CLASS="LITERAL"
>.so</TT
> or
 <TT
CLASS="LITERAL"
>.sl</TT
>.)
 Notice that we have specified the functions as "strict",
 meaning that
 the system should automatically assume a null result if any input
 value is null. By doing this, we avoid having to check for null inputs
 in the function code. Without this, we'd have to check for null values
 explicitly, by checking for a null pointer for each
 pass-by-reference argument. (For pass-by-value arguments, we don't
 even have a way to check!)
 Although this calling convention is simple to use,
 it is not very portable; on some architectures there are problems
 with passing data types that are smaller than <TT
CLASS="TYPE"
>int</TT
> this way. Also, there is
 no simple way to return a null result, nor to cope with null arguments
 in any way other than making the function strict. The version-1
 convention, presented next, overcomes these objections.
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN53137"
>35.9.4. Version 1 Calling Conventions</A
></H2
> The version-1 calling convention relies on macros to suppress most
 of the complexity of passing arguments and results. The C declaration
 of a version-1 function is always:
<PRE
CLASS="PROGRAMLISTING"
>Datum funcname(PG_FUNCTION_ARGS)</PRE
>
 In addition, the macro call:
<PRE
CLASS="PROGRAMLISTING"
>PG_FUNCTION_INFO_V1(funcname);</PRE
>
 must appear in the same source file. (Conventionally, it's
 written just before the function itself.) This macro call is not
 needed for <TT
CLASS="LITERAL"
>internal</TT
>-language functions, since
 PostgreSQL assumes that all internal functions
 use the version-1 convention. It is, however, required for
 dynamically-loaded functions.
 In a version-1 function, each actual argument is fetched using a
 <CODE
CLASS="FUNCTION"
>PG_GETARG_<TT
CLASS="REPLACEABLE"
>xxx</TT
>()</CODE
>
 macro that corresponds to the argument's data type, and the
 result is returned using a
 <CODE
CLASS="FUNCTION"
>PG_RETURN_<TT
CLASS="REPLACEABLE"
>xxx</TT
>()</CODE
>
 macro for the return type.
 <CODE
CLASS="FUNCTION"
>PG_GETARG_<TT
CLASS="REPLACEABLE"
>xxx</TT
>()</CODE
>
 takes as its argument the number of the function argument to
 fetch, where the count starts at 0.
 <CODE
CLASS="FUNCTION"
>PG_RETURN_<TT
CLASS="REPLACEABLE"
>xxx</TT
>()</CODE
>
 takes as its argument the actual value to return.
 Here we show the same functions as above, coded in version-1 style:

<PRE
CLASS="PROGRAMLISTING"
>#include "postgres.h"
#include &#60;string.h&#62;
#include "fmgr.h"
#include "utils/geo_decls.h"

#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif

/* by value */

PG_FUNCTION_INFO_V1(add_one);

Datum
add_one(PG_FUNCTION_ARGS)
{
    int32   arg = PG_GETARG_INT32(0);

PG_RETURN_INT32(arg + 1);
}

/* by reference, fixed length */

PG_FUNCTION_INFO_V1(add_one_float8);

Datum
add_one_float8(PG_FUNCTION_ARGS)
{
    /* The macros for FLOAT8 hide its pass-by-reference nature. */
    float8   arg = PG_GETARG_FLOAT8(0);

PG_RETURN_FLOAT8(arg + 1.0);
}

PG_FUNCTION_INFO_V1(makepoint);

Datum
makepoint(PG_FUNCTION_ARGS)
{
    /* Here, the pass-by-reference nature of Point is not hidden. */
    Point     *pointx = PG_GETARG_POINT_P(0);
    Point     *pointy = PG_GETARG_POINT_P(1);
    Point     *new_point = (Point *) palloc(sizeof(Point));

new_point-&#62;x = pointx-&#62;x;
    new_point-&#62;y = pointy-&#62;y;

PG_RETURN_POINT_P(new_point);
}

/* by reference, variable length */

PG_FUNCTION_INFO_V1(copytext);

Datum
copytext(PG_FUNCTION_ARGS)
{
    text     *t = PG_GETARG_TEXT_P(0);
    /*
     * VARSIZE is the total size of the struct in bytes.
     */
    text     *new_t = (text *) palloc(VARSIZE(t));
    SET_VARSIZE(new_t, VARSIZE(t));
    /*
     * VARDATA is a pointer to the data region of the struct.
     */
    memcpy((void *) VARDATA(new_t), /* destination */
           (void *) VARDATA(t),     /* source */
           VARSIZE(t) - VARHDRSZ);  /* how many bytes */
    PG_RETURN_TEXT_P(new_t);
}

PG_FUNCTION_INFO_V1(concat_text);

Datum
concat_text(PG_FUNCTION_ARGS)
{
    text  *arg1 = PG_GETARG_TEXT_P(0);
    text  *arg2 = PG_GETARG_TEXT_P(1);
    int32 new_text_size = VARSIZE(arg1) + VARSIZE(arg2) - VARHDRSZ;
    text *new_text = (text *) palloc(new_text_size);

SET_VARSIZE(new_text, new_text_size);
 memcpy(VARDATA(new_text), VARDATA(arg1), VARSIZE(arg1) - VARHDRSZ);
 memcpy(VARDATA(new_text) + (VARSIZE(arg1) - VARHDRSZ),
 VARDATA(arg2), VARSIZE(arg2) - VARHDRSZ);
 PG_RETURN_TEXT_P(new_text);
}</PRE
>
 The <TT
CLASS="COMMAND"
>CREATE FUNCTION</TT
> commands are the same as
 for the version-0 equivalents.
 At first glance, the version-1 coding conventions might appear to
 be just pointless obscurantism. They do, however, offer a number
 of improvements, because the macros can hide unnecessary detail.
 An example is that in coding <CODE
CLASS="FUNCTION"
>add_one_float8</CODE
>, we no longer need to
 be aware that <TT
CLASS="TYPE"
>float8</TT
> is a pass-by-reference type. Another
 example is that the <TT
CLASS="LITERAL"
>GETARG</TT
> macros for variable-length types allow
 for more efficient fetching of "toasted" (compressed or
 out-of-line) values.
 One big improvement in version-1 functions is better handling of null
 inputs and results. The macro <CODE
CLASS="FUNCTION"
>PG_ARGISNULL(<TT
CLASS="REPLACEABLE"
>n</TT
>)</CODE
>
 allows a function to test whether each input is null. (Of course, doing
 this is only necessary in functions not declared "strict".)
 As with the
 <CODE
CLASS="FUNCTION"
>PG_GETARG_<TT
CLASS="REPLACEABLE"
>xxx</TT
>()</CODE
> macros,
 the input arguments are counted beginning at zero. Note that one
 should refrain from executing
 <CODE
CLASS="FUNCTION"
>PG_GETARG_<TT
CLASS="REPLACEABLE"
>xxx</TT
>()</CODE
> until
 one has verified that the argument isn't null.
 To return a null result, execute <CODE
CLASS="FUNCTION"
>PG_RETURN_NULL()</CODE
>;
 this works in both strict and nonstrict functions.
 Other options provided in the new-style interface are two
 variants of the
 <CODE
CLASS="FUNCTION"
>PG_GETARG_<TT
CLASS="REPLACEABLE"
>xxx</TT
>()</CODE
>
 macros. The first of these,
 <CODE
CLASS="FUNCTION"
>PG_GETARG_<TT
CLASS="REPLACEABLE"
>xxx</TT
>_COPY()</CODE
>,
 guarantees to return a copy of the specified argument that is
 safe for writing into. (The normal macros will sometimes return a
 pointer to a value that is physically stored in a table, which
 must not be written to. Using the
 <CODE
CLASS="FUNCTION"
>PG_GETARG_<TT
CLASS="REPLACEABLE"
>xxx</TT
>_COPY()</CODE
>
 macros guarantees a writable result.)
 The second variant consists of the
 <CODE
CLASS="FUNCTION"
>PG_GETARG_<TT
CLASS="REPLACEABLE"
>xxx</TT
>_SLICE()</CODE
>
 macros which take three arguments. The first is the number of the
 function argument (as above). The second and third are the offset and
 length of the segment to be returned. Offsets are counted from
 zero, and a negative length requests that the remainder of the
 value be returned. These macros provide more efficient access to
 parts of large values in the case where they have storage type
 "external". (The storage type of a column can be specified using
 <TT
CLASS="LITERAL"
>ALTER TABLE <TT
CLASS="REPLACEABLE"
>tablename</TT
> ALTER
 COLUMN <TT
CLASS="REPLACEABLE"
>colname</TT
> SET STORAGE
 <TT
CLASS="REPLACEABLE"
>storagetype</TT
></TT
>. <TT
CLASS="REPLACEABLE"
>storagetype</TT
> is one of
 <TT
CLASS="LITERAL"
>plain</TT
>, <TT
CLASS="LITERAL"
>external</TT
>, <TT
CLASS="LITERAL"
>extended</TT
>,
 or <TT
CLASS="LITERAL"
>main</TT
>.)
 Finally, the version-1 function call conventions make it possible
 to return set results (<A
HREF="xfunc-c.html#XFUNC-C-RETURN-SET"
>Section 35.9.9</A
>) and
 implement trigger functions (<A
HREF="triggers.html"
>Chapter 36</A
>) and
 procedural-language call handlers (<A
HREF="plhandler.html"
>Chapter 49</A
>). Version-1 code is also more
 portable than version-0, because it does not break restrictions
 on function call protocol in the C standard. For more details
 see <TT
CLASS="FILENAME"
>src/backend/utils/fmgr/README</TT
> in the
 source distribution.
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN53195"
>35.9.5. Writing Code</A
></H2
> Before we turn to the more advanced topics, we should discuss
 some coding rules for PostgreSQL
 C-language functions. While it might be possible to load functions
 written in languages other than C into
 PostgreSQL, this is usually difficult
 (when it is possible at all) because other languages, such as
 C++, FORTRAN, or Pascal often do not follow the same calling
 convention as C. That is, other languages do not pass argument
 and return values between functions in the same way. For this
 reason, we will assume that your C-language functions are
 actually written in C.
 The basic rules for writing and building C functions are as follows:

<UL
><LI
> Use <TT
CLASS="LITERAL"
>pg_config
 --includedir-server</TT
>
 to find out where the PostgreSQL server header
 files are installed on your system (or the system that your
 users will be running on).
 </LI
><LI
> Compiling and linking your code so that it can be dynamically
 loaded into PostgreSQL always
 requires special flags. See <A
HREF="xfunc-c.html#DFUNC"
>Section 35.9.6</A
> for a
 detailed explanation of how to do it for your particular
 operating system.
 </LI
><LI
> Remember to define a "magic block" for your shared library,
 as described in <A
HREF="xfunc-c.html#XFUNC-C-DYNLOAD"
>Section 35.9.1</A
>.
 </LI
><LI
> When allocating memory, use the
 PostgreSQL functions
 <CODE
CLASS="FUNCTION"
>palloc</CODE
> and <CODE
CLASS="FUNCTION"
>pfree</CODE
>
 instead of the corresponding C library functions
 <CODE
CLASS="FUNCTION"
>malloc</CODE
> and <CODE
CLASS="FUNCTION"
>free</CODE
>.
 The memory allocated by <CODE
CLASS="FUNCTION"
>palloc</CODE
> will be
 freed automatically at the end of each transaction, preventing
 memory leaks.
 </LI
><LI
> Always zero the bytes of your structures using <CODE
CLASS="FUNCTION"
>memset</CODE
>
 (or allocate them with <CODE
CLASS="FUNCTION"
>palloc0</CODE
> in the first place).
 Even if you assign to each field of your structure, there might be
 alignment padding (holes in the structure) that contain
 garbage values. Without this, it's difficult to
 support hash indexes or hash joins, as you must pick out only
 the significant bits of your data structure to compute a hash.
 The planner also sometimes relies on comparing constants via
 bitwise equality, so you can get undesirable planning results if
 logically-equivalent values aren't bitwise equal.
 </LI
><LI
> Most of the internal PostgreSQL
 types are declared in <TT
CLASS="FILENAME"
>postgres.h</TT
>, while
 the function manager interfaces
 (<TT
CLASS="SYMBOL"
>PG_FUNCTION_ARGS</TT
>, etc.) are in
 <TT
CLASS="FILENAME"
>fmgr.h</TT
>, so you will need to include at
 least these two files. For portability reasons it's best to
 include <TT
CLASS="FILENAME"
>postgres.h</TT
> first,
 before any other system or user header files. Including
 <TT
CLASS="FILENAME"
>postgres.h</TT
> will also include
 <TT
CLASS="FILENAME"
>elog.h</TT
> and <TT
CLASS="FILENAME"
>palloc.h</TT
>
 for you.
 </LI
><LI
> Symbol names defined within object files must not conflict
 with each other or with symbols defined in the
 PostgreSQL server executable. You
 will have to rename your functions or variables if you get
 error messages to this effect.
 </LI
></UL
>
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="DFUNC"
>35.9.6. Compiling and Linking Dynamically-loaded Functions</A
></H2
> Before you are able to use your
 PostgreSQL extension functions written in
 C, they must be compiled and linked in a special way to produce a
 file that can be dynamically loaded by the server. To be precise, a
 shared library needs to be
 created.

For information beyond what is contained in this section
 you should read the documentation of your
 operating system, in particular the manual pages for the C compiler,
 <TT
CLASS="COMMAND"
>cc</TT
>, and the link editor, <TT
CLASS="COMMAND"
>ld</TT
>.
 In addition, the PostgreSQL source code
 contains several working examples in the
 <TT
CLASS="FILENAME"
>contrib</TT
> directory. If you rely on these
 examples you will make your modules dependent on the availability
 of the PostgreSQL source code, however.
 Creating shared libraries is generally analogous to linking
 executables: first the source files are compiled into object files,
 then the object files are linked together. The object files need to
 be created as position-independent code
 (<ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
>), which
 conceptually means that they can be placed at an arbitrary location
 in memory when they are loaded by the executable. (Object files
 intended for executables are usually not compiled that way.) The
 command to link a shared library contains special flags to
 distinguish it from linking an executable (at least in theory
 &mdash; on some systems the practice is much uglier).
 In the following examples we assume that your source code is in a
 file <TT
CLASS="FILENAME"
>foo.c</TT
> and we will create a shared library
 <TT
CLASS="FILENAME"
>foo.so</TT
>. The intermediate object file will be
 called <TT
CLASS="FILENAME"
>foo.o</TT
> unless otherwise noted. A shared
 library can contain more than one object file, but we only use one
 here.
 <DIV
CLASS="VARIABLELIST"
><DL
><DT
>FreeBSD</DT
><DD
> The compiler flag to create <ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
> is
 <TT
CLASS="OPTION"
>-fPIC</TT
>. To create shared libraries the compiler
 flag is <TT
CLASS="OPTION"
>-shared</TT
>.
<PRE
CLASS="PROGRAMLISTING"
>gcc -fPIC -c foo.c
gcc -shared -o foo.so foo.o</PRE
>
 This is applicable as of version 3.0 of
 FreeBSD.
 </DD
><DT
>HP-UX</DT
><DD
> The compiler flag of the system compiler to create
 <ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
> is <TT
CLASS="OPTION"
>+z</TT
>. When using
 GCC it's <TT
CLASS="OPTION"
>-fPIC</TT
>. The
 linker flag for shared libraries is <TT
CLASS="OPTION"
>-b</TT
>. So:
<PRE
CLASS="PROGRAMLISTING"
>cc +z -c foo.c</PRE
>
 or:
<PRE
CLASS="PROGRAMLISTING"
>gcc -fPIC -c foo.c</PRE
>
 and then:
<PRE
CLASS="PROGRAMLISTING"
>ld -b -o foo.sl foo.o</PRE
>
 HP-UX uses the extension
 <TT
CLASS="FILENAME"
>.sl</TT
> for shared libraries, unlike most other
 systems.
 </DD
><DT
>IRIX</DT
><DD
> <ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
> is the default, no special compiler
 options are necessary. The linker option to produce shared
 libraries is <TT
CLASS="OPTION"
>-shared</TT
>.
<PRE
CLASS="PROGRAMLISTING"
>cc -c foo.c
ld -shared -o foo.so foo.o</PRE
>
 </DD
><DT
>Linux</DT
><DD
> The compiler flag to create <ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
> is
 <TT
CLASS="OPTION"
>-fPIC</TT
>.
 The compiler flag to create a shared library is
 <TT
CLASS="OPTION"
>-shared</TT
>. A complete example looks like this:
<PRE
CLASS="PROGRAMLISTING"
>cc -fPIC -c foo.c
cc -shared -o foo.so foo.o</PRE
>
 </DD
><DT
>Mac OS X</DT
><DD
> Here is an example. It assumes the developer tools are installed.
<PRE
CLASS="PROGRAMLISTING"
>cc -c foo.c
cc -bundle -flat_namespace -undefined suppress -o foo.so foo.o</PRE
>
 </DD
><DT
>NetBSD</DT
><DD
> The compiler flag to create <ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
> is
 <TT
CLASS="OPTION"
>-fPIC</TT
>. For <ACRONYM
CLASS="ACRONYM"
>ELF</ACRONYM
> systems, the
 compiler with the flag <TT
CLASS="OPTION"
>-shared</TT
> is used to link
 shared libraries. On the older non-ELF systems, <TT
CLASS="LITERAL"
>ld
 -Bshareable</TT
> is used.
<PRE
CLASS="PROGRAMLISTING"
>gcc -fPIC -c foo.c
gcc -shared -o foo.so foo.o</PRE
>
 </DD
><DT
>OpenBSD</DT
><DD
> The compiler flag to create <ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
> is
 <TT
CLASS="OPTION"
>-fPIC</TT
>. <TT
CLASS="LITERAL"
>ld -Bshareable</TT
> is
 used to link shared libraries.
<PRE
CLASS="PROGRAMLISTING"
>gcc -fPIC -c foo.c
ld -Bshareable -o foo.so foo.o</PRE
>
 </DD
><DT
>Solaris</DT
><DD
> The compiler flag to create <ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
> is
 <TT
CLASS="OPTION"
>-KPIC</TT
> with the Sun compiler and
 <TT
CLASS="OPTION"
>-fPIC</TT
> with GCC. To
 link shared libraries, the compiler option is
 <TT
CLASS="OPTION"
>-G</TT
> with either compiler or alternatively
 <TT
CLASS="OPTION"
>-shared</TT
> with GCC.
<PRE
CLASS="PROGRAMLISTING"
>cc -KPIC -c foo.c
cc -G -o foo.so foo.o</PRE
>
 or
<PRE
CLASS="PROGRAMLISTING"
>gcc -fPIC -c foo.c
gcc -G -o foo.so foo.o</PRE
>
 </DD
><DT
>Tru64 UNIX</DT
><DD
> <ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
> is the default, so the compilation command
 is the usual one. <TT
CLASS="COMMAND"
>ld</TT
> with special options is
 used to do the linking.
<PRE
CLASS="PROGRAMLISTING"
>cc -c foo.c
ld -shared -expect_unresolved '*' -o foo.so foo.o</PRE
>
 The same procedure is used with GCC instead of the system
 compiler; no special options are required.
 </DD
><DT
>UnixWare</DT
><DD
> The compiler flag to create <ACRONYM
CLASS="ACRONYM"
>PIC</ACRONYM
> is <TT
CLASS="OPTION"
>-K
 PIC</TT
> with the SCO compiler and <TT
CLASS="OPTION"
>-fpic</TT
>
 with GCC. To link shared libraries,
 the compiler option is <TT
CLASS="OPTION"
>-G</TT
> with the SCO compiler
 and <TT
CLASS="OPTION"
>-shared</TT
> with
 GCC.
<PRE
CLASS="PROGRAMLISTING"
>cc -K PIC -c foo.c
cc -G -o foo.so foo.o</PRE
>
 or
<PRE
CLASS="PROGRAMLISTING"
>gcc -fpic -c foo.c
gcc -shared -o foo.so foo.o</PRE
>
 </DD
></DL
></DIV
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
>Tip: If this is too complicated for you, you should consider using
 <A
HREF="http://www.gnu.org/software/libtool/"
TARGET="_top"
> GNU Libtool</A
>,
 which hides the platform differences behind a uniform interface.
 </BLOCKQUOTE
></DIV
> The resulting shared library file can then be loaded into
 PostgreSQL. When specifying the file name
 to the <TT
CLASS="COMMAND"
>CREATE FUNCTION</TT
> command, one must give it
 the name of the shared library file, not the intermediate object file.
 Note that the system's standard shared-library extension (usually
 <TT
CLASS="LITERAL"
>.so</TT
> or <TT
CLASS="LITERAL"
>.sl</TT
>) can be omitted from
 the <TT
CLASS="COMMAND"
>CREATE FUNCTION</TT
> command, and normally should
 be omitted for best portability.
 Refer back to <A
HREF="xfunc-c.html#XFUNC-C-DYNLOAD"
>Section 35.9.1</A
> about where the
 server expects to find the shared library files.
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN53419"
>35.9.7. Composite-type Arguments</A
></H2
> Composite types do not have a fixed layout like C structures.
 Instances of a composite type can contain null fields. In
 addition, composite types that are part of an inheritance
 hierarchy can have different fields than other members of the
 same inheritance hierarchy. Therefore,
 PostgreSQL provides a function
 interface for accessing fields of composite types from C.
 Suppose we want to write a function to answer the query:

<PRE
CLASS="PROGRAMLISTING"
>SELECT name, c_overpaid(emp, 1500) AS overpaid
 FROM emp
 WHERE name = 'Bill' OR name = 'Sam';</PRE
>

Using call conventions version 0, we can define
 <CODE
CLASS="FUNCTION"
>c_overpaid</CODE
> as:

<PRE
CLASS="PROGRAMLISTING"
>#include "postgres.h"
#include "executor/executor.h" /* for GetAttributeByName() */

#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif

bool
c_overpaid(HeapTupleHeader t, /* the current row of emp */
           int32 limit)
{
    bool isnull;
    int32 salary;

salary = DatumGetInt32(GetAttributeByName(t, "salary", &#38;isnull));
 if (isnull)
 return false;
 return salary &#62; limit;
}</PRE
>

In version-1 coding, the above would look like this:

<PRE
CLASS="PROGRAMLISTING"
>#include "postgres.h"
#include "executor/executor.h" /* for GetAttributeByName() */

#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif

PG_FUNCTION_INFO_V1(c_overpaid);

Datum
c_overpaid(PG_FUNCTION_ARGS)
{
    HeapTupleHeader  t = PG_GETARG_HEAPTUPLEHEADER(0);
    int32            limit = PG_GETARG_INT32(1);
    bool isnull;
    Datum salary;

salary = GetAttributeByName(t, "salary", &#38;isnull);
    if (isnull)
        PG_RETURN_BOOL(false);
    /* Alternatively, we might prefer to do PG_RETURN_NULL() for null salary. */

PG_RETURN_BOOL(DatumGetInt32(salary) &#62; limit);
}</PRE
>
 <CODE
CLASS="FUNCTION"
>GetAttributeByName</CODE
> is the
 PostgreSQL system function that
 returns attributes out of the specified row. It has
 three arguments: the argument of type <TT
CLASS="TYPE"
>HeapTupleHeader</TT
> passed
 into
 the function, the name of the desired attribute, and a
 return parameter that tells whether the attribute
 is null. <CODE
CLASS="FUNCTION"
>GetAttributeByName</CODE
> returns a <TT
CLASS="TYPE"
>Datum</TT
>
 value that you can convert to the proper data type by using the
 appropriate <CODE
CLASS="FUNCTION"
>DatumGet<TT
CLASS="REPLACEABLE"
>XXX</TT
>()</CODE
>
 macro. Note that the return value is meaningless if the null flag is
 set; always check the null flag before trying to do anything with the
 result.
 There is also <CODE
CLASS="FUNCTION"
>GetAttributeByNum</CODE
>, which selects
 the target attribute by column number instead of name.
 The following command declares the function
 <CODE
CLASS="FUNCTION"
>c_overpaid</CODE
> in SQL:

<PRE
CLASS="PROGRAMLISTING"
>CREATE FUNCTION c_overpaid(emp, integer) RETURNS boolean
 AS '<TT
CLASS="REPLACEABLE"
>DIRECTORY</TT
>/funcs', 'c_overpaid'
 LANGUAGE C STRICT;</PRE
>

Notice we have used <TT
CLASS="LITERAL"
>STRICT</TT
> so that we did not have to
 check whether the input arguments were NULL.
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN53443"
>35.9.8. Returning Rows (Composite Types)</A
></H2
> To return a row or composite-type value from a C-language
 function, you can use a special API that provides macros and
 functions to hide most of the complexity of building composite
 data types. To use this API, the source file must include:
<PRE
CLASS="PROGRAMLISTING"
>#include "funcapi.h"</PRE
>
 There are two ways you can build a composite data value (henceforth
 a "tuple"): you can build it from an array of Datum values,
 or from an array of C strings that can be passed to the input
 conversion functions of the tuple's column data types. In either
 case, you first need to obtain or construct a <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
>
 descriptor for the tuple structure. When working with Datums, you
 pass the <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
> to <CODE
CLASS="FUNCTION"
>BlessTupleDesc</CODE
>,
 and then call <CODE
CLASS="FUNCTION"
>heap_form_tuple</CODE
> for each row. When working
 with C strings, you pass the <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
> to
 <CODE
CLASS="FUNCTION"
>TupleDescGetAttInMetadata</CODE
>, and then call
 <CODE
CLASS="FUNCTION"
>BuildTupleFromCStrings</CODE
> for each row. In the case of a
 function returning a set of tuples, the setup steps can all be done
 once during the first call of the function.
 Several helper functions are available for setting up the needed
 <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
>. The recommended way to do this in most
 functions returning composite values is to call:
<PRE
CLASS="PROGRAMLISTING"
>TypeFuncClass get_call_result_type(FunctionCallInfo fcinfo,
 Oid *resultTypeId,
 TupleDesc *resultTupleDesc)</PRE
>
 passing the same <TT
CLASS="LITERAL"
>fcinfo</TT
> struct passed to the calling function
 itself. (This of course requires that you use the version-1
 calling conventions.) <TT
CLASS="VARNAME"
>resultTypeId</TT
> can be specified
 as <TT
CLASS="LITERAL"
>NULL</TT
> or as the address of a local variable to receive the
 function's result type OID. <TT
CLASS="VARNAME"
>resultTupleDesc</TT
> should be the
 address of a local <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
> variable. Check that the
 result is <TT
CLASS="LITERAL"
>TYPEFUNC_COMPOSITE</TT
>; if so,
 <TT
CLASS="VARNAME"
>resultTupleDesc</TT
> has been filled with the needed
 <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
>. (If it is not, you can report an error along
 the lines of "function returning record called in context that
 cannot accept type record".)
 <DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
>Tip: <CODE
CLASS="FUNCTION"
>get_call_result_type</CODE
> can resolve the actual type of a
 polymorphic function result; so it is useful in functions that return
 scalar polymorphic results, not only functions that return composites.
 The <TT
CLASS="VARNAME"
>resultTypeId</TT
> output is primarily useful for functions
 returning polymorphic scalars.
 </BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
>Note: <CODE
CLASS="FUNCTION"
>get_call_result_type</CODE
> has a sibling
 <CODE
CLASS="FUNCTION"
>get_expr_result_type</CODE
>, which can be used to resolve the
 expected output type for a function call represented by an expression
 tree. This can be used when trying to determine the result type from
 outside the function itself. There is also
 <CODE
CLASS="FUNCTION"
>get_func_result_type</CODE
>, which can be used when only the
 function's OID is available. However these functions are not able
 to deal with functions declared to return <TT
CLASS="STRUCTNAME"
>record</TT
>, and
 <CODE
CLASS="FUNCTION"
>get_func_result_type</CODE
> cannot resolve polymorphic types,
 so you should preferentially use <CODE
CLASS="FUNCTION"
>get_call_result_type</CODE
>.
 </BLOCKQUOTE
></DIV
> Older, now-deprecated functions for obtaining
 <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
>s are:
<PRE
CLASS="PROGRAMLISTING"
>TupleDesc RelationNameGetTupleDesc(const char *relname)</PRE
>
 to get a <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
> for the row type of a named relation,
 and:
<PRE
CLASS="PROGRAMLISTING"
>TupleDesc TypeGetTupleDesc(Oid typeoid, List *colaliases)</PRE
>
 to get a <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
> based on a type OID. This can
 be used to get a <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
> for a base or
 composite type. It will not work for a function that returns
 <TT
CLASS="STRUCTNAME"
>record</TT
>, however, and it cannot resolve polymorphic
 types.
 Once you have a <TT
CLASS="STRUCTNAME"
>TupleDesc</TT
>, call:
<PRE
CLASS="PROGRAMLISTING"
>TupleDesc BlessTupleDesc(TupleDesc tupdesc)</PRE
>
 if you plan to work with Datums, or:
<PRE
CLASS="PROGRAMLISTING"
>AttInMetadata *TupleDescGetAttInMetadata(TupleDesc tupdesc)</PRE
>
 if you plan to work with C strings. If you are writing a function
 returning set, you can save the results of these functions in the
 <TT
CLASS="STRUCTNAME"
>FuncCallContext</TT
> structure &mdash; use the
 <TT
CLASS="STRUCTFIELD"
>tuple_desc</TT
> or <TT
CLASS="STRUCTFIELD"
>attinmeta</TT
> field
 respectively.
 When working with Datums, use:
<PRE
CLASS="PROGRAMLISTING"
>HeapTuple heap_form_tuple(TupleDesc tupdesc, Datum *values, bool *isnull)</PRE
>
 to build a <TT
CLASS="STRUCTNAME"
>HeapTuple</TT
> given user data in Datum form.
 When working with C strings, use:
<PRE
CLASS="PROGRAMLISTING"
>HeapTuple BuildTupleFromCStrings(AttInMetadata *attinmeta, char **values)</PRE
>
 to build a <TT
CLASS="STRUCTNAME"
>HeapTuple</TT
> given user data
 in C string form. <TT
CLASS="LITERAL"
>values</TT
> is an array of C strings,
 one for each attribute of the return row. Each C string should be in
 the form expected by the input function of the attribute data
 type. In order to return a null value for one of the attributes,
 the corresponding pointer in the <TT
CLASS="PARAMETER"
>values</TT
> array
 should be set to <TT
CLASS="SYMBOL"
>NULL</TT
>. This function will need to
 be called again for each row you return.
 Once you have built a tuple to return from your function, it
 must be converted into a <TT
CLASS="TYPE"
>Datum</TT
>. Use:
<PRE
CLASS="PROGRAMLISTING"
>HeapTupleGetDatum(HeapTuple tuple)</PRE
>
 to convert a <TT
CLASS="STRUCTNAME"
>HeapTuple</TT
> into a valid Datum. This
 <TT
CLASS="TYPE"
>Datum</TT
> can be returned directly if you intend to return
 just a single row, or it can be used as the current return value
 in a set-returning function.
 An example appears in the next section.
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="XFUNC-C-RETURN-SET"
>35.9.9. Returning Sets</A
></H2
> There is also a special API that provides support for returning
 sets (multiple rows) from a C-language function. A set-returning
 function must follow the version-1 calling conventions. Also,
 source files must include <TT
CLASS="FILENAME"
>funcapi.h</TT
>, as
 above.
 A set-returning function (<ACRONYM
CLASS="ACRONYM"
>SRF</ACRONYM
>) is called
 once for each item it returns. The <ACRONYM
CLASS="ACRONYM"
>SRF</ACRONYM
> must
 therefore save enough state to remember what it was doing and
 return the next item on each call.
 The structure <TT
CLASS="STRUCTNAME"
>FuncCallContext</TT
> is provided to help
 control this process. Within a function, <TT
CLASS="LITERAL"
>fcinfo-&gt;flinfo-&gt;fn_extra</TT
>
 is used to hold a pointer to <TT
CLASS="STRUCTNAME"
>FuncCallContext</TT
>
 across calls.
<PRE
CLASS="PROGRAMLISTING"
>typedef struct
{
 /*
 * Number of times we've been called before
 *
 * call_cntr is initialized to 0 for you by SRF_FIRSTCALL_INIT(), and
 * incremented for you every time SRF_RETURN_NEXT() is called.
 */
 uint32 call_cntr;

/*
     * OPTIONAL maximum number of calls
     *
     * max_calls is here for convenience only and setting it is optional.
     * If not set, you must provide alternative means to know when the
     * function is done.
     */
    uint32 max_calls;

/*
     * OPTIONAL pointer to result slot
     *
     * This is obsolete and only present for backward compatibility, viz,
     * user-defined SRFs that use the deprecated TupleDescGetSlot().
     */
    TupleTableSlot *slot;

/*
     * OPTIONAL pointer to miscellaneous user-provided context information
     *
     * user_fctx is for use as a pointer to your own data to retain
     * arbitrary context information between calls of your function.
     */
    void *user_fctx;

/*
     * OPTIONAL pointer to struct containing attribute type input metadata
     *
     * attinmeta is for use when returning tuples (i.e., composite data types)
     * and is not used when returning base data types. It is only needed
     * if you intend to use BuildTupleFromCStrings() to create the return
     * tuple.
     */
    AttInMetadata *attinmeta;

/*
     * memory context used for structures that must live for multiple calls
     *
     * multi_call_memory_ctx is set by SRF_FIRSTCALL_INIT() for you, and used
     * by SRF_RETURN_DONE() for cleanup. It is the most appropriate memory
     * context for any memory that is to be reused across multiple calls
     * of the SRF.
     */
    MemoryContext multi_call_memory_ctx;

/*
     * OPTIONAL pointer to struct containing tuple description
     *
     * tuple_desc is for use when returning tuples (i.e., composite data types)
     * and is only needed if you are going to build the tuples with
     * heap_form_tuple() rather than with BuildTupleFromCStrings().  Note that
     * the TupleDesc pointer stored here should usually have been run through
     * BlessTupleDesc() first.
     */
    TupleDesc tuple_desc;

} FuncCallContext;</PRE
>
 An <ACRONYM
CLASS="ACRONYM"
>SRF</ACRONYM
> uses several functions and macros that
 automatically manipulate the <TT
CLASS="STRUCTNAME"
>FuncCallContext</TT
>
 structure (and expect to find it via <TT
CLASS="LITERAL"
>fn_extra</TT
>). Use:
<PRE
CLASS="PROGRAMLISTING"
>SRF_IS_FIRSTCALL()</PRE
>
 to determine if your function is being called for the first or a
 subsequent time. On the first call (only) use:
<PRE
CLASS="PROGRAMLISTING"
>SRF_FIRSTCALL_INIT()</PRE
>
 to initialize the <TT
CLASS="STRUCTNAME"
>FuncCallContext</TT
>. On every function call,
 including the first, use:
<PRE
CLASS="PROGRAMLISTING"
>SRF_PERCALL_SETUP()</PRE
>
 to properly set up for using the <TT
CLASS="STRUCTNAME"
>FuncCallContext</TT
>
 and clearing any previously returned data left over from the
 previous pass.
 If your function has data to return, use:
<PRE
CLASS="PROGRAMLISTING"
>SRF_RETURN_NEXT(funcctx, result)</PRE
>
 to return it to the caller. (<TT
CLASS="LITERAL"
>result</TT
> must be of type
 <TT
CLASS="TYPE"
>Datum</TT
>, either a single value or a tuple prepared as
 described above.) Finally, when your function is finished
 returning data, use:
<PRE
CLASS="PROGRAMLISTING"
>SRF_RETURN_DONE(funcctx)</PRE
>
 to clean up and end the <ACRONYM
CLASS="ACRONYM"
>SRF</ACRONYM
>.
 The memory context that is current when the <ACRONYM
CLASS="ACRONYM"
>SRF</ACRONYM
> is called is
 a transient context that will be cleared between calls. This means
 that you do not need to call <CODE
CLASS="FUNCTION"
>pfree</CODE
> on everything
 you allocated using <CODE
CLASS="FUNCTION"
>palloc</CODE
>; it will go away anyway. However, if you want to allocate
 any data structures to live across calls, you need to put them somewhere
 else. The memory context referenced by
 <TT
CLASS="STRUCTFIELD"
>multi_call_memory_ctx</TT
> is a suitable location for any
 data that needs to survive until the <ACRONYM
CLASS="ACRONYM"
>SRF</ACRONYM
> is finished running. In most
 cases, this means that you should switch into
 <TT
CLASS="STRUCTFIELD"
>multi_call_memory_ctx</TT
> while doing the first-call setup.
 A complete pseudo-code example looks like the following:
<PRE
CLASS="PROGRAMLISTING"
>Datum
my_set_returning_function(PG_FUNCTION_ARGS)
{
 FuncCallContext *funcctx;
 Datum result;
 <TT
CLASS="REPLACEABLE"
>further declarations as needed</TT
>

if (SRF_IS_FIRSTCALL())
    {
        MemoryContext oldcontext;

funcctx = SRF_FIRSTCALL_INIT();
 oldcontext = MemoryContextSwitchTo(funcctx-&gt;multi_call_memory_ctx);
 /* One-time setup code appears here: */
 <TT
CLASS="REPLACEABLE"
>user code</TT
>
 <TT
CLASS="REPLACEABLE"
>if returning composite</TT
>
 <TT
CLASS="REPLACEABLE"
>build TupleDesc, and perhaps AttInMetadata</TT
>
 <TT
CLASS="REPLACEABLE"
>endif returning composite</TT
>
 <TT
CLASS="REPLACEABLE"
>user code</TT
>
 MemoryContextSwitchTo(oldcontext);
 }

/* Each-time setup code appears here: */
 <TT
CLASS="REPLACEABLE"
>user code</TT
>
 funcctx = SRF_PERCALL_SETUP();
 <TT
CLASS="REPLACEABLE"
>user code</TT
>

/* this is just one way we might test whether we are done: */
 if (funcctx-&gt;call_cntr &lt; funcctx-&gt;max_calls)
 {
 /* Here we want to return another item: */
 <TT
CLASS="REPLACEABLE"
>user code</TT
>
 <TT
CLASS="REPLACEABLE"
>obtain result Datum</TT
>
 SRF_RETURN_NEXT(funcctx, result);
 }
 else
 {
 /* Here we are done returning items and just need to clean up: */
 <TT
CLASS="REPLACEABLE"
>user code</TT
>
 SRF_RETURN_DONE(funcctx);
 }
}</PRE
>
 A complete example of a simple <ACRONYM
CLASS="ACRONYM"
>SRF</ACRONYM
> returning a composite type
 looks like:
<PRE
CLASS="PROGRAMLISTING"
>PG_FUNCTION_INFO_V1(retcomposite);

Datum
retcomposite(PG_FUNCTION_ARGS)
{
    FuncCallContext     *funcctx;
    int                  call_cntr;
    int                  max_calls;
    TupleDesc            tupdesc;
    AttInMetadata       *attinmeta;

/* stuff done only on the first call of the function */
    if (SRF_IS_FIRSTCALL())
    {
        MemoryContext   oldcontext;

/* create a function context for cross-call persistence */
        funcctx = SRF_FIRSTCALL_INIT();

/* switch to memory context appropriate for multiple function calls */
        oldcontext = MemoryContextSwitchTo(funcctx-&#62;multi_call_memory_ctx);

/* total number of tuples to be returned */
        funcctx-&#62;max_calls = PG_GETARG_UINT32(0);

/* Build a tuple descriptor for our result type */
        if (get_call_result_type(fcinfo, NULL, &#38;tupdesc) != TYPEFUNC_COMPOSITE)
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("function returning record called in context "
                            "that cannot accept type record")));

/*
         * generate attribute metadata needed later to produce tuples from raw
         * C strings
         */
        attinmeta = TupleDescGetAttInMetadata(tupdesc);
        funcctx-&#62;attinmeta = attinmeta;

MemoryContextSwitchTo(oldcontext);
    }

/* stuff done on every call of the function */
    funcctx = SRF_PERCALL_SETUP();

call_cntr = funcctx-&#62;call_cntr;
    max_calls = funcctx-&#62;max_calls;
    attinmeta = funcctx-&#62;attinmeta;

if (call_cntr &#60; max_calls)    /* do when there is more left to send */
    {
        char       **values;
        HeapTuple    tuple;
        Datum        result;

/*
         * Prepare a values array for building the returned tuple.
         * This should be an array of C strings which will
         * be processed later by the type input functions.
         */
        values = (char **) palloc(3 * sizeof(char *));
        values[0] = (char *) palloc(16 * sizeof(char));
        values[1] = (char *) palloc(16 * sizeof(char));
        values[2] = (char *) palloc(16 * sizeof(char));

snprintf(values[0], 16, "%d", 1 * PG_GETARG_INT32(1));
        snprintf(values[1], 16, "%d", 2 * PG_GETARG_INT32(1));
        snprintf(values[2], 16, "%d", 3 * PG_GETARG_INT32(1));

/* build a tuple */
        tuple = BuildTupleFromCStrings(attinmeta, values);

/* make the tuple into a datum */
        result = HeapTupleGetDatum(tuple);

/* clean up (this is not really necessary) */
        pfree(values[0]);
        pfree(values[1]);
        pfree(values[2]);
        pfree(values);

SRF_RETURN_NEXT(funcctx, result);
 }
 else /* do when there is no more left */
 {
 SRF_RETURN_DONE(funcctx);
 }
}</PRE
>

One way to declare this function in SQL is:
<PRE
CLASS="PROGRAMLISTING"
>CREATE TYPE __retcomposite AS (f1 integer, f2 integer, f3 integer);

CREATE OR REPLACE FUNCTION retcomposite(integer, integer)
 RETURNS SETOF __retcomposite
 AS '<TT
CLASS="REPLACEABLE"
>filename</TT
>', 'retcomposite'
 LANGUAGE C IMMUTABLE STRICT;</PRE
>
 A different way is to use OUT parameters:
<PRE
CLASS="PROGRAMLISTING"
>CREATE OR REPLACE FUNCTION retcomposite(IN integer, IN integer,
 OUT f1 integer, OUT f2 integer, OUT f3 integer)
 RETURNS SETOF record
 AS '<TT
CLASS="REPLACEABLE"
>filename</TT
>', 'retcomposite'
 LANGUAGE C IMMUTABLE STRICT;</PRE
>
 Notice that in this method the output type of the function is formally
 an anonymous <TT
CLASS="STRUCTNAME"
>record</TT
> type.
 The directory <A
HREF="tablefunc.html"
>contrib/tablefunc</A
>
 module in the source distribution contains more examples of
 set-returning functions.
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN53566"
>35.9.10. Polymorphic Arguments and Return Types</A
></H2
> C-language functions can be declared to accept and
 return the polymorphic types
 <TT
CLASS="TYPE"
>anyelement</TT
>, <TT
CLASS="TYPE"
>anyarray</TT
>, <TT
CLASS="TYPE"
>anynonarray</TT
>,
 <TT
CLASS="TYPE"
>anyenum</TT
>, and <TT
CLASS="TYPE"
>anyrange</TT
>.
 See <A
HREF="extend-type-system.html#EXTEND-TYPES-POLYMORPHIC"
>Section 35.2.5</A
> for a more detailed explanation
 of polymorphic functions. When function arguments or return types
 are defined as polymorphic types, the function author cannot know
 in advance what data type it will be called with, or
 need to return. There are two routines provided in <TT
CLASS="FILENAME"
>fmgr.h</TT
>
 to allow a version-1 C function to discover the actual data types
 of its arguments and the type it is expected to return. The routines are
 called <TT
CLASS="LITERAL"
>get_fn_expr_rettype(FmgrInfo *flinfo)</TT
> and
 <TT
CLASS="LITERAL"
>get_fn_expr_argtype(FmgrInfo *flinfo, int argnum)</TT
>.
 They return the result or argument type OID, or <TT
CLASS="SYMBOL"
>InvalidOid</TT
> if the
 information is not available.
 The structure <TT
CLASS="LITERAL"
>flinfo</TT
> is normally accessed as
 <TT
CLASS="LITERAL"
>fcinfo-&gt;flinfo</TT
>. The parameter <TT
CLASS="LITERAL"
>argnum</TT
>
 is zero based. <CODE
CLASS="FUNCTION"
>get_call_result_type</CODE
> can also be used
 as an alternative to <CODE
CLASS="FUNCTION"
>get_fn_expr_rettype</CODE
>.
 For example, suppose we want to write a function to accept a single
 element of any type, and return a one-dimensional array of that type:

<PRE
CLASS="PROGRAMLISTING"
>PG_FUNCTION_INFO_V1(make_array);
Datum
make_array(PG_FUNCTION_ARGS)
{
 ArrayType *result;
 Oid element_type = get_fn_expr_argtype(fcinfo-&gt;flinfo, 0);
 Datum element;
 bool isnull;
 int16 typlen;
 bool typbyval;
 char typalign;
 int ndims;
 int dims[MAXDIM];
 int lbs[MAXDIM];

if (!OidIsValid(element_type))
        elog(ERROR, "could not determine data type of input");

/* get the provided element, being careful in case it's NULL */
    isnull = PG_ARGISNULL(0);
    if (isnull)
        element = (Datum) 0;
    else
        element = PG_GETARG_DATUM(0);

/* we have one dimension */
    ndims = 1;
    /* and one element */
    dims[0] = 1;
    /* and lower bound is 1 */
    lbs[0] = 1;

/* get required info about the element type */
    get_typlenbyvalalign(element_type, &amp;typlen, &amp;typbyval, &amp;typalign);

/* now build the array */
    result = construct_md_array(&amp;element, &amp;isnull, ndims, dims, lbs,
                                element_type, typlen, typbyval, typalign);

PG_RETURN_ARRAYTYPE_P(result);
}</PRE
>
 The following command declares the function
 <CODE
CLASS="FUNCTION"
>make_array</CODE
> in SQL:

<PRE
CLASS="PROGRAMLISTING"
>CREATE FUNCTION make_array(anyelement) RETURNS anyarray
 AS '<TT
CLASS="REPLACEABLE"
>DIRECTORY</TT
>/funcs', 'make_array'
 LANGUAGE C IMMUTABLE;</PRE
>
 There is a variant of polymorphism that is only available to C-language
 functions: they can be declared to take parameters of type
 <TT
CLASS="LITERAL"
>"any"</TT
>. (Note that this type name must be double-quoted,
 since it's also a SQL reserved word.) This works like
 <TT
CLASS="TYPE"
>anyelement</TT
> except that it does not constrain different
 <TT
CLASS="LITERAL"
>"any"</TT
> arguments to be the same type, nor do they help
 determine the function's result type. A C-language function can also
 declare its final parameter to be <TT
CLASS="LITERAL"
>VARIADIC "any"</TT
>. This will
 match one or more actual arguments of any type (not necessarily the same
 type). These arguments will not be gathered into an array
 as happens with normal variadic functions; they will just be passed to
 the function separately. The <CODE
CLASS="FUNCTION"
>PG_NARGS()</CODE
> macro and the
 methods described above must be used to determine the number of actual
 arguments and their types when using this feature.
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="XFUNC-TRANSFORM-FUNCTIONS"
>35.9.11. Transform Functions</A
></H2
> Some function calls can be simplified during planning based on
 properties specific to the function. For example,
 <TT
CLASS="LITERAL"
>int4mul(n, 1)</TT
> could be simplified to just <TT
CLASS="LITERAL"
>n</TT
>.
 To define such function-specific optimizations, write a
 transform function and place its OID in the
 <TT
CLASS="STRUCTFIELD"
>protransform</TT
> field of the primary function's
 <TT
CLASS="STRUCTNAME"
>pg_proc</TT
> entry. The transform function must have the SQL
 signature <TT
CLASS="LITERAL"
>protransform(internal) RETURNS internal</TT
>. The
 argument, actually <TT
CLASS="TYPE"
>FuncExpr *</TT
>, is a dummy node representing a
 call to the primary function. If the transform function's study of the
 expression tree proves that a simplified expression tree can substitute
 for all possible concrete calls represented thereby, build and return
 that simplified expression. Otherwise, return a <TT
CLASS="LITERAL"
>NULL</TT
>
 pointer (not a SQL null).
 We make no guarantee that PostgreSQL will never call the
 primary function in cases that the transform function could simplify.
 Ensure rigorous equivalence between the simplified expression and an
 actual call to the primary function.
 Currently, this facility is not exposed to users at the SQL level
 because of security concerns, so it is only practical to use for
 optimizing built-in functions.
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN53612"
>35.9.12. Shared Memory and LWLocks</A
></H2
> Add-ins can reserve LWLocks and an allocation of shared memory on server
 startup. The add-in's shared library must be preloaded by specifying
 it in
 <A
HREF="runtime-config-resource.html#GUC-SHARED-PRELOAD-LIBRARIES"
>shared_preload_libraries</A
>.
 Shared memory is reserved by calling:
<PRE
CLASS="PROGRAMLISTING"
>void RequestAddinShmemSpace(int size)</PRE
>
 from your <CODE
CLASS="FUNCTION"
>_PG_init</CODE
> function.
 LWLocks are reserved by calling:
<PRE
CLASS="PROGRAMLISTING"
>void RequestAddinLWLocks(int n)</PRE
>
 from <CODE
CLASS="FUNCTION"
>_PG_init</CODE
>.
 To avoid possible race-conditions, each backend should use the LWLock
 <CODE
CLASS="FUNCTION"
>AddinShmemInitLock</CODE
> when connecting to and initializing
 its allocation of shared memory, as shown here:
<PRE
CLASS="PROGRAMLISTING"
>static mystruct *ptr = NULL;

if (!ptr)
{
        bool    found;

LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
 ptr = ShmemInitStruct("my struct name", size, &amp;found);
 if (!found)
 {
 initialize contents of shmem area;
 acquire any requested LWLocks using:
 ptr-&#62;mylockid = LWLockAssign();
 }
 LWLockRelease(AddinShmemInitLock);
}</PRE
>
 </DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="EXTEND-CPP"
>35.9.13. Using C++ for Extensibility</A
></H2
> Although the PostgreSQL backend is written in
 C, it is possible to write extensions in C++ if these guidelines are
 followed:

<UL
><LI
> All functions accessed by the backend must present a C interface
 to the backend; these C functions can then call C++ functions.
 For example, <TT
CLASS="LITERAL"
>extern C</TT
> linkage is required for
 backend-accessed functions. This is also necessary for any
 functions that are passed as pointers between the backend and
 C++ code.
 </LI
><LI
> Free memory using the appropriate deallocation method. For example,
 most backend memory is allocated using <CODE
CLASS="FUNCTION"
>palloc()</CODE
>, so use
 <CODE
CLASS="FUNCTION"
>pfree()</CODE
> to free it. Using C++
 <CODE
CLASS="FUNCTION"
>delete</CODE
> in such cases will fail.
 </LI
><LI
> Prevent exceptions from propagating into the C code (use a catch-all
 block at the top level of all <TT
CLASS="LITERAL"
>extern C</TT
> functions). This
 is necessary even if the C++ code does not explicitly throw any
 exceptions, because events like out-of-memory can still throw
 exceptions. Any exceptions must be caught and appropriate errors
 passed back to the C interface. If possible, compile C++ with
 <TT
CLASS="OPTION"
>-fno-exceptions</TT
> to eliminate exceptions entirely; in such
 cases, you must check for failures in your C++ code, e.g. check for
 NULL returned by <CODE
CLASS="FUNCTION"
>new()</CODE
>.
 </LI
><LI
> If calling backend functions from C++ code, be sure that the
 C++ call stack contains only plain old data structures
 (<ACRONYM
CLASS="ACRONYM"
>POD</ACRONYM
>). This is necessary because backend errors
 generate a distant <CODE
CLASS="FUNCTION"
>longjmp()</CODE
> that does not properly
 unroll a C++ call stack with non-POD objects.
 </LI
></UL
>
 In summary, it is best to place C++ code behind a wall of
 <TT
CLASS="LITERAL"
>extern C</TT
> functions that interface to the backend,
 and avoid exception, memory, and call stack leakage.
 </DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="xfunc-internal.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="xaggr.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Internal Functions</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="extend.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>User-defined Aggregates</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>

FILE FOLDER

Name	Size	Permission
LEGALNOTICE.html	2681 bytes	0644
acronyms.html	16284 bytes	0644
admin.html	12564 bytes	0644
adminpack.html	7889 bytes	0644
app-clusterdb.html	10602 bytes	0644
app-createdb.html	12856 bytes	0644
app-createlang.html	9907 bytes	0644
app-createuser.html	15640 bytes	0644
app-dropdb.html	9642 bytes	0644
app-droplang.html	9638 bytes	0644
app-dropuser.html	9596 bytes	0644
app-ecpg.html	8718 bytes	0644
app-initdb.html	15405 bytes	0644
app-pg-ctl.html	22459 bytes	0644
app-pg-dumpall.html	20706 bytes	0644
app-pgbasebackup.html	19833 bytes	0644
app-pgconfig.html	11093 bytes	0644
app-pgcontroldata.html	3979 bytes	0644
app-pgdump.html	43964 bytes	0644
app-pgreceivexlog.html	11057 bytes	0644
app-pgresetxlog.html	11566 bytes	0644
app-pgrestore.html	30269 bytes	0644
app-postgres.html	31828 bytes	0644
app-postmaster.html	3005 bytes	0644
app-psql.html	138871 bytes	0644
app-reindexdb.html	11281 bytes	0644
app-vacuumdb.html	12616 bytes	0644
appendixes.html	26329 bytes	0644
applevel-consistency.html	10315 bytes	0644
archive-recovery-settings.html	7338 bytes	0644
arrays.html	28079 bytes	0644
auth-delay.html	3780 bytes	0644
auth-methods.html	36202 bytes	0644
auth-pg-hba-conf.html	29759 bytes	0644
auth-username-maps.html	8597 bytes	0644
auto-explain.html	9887 bytes	0644
backup-dump.html	15927 bytes	0644
backup-file.html	7996 bytes	0644
backup.html	4485 bytes	0644
biblio.html	11549 bytes	0644
bki-commands.html	9646 bytes	0644
bki-example.html	3049 bytes	0644
bki-format.html	3463 bytes	0644
bki-structure.html	4320 bytes	0644
bki.html	4330 bytes	0644
bookindex.html	243165 bytes	0644
btree-gin.html	4600 bytes	0644
btree-gist.html	6884 bytes	0644
bug-reporting.html	18646 bytes	0644
catalog-pg-aggregate.html	5502 bytes	0644
catalog-pg-am.html	10547 bytes	0644
catalog-pg-amop.html	7593 bytes	0644
catalog-pg-amproc.html	4885 bytes	0644
catalog-pg-attrdef.html	4364 bytes	0644
catalog-pg-attribute.html	10287 bytes	0644
catalog-pg-auth-members.html	4255 bytes	0644
catalog-pg-authid.html	6815 bytes	0644
catalog-pg-cast.html	6955 bytes	0644
catalog-pg-class.html	12661 bytes	0644
catalog-pg-collation.html	5897 bytes	0644
catalog-pg-constraint.html	11579 bytes	0644
catalog-pg-conversion.html	4430 bytes	0644
catalog-pg-database.html	7027 bytes	0644
catalog-pg-db-role-setting.html	4068 bytes	0644
catalog-pg-default-acl.html	5267 bytes	0644
catalog-pg-depend.html	8635 bytes	0644
catalog-pg-description.html	4478 bytes	0644
catalog-pg-enum.html	4716 bytes	0644
catalog-pg-extension.html	5282 bytes	0644
catalog-pg-foreign-data-wrapper.html	4945 bytes	0644
catalog-pg-foreign-server.html	4688 bytes	0644
catalog-pg-foreign-table.html	4036 bytes	0644
catalog-pg-index.html	8868 bytes	0644
catalog-pg-inherits.html	3888 bytes	0644
catalog-pg-language.html	5952 bytes	0644
catalog-pg-largeobject-metadata.html	3630 bytes	0644
catalog-pg-largeobject.html	5154 bytes	0644
catalog-pg-namespace.html	3751 bytes	0644
catalog-pg-opclass.html	5863 bytes	0644
catalog-pg-operator.html	6645 bytes	0644
catalog-pg-opfamily.html	4811 bytes	0644
catalog-pg-pltemplate.html	5364 bytes	0644
catalog-pg-proc.html	13403 bytes	0644
catalog-pg-range.html	5182 bytes	0644
catalog-pg-rewrite.html	5391 bytes	0644
catalog-pg-seclabel.html	4515 bytes	0644
catalog-pg-shdepend.html	7043 bytes	0644
catalog-pg-shdescription.html	4247 bytes	0644
catalog-pg-shseclabel.html	4404 bytes	0644
catalog-pg-statistic.html	9538 bytes	0644
catalog-pg-tablespace.html	4158 bytes	0644
catalog-pg-trigger.html	8287 bytes	0644
catalog-pg-ts-config-map.html	4193 bytes	0644
catalog-pg-ts-config.html	4481 bytes	0644
catalog-pg-ts-dict.html	4716 bytes	0644
catalog-pg-ts-parser.html	5082 bytes	0644
catalog-pg-ts-template.html	4258 bytes	0644
catalog-pg-type.html	19905 bytes	0644
catalog-pg-user-mapping.html	3847 bytes	0644
catalogs-overview.html	10431 bytes	0644
catalogs.html	10387 bytes	0644
charset.html	4162 bytes	0644
chkpass.html	4391 bytes	0644
citext.html	11148 bytes	0644
client-authentication-problems.html	4224 bytes	0644
client-authentication.html	5914 bytes	0644
client-interfaces.html	13717 bytes	0644
collation.html	14222 bytes	0644
config-setting.html	11146 bytes	0644
connect-estab.html	4315 bytes	0644
continuous-archiving.html	49830 bytes	0644
contrib-dblink-build-sql-delete.html	5451 bytes	0644
contrib-dblink-build-sql-insert.html	6052 bytes	0644
contrib-dblink-build-sql-update.html	6281 bytes	0644
contrib-dblink-cancel-query.html	3820 bytes	0644
contrib-dblink-close.html	4650 bytes	0644
contrib-dblink-connect-u.html	4482 bytes	0644
contrib-dblink-connect.html	7325 bytes	0644
contrib-dblink-disconnect.html	3718 bytes	0644
contrib-dblink-error-message.html	3508 bytes	0644
contrib-dblink-exec.html	5466 bytes	0644
contrib-dblink-fetch.html	5979 bytes	0644
contrib-dblink-function.html	8630 bytes	0644
contrib-dblink-get-connections.html	3206 bytes	0644
contrib-dblink-get-notify.html	4168 bytes	0644
contrib-dblink-get-pkey.html	4498 bytes	0644
contrib-dblink-get-result.html	6959 bytes	0644
contrib-dblink-is-busy.html	3490 bytes	0644
contrib-dblink-open.html	5464 bytes	0644
contrib-dblink-send-query.html	4170 bytes	0644
contrib-prog-client.html	3434 bytes	0644
contrib-prog-server.html	3837 bytes	0644
contrib-prog.html	3320 bytes	0644
contrib-spi.html	11236 bytes	0644
contrib.html	8904 bytes	0644
creating-cluster.html	12465 bytes	0644
cube.html	15941 bytes	0644
database-roles.html	6092 bytes	0644
datatype-binary.html	12893 bytes	0644
datatype-bit.html	5096 bytes	0644
datatype-boolean.html	5267 bytes	0644
datatype-character.html	11893 bytes	0644
datatype-datetime.html	50763 bytes	0644
datatype-enum.html	6433 bytes	0644
datatype-geometric.html	12503 bytes	0644
datatype-json.html	3439 bytes	0644
datatype-money.html	5482 bytes	0644
datatype-net-types.html	10423 bytes	0644
datatype-numeric.html	22353 bytes	0644
datatype-oid.html	9686 bytes	0644
datatype-pseudo.html	7285 bytes	0644
datatype-textsearch.html	10033 bytes	0644
datatype-uuid.html	4560 bytes	0644
datatype-xml.html	11334 bytes	0644
datatype.html	16609 bytes	0644
datetime-appendix.html	3525 bytes	0644
datetime-config-files.html	8980 bytes	0644
datetime-input-rules.html	6763 bytes	0644
datetime-keywords.html	5096 bytes	0644
datetime-units-history.html	7634 bytes	0644
dblink.html	5322 bytes	0644
ddl-alter.html	10498 bytes	0644
ddl-basics.html	7816 bytes	0644
ddl-constraints.html	22790 bytes	0644
ddl-default.html	4540 bytes	0644
ddl-depend.html	6498 bytes	0644
ddl-foreign-data.html	4485 bytes	0644
ddl-inherit.html	15308 bytes	0644
ddl-others.html	3080 bytes	0644
ddl-partitioning.html	27763 bytes	0644
ddl-priv.html	6066 bytes	0644
ddl-schemas.html	18046 bytes	0644
ddl-system-columns.html	8049 bytes	0644
ddl.html	6382 bytes	0644
dict-int.html	4793 bytes	0644
dict-xsyn.html	6481 bytes	0644
different-replication-solutions.html	14793 bytes	0644
disk-full.html	3517 bytes	0644
disk-usage.html	5661 bytes	0644
diskusage.html	2668 bytes	0644
dml-delete.html	3565 bytes	0644
dml-insert.html	5801 bytes	0644
dml-returning.html	5104 bytes	0644
dml-update.html	5556 bytes	0644
dml.html	2944 bytes	0644
docguide-authoring.html	6757 bytes	0644
docguide-build.html	15280 bytes	0644
docguide-docbook.html	3853 bytes	0644
docguide-style.html	7429 bytes	0644
docguide-toolsets.html	20683 bytes	0644
docguide.html	3624 bytes	0644
dummy-seclabel.html	4358 bytes	0644
dynamic-trace.html	27234 bytes	0644
earthdistance.html	8806 bytes	0644
ecpg-commands.html	9527 bytes	0644
ecpg-concept.html	4979 bytes	0644
ecpg-connect.html	10826 bytes	0644
ecpg-cpp.html	9624 bytes	0644
ecpg-descriptors.html	34909 bytes	0644
ecpg-develop.html	7964 bytes	0644
ecpg-dynamic.html	6515 bytes	0644
ecpg-errors.html	25737 bytes	0644
ecpg-informix-compat.html	52760 bytes	0644
ecpg-library.html	5798 bytes	0644
ecpg-lo.html	5527 bytes	0644
ecpg-pgtypes.html	54457 bytes	0644
ecpg-preproc.html	8985 bytes	0644
ecpg-process.html	5386 bytes	0644
ecpg-sql-allocate-descriptor.html	3983 bytes	0644
ecpg-sql-commands.html	4698 bytes	0644
ecpg-sql-connect.html	9375 bytes	0644
ecpg-sql-deallocate-descriptor.html	3773 bytes	0644
ecpg-sql-declare.html	5397 bytes	0644
ecpg-sql-describe.html	4595 bytes	0644
ecpg-sql-disconnect.html	4733 bytes	0644
ecpg-sql-execute-immediate.html	3877 bytes	0644
ecpg-sql-get-descriptor.html	7709 bytes	0644
ecpg-sql-open.html	4642 bytes	0644
ecpg-sql-prepare.html	4177 bytes	0644
ecpg-sql-set-autocommit.html	3333 bytes	0644
ecpg-sql-set-connection.html	3929 bytes	0644
ecpg-sql-set-descriptor.html	5505 bytes	0644
ecpg-sql-type.html	5026 bytes	0644
ecpg-sql-var.html	3539 bytes	0644
ecpg-sql-whenever.html	4686 bytes	0644
ecpg-variables.html	40283 bytes	0644
ecpg.html	10344 bytes	0644
encryption-options.html	7495 bytes	0644
errcodes-appendix.html	36965 bytes	0644
error-message-reporting.html	14124 bytes	0644
error-style-guide.html	16769 bytes	0644
event-log-registration.html	4188 bytes	0644
executor.html	6612 bytes	0644
explicit-joins.html	11019 bytes	0644
explicit-locking.html	25073 bytes	0644
extend-extensions.html	32430 bytes	0644
extend-how.html	4552 bytes	0644
extend-pgxs.html	11761 bytes	0644
extend-type-system.html	10111 bytes	0644
extend.html	9982 bytes	0644
external-admin-tools.html	2722 bytes	0644
external-extensions.html	3263 bytes	0644
external-interfaces.html	5513 bytes	0644
external-pl.html	4670 bytes	0644
external-projects.html	3004 bytes	0644
fdw-callbacks.html	12905 bytes	0644
fdw-functions.html	4496 bytes	0644
fdw-helpers.html	5988 bytes	0644
fdw-planning.html	9845 bytes	0644
fdwhandler.html	3990 bytes	0644
features-sql-standard.html	39105 bytes	0644
features.html	7566 bytes	0644
file-fdw.html	7709 bytes	0644
functions-admin.html	50395 bytes	0644
functions-aggregate.html	21814 bytes	0644
functions-array.html	13521 bytes	0644
functions-binarystring.html	12588 bytes	0644
functions-bitstring.html	6786 bytes	0644
functions-comparison.html	10638 bytes	0644
functions-comparisons.html	13531 bytes	0644
functions-conditional.html	11007 bytes	0644
functions-datetime.html	48303 bytes	0644
functions-enum.html	5491 bytes	0644
functions-formatting.html	35401 bytes	0644
functions-geometry.html	20347 bytes	0644
functions-info.html	58658 bytes	0644
functions-json.html	3814 bytes	0644
functions-logical.html	4665 bytes	0644
functions-matching.html	75728 bytes	0644
functions-math.html	20401 bytes	0644
functions-net.html	13502 bytes	0644
functions-range.html	10857 bytes	0644
functions-sequence.html	12925 bytes	0644
functions-srf.html	8840 bytes	0644
functions-string.html	59052 bytes	0644
functions-subquery.html	16381 bytes	0644
functions-textsearch.html	20488 bytes	0644
functions-trigger.html	4548 bytes	0644
functions-window.html	12085 bytes	0644
functions-xml.html	32169 bytes	0644
functions.html	9939 bytes	0644
fuzzystrmatch.html	8061 bytes	0644
geqo-biblio.html	3459 bytes	0644
geqo-intro.html	4415 bytes	0644
geqo-intro2.html	5627 bytes	0644
geqo-pg-intro.html	8785 bytes	0644
geqo.html	3616 bytes	0644
gin-examples.html	3322 bytes	0644
gin-extensibility.html	14402 bytes	0644
gin-implementation.html	6564 bytes	0644
gin-intro.html	4662 bytes	0644
gin-limit.html	2817 bytes	0644
gin-tips.html	5713 bytes	0644
gin.html	2929 bytes	0644
gist-examples.html	3752 bytes	0644
gist-extensibility.html	24354 bytes	0644
gist-implementation.html	4101 bytes	0644
gist-intro.html	3616 bytes	0644
gist.html	2679 bytes	0644
git.html	4564 bytes	0644
high-availability.html	7698 bytes	0644
history.html	11918 bytes	0644
hot-standby.html	36045 bytes	0644
hstore.html	22629 bytes	0644
index-catalog.html	7996 bytes	0644
index-cost-estimation.html	9991 bytes	0644
index-functions.html	19114 bytes	0644
index-locking.html	8049 bytes	0644
index-scanning.html	10707 bytes	0644
index-unique-checks.html	9192 bytes	0644
index.html	8071 bytes	0644
indexam.html	5247 bytes	0644
indexes-bitmap-scans.html	6580 bytes	0644
indexes-collations.html	3640 bytes	0644
indexes-examine.html	7161 bytes	0644
indexes-expressional.html	4813 bytes	0644
indexes-intro.html	6313 bytes	0644
indexes-multicolumn.html	6298 bytes	0644
indexes-opclass.html	7336 bytes	0644
indexes-ordering.html	6480 bytes	0644
indexes-partial.html	11812 bytes	0644
indexes-types.html	10233 bytes	0644
indexes-unique.html	4002 bytes	0644
indexes.html	3619 bytes	0644
information-schema.html	11177 bytes	0644
infoschema-administrable-role-authorizations.html	3751 bytes	0644
infoschema-applicable-roles.html	3970 bytes	0644
infoschema-attributes.html	12807 bytes	0644
infoschema-character-sets.html	7050 bytes	0644
infoschema-check-constraint-routine-usage.html	4349 bytes	0644
infoschema-check-constraints.html	3876 bytes	0644
infoschema-collation-character-set-applicab.html	4425 bytes	0644
infoschema-collations.html	3885 bytes	0644
infoschema-column-domain-usage.html	4322 bytes	0644
infoschema-column-options.html	4109 bytes	0644
infoschema-column-privileges.html	5029 bytes	0644
infoschema-column-udt-usage.html	4583 bytes	0644
infoschema-columns.html	17625 bytes	0644
infoschema-constraint-column-usage.html	4873 bytes	0644
infoschema-constraint-table-usage.html	4774 bytes	0644
infoschema-data-type-privileges.html	5089 bytes	0644
infoschema-datatypes.html	4229 bytes	0644
infoschema-domain-constraints.html	4664 bytes	0644
infoschema-domain-udt-usage.html	4171 bytes	0644
infoschema-domains.html	11367 bytes	0644
infoschema-element-types.html	11374 bytes	0644
infoschema-enabled-roles.html	3780 bytes	0644
infoschema-foreign-data-wrapper-options.html	3910 bytes	0644
infoschema-foreign-data-wrappers.html	4227 bytes	0644
infoschema-foreign-server-options.html	3853 bytes	0644
infoschema-foreign-servers.html	4571 bytes	0644
infoschema-foreign-table-options.html	3974 bytes	0644
infoschema-foreign-tables.html	4072 bytes	0644
infoschema-information-schema-catalog-name.html	3357 bytes	0644
infoschema-key-column-usage.html	5185 bytes	0644
infoschema-parameters.html	10799 bytes	0644
infoschema-referential-constraints.html	5664 bytes	0644
infoschema-role-column-grants.html	5017 bytes	0644
infoschema-role-routine-grants.html	5360 bytes	0644
infoschema-role-table-grants.html	5427 bytes	0644
infoschema-role-udt-grants.html	4781 bytes	0644
infoschema-role-usage-grants.html	5010 bytes	0644
infoschema-routine-privileges.html	5032 bytes	0644
infoschema-routines.html	23052 bytes	0644
infoschema-schema.html	3180 bytes	0644
infoschema-schemata.html	4248 bytes	0644
infoschema-sequences.html	6111 bytes	0644
infoschema-sql-features.html	4708 bytes	0644
infoschema-sql-implementation-info.html	4503 bytes	0644
infoschema-sql-languages.html	5094 bytes	0644
infoschema-sql-packages.html	4178 bytes	0644
infoschema-sql-parts.html	4080 bytes	0644
infoschema-sql-sizing-profiles.html	4177 bytes	0644
infoschema-sql-sizing.html	4101 bytes	0644
infoschema-table-constraints.html	4914 bytes	0644
infoschema-table-privileges.html	5097 bytes	0644
infoschema-tables.html	5957 bytes	0644
infoschema-triggered-update-columns.html	4554 bytes	0644
infoschema-triggers.html	9447 bytes	0644
infoschema-udt-privileges.html	4509 bytes	0644
infoschema-usage-privileges.html	5512 bytes	0644
infoschema-user-defined-types.html	9753 bytes	0644
infoschema-user-mapping-options.html	4449 bytes	0644
infoschema-user-mappings.html	3833 bytes	0644
infoschema-view-column-usage.html	4728 bytes	0644
infoschema-view-routine-usage.html	4368 bytes	0644
infoschema-view-table-usage.html	4389 bytes	0644
infoschema-views.html	5529 bytes	0644
install-getsource.html	3574 bytes	0644
install-post.html	8076 bytes	0644
install-procedure.html	46527 bytes	0644
install-requirements.html	14481 bytes	0644
install-short.html	2870 bytes	0644
install-windows-full.html	19274 bytes	0644
install-windows-libpq.html	6283 bytes	0644
install-windows.html	6620 bytes	0644
installation-platform-notes.html	39380 bytes	0644
installation.html	4160 bytes	0644
intagg.html	6254 bytes	0644
intarray.html	13757 bytes	0644
internals.html	15638 bytes	0644
intro-whatis.html	4011 bytes	0644
isn.html	13356 bytes	0644
kernel-resources.html	37822 bytes	0644
largeobjects.html	4675 bytes	0644
libpq-async.html	21020 bytes	0644
libpq-build.html	6369 bytes	0644
libpq-cancel.html	6777 bytes	0644
libpq-connect.html	51248 bytes	0644
libpq-control.html	6280 bytes	0644
libpq-copy.html	22442 bytes	0644
libpq-envars.html	9820 bytes	0644
libpq-events.html	23093 bytes	0644
libpq-example.html	16024 bytes	0644
libpq-exec.html	64877 bytes	0644
libpq-fastpath.html	6124 bytes	0644
libpq-ldap.html	5506 bytes	0644
libpq-misc.html	13815 bytes	0644
libpq-notice-processing.html	6284 bytes	0644
libpq-notify.html	6715 bytes	0644
libpq-pgpass.html	4861 bytes	0644
libpq-pgservice.html	3905 bytes	0644
libpq-single-row-mode.html	6353 bytes	0644
libpq-ssl.html	19972 bytes	0644
libpq-status.html	17695 bytes	0644
libpq-threading.html	5544 bytes	0644
libpq.html	7918 bytes	0644
lo-examplesect.html	8696 bytes	0644
lo-funcs.html	4640 bytes	0644
lo-implementation.html	3353 bytes	0644
lo-interfaces.html	15155 bytes	0644
lo-intro.html	3206 bytes	0644
lo.html	6627 bytes	0644
locale.html	13691 bytes	0644
locking-indexes.html	4350 bytes	0644
log-shipping-alternative.html	11057 bytes	0644
logfile-maintenance.html	7143 bytes	0644
ltree.html	27295 bytes	0644
maintenance.html	5538 bytes	0644
manage-ag-config.html	3746 bytes	0644
manage-ag-createdb.html	6310 bytes	0644
manage-ag-dropdb.html	3605 bytes	0644
manage-ag-overview.html	5144 bytes	0644
manage-ag-tablespaces.html	9250 bytes	0644
manage-ag-templatedbs.html	8162 bytes	0644
managing-databases.html	3273 bytes	0644
monitoring-locks.html	3673 bytes	0644
monitoring-ps.html	6782 bytes	0644
monitoring-stats.html	58063 bytes	0644
monitoring.html	4458 bytes	0644
multibyte.html	31965 bytes	0644
mvcc-caveats.html	4077 bytes	0644
mvcc-intro.html	4552 bytes	0644
mvcc.html	4302 bytes	0644
nls-programmer.html	10078 bytes	0644
nls-translator.html	14522 bytes	0644
nls.html	3134 bytes	0644
non-durability.html	4484 bytes	0644
notation.html	4415 bytes	0644
oid2name.html	11962 bytes	0644
overview.html	4093 bytes	0644
pageinspect.html	8117 bytes	0644
parser-stage.html	8117 bytes	0644
passwordcheck.html	4788 bytes	0644
performance-tips.html	4501 bytes	0644
perm-functions.html	3338 bytes	0644
pgarchivecleanup.html	8999 bytes	0644
pgbench.html	30833 bytes	0644
pgbuffercache.html	7715 bytes	0644
pgcrypto.html	38804 bytes	0644
pgfreespacemap.html	5230 bytes	0644
pgrowlocks.html	6078 bytes	0644
pgstandby.html	15204 bytes	0644
pgstatstatements.html	16068 bytes	0644
pgstattuple.html	9449 bytes	0644
pgtestfsync.html	5254 bytes	0644
pgtesttiming.html	12476 bytes	0644
pgtrgm.html	12333 bytes	0644
pgupgrade.html	24737 bytes	0644
planner-optimizer.html	9396 bytes	0644
planner-stats-details.html	3276 bytes	0644
planner-stats-security.html	5556 bytes	0644
planner-stats.html	9058 bytes	0644
plhandler.html	13748 bytes	0644
plperl-builtins.html	18276 bytes	0644
plperl-data.html	2878 bytes	0644
plperl-funcs.html	13369 bytes	0644
plperl-global.html	5067 bytes	0644
plperl-triggers.html	6446 bytes	0644
plperl-trusted.html	6712 bytes	0644
plperl-under-the-hood.html	8991 bytes	0644
plperl.html	4930 bytes	0644
plpgsql-control-structures.html	46183 bytes	0644
plpgsql-cursors.html	25586 bytes	0644
plpgsql-declarations.html	21746 bytes	0644
plpgsql-development-tips.html	9511 bytes	0644
plpgsql-errors-and-messages.html	10094 bytes	0644
plpgsql-expressions.html	4662 bytes	0644
plpgsql-implementation.html	18043 bytes	0644
plpgsql-overview.html	9032 bytes	0644
plpgsql-porting.html	27094 bytes	0644
plpgsql-statements.html	32221 bytes	0644
plpgsql-structure.html	8329 bytes	0644
plpgsql-trigger.html	22322 bytes	0644
plpgsql.html	6965 bytes	0644
plpython-data.html	14648 bytes	0644
plpython-database.html	15413 bytes	0644
plpython-do.html	2771 bytes	0644
plpython-envar.html	3885 bytes	0644
plpython-funcs.html	5478 bytes	0644
plpython-python23.html	7207 bytes	0644
plpython-sharing.html	3032 bytes	0644
plpython-subtransaction.html	7888 bytes	0644
plpython-trigger.html	5069 bytes	0644
plpython-util.html	5104 bytes	0644
plpython.html	6067 bytes	0644
pltcl-data.html	2906 bytes	0644
pltcl-dbaccess.html	13902 bytes	0644
pltcl-functions.html	6177 bytes	0644
pltcl-global.html	5066 bytes	0644
pltcl-overview.html	5288 bytes	0644
pltcl-procnames.html	3222 bytes	0644
pltcl-trigger.html	9452 bytes	0644
pltcl-unknown.html	5075 bytes	0644
pltcl.html	3400 bytes	0644
populate.html	17114 bytes	0644
postgres-user.html	3314 bytes	0644
preface.html	5070 bytes	0644
preventing-server-spoofing.html	4604 bytes	0644
protocol-changes.html	6650 bytes	0644
protocol-error-fields.html	6131 bytes	0644
protocol-flow.html	46202 bytes	0644
protocol-message-formats.html	40844 bytes	0644
protocol-message-types.html	4933 bytes	0644
protocol-overview.html	9670 bytes	0644
protocol-replication.html	14666 bytes	0644
protocol.html	5652 bytes	0644
queries-limit.html	5335 bytes	0644
queries-order.html	7369 bytes	0644
queries-overview.html	5068 bytes	0644
queries-select-lists.html	9308 bytes	0644
queries-table-expressions.html	39874 bytes	0644
queries-union.html	5114 bytes	0644
queries-values.html	4930 bytes	0644
queries-with.html	20880 bytes	0644
queries.html	4418 bytes	0644
query-path.html	5470 bytes	0644
querytree.html	11136 bytes	0644
rangetypes.html	22735 bytes	0644
recovery-config.html	3550 bytes	0644
recovery-target-settings.html	7762 bytes	0644
reference-client.html	6102 bytes	0644
reference-server.html	3964 bytes	0644
reference.html	23162 bytes	0644
regress-coverage.html	3325 bytes	0644
regress-evaluation.html	12487 bytes	0644
regress-run.html	13710 bytes	0644
regress-variant.html	7177 bytes	0644
regress.html	4277 bytes	0644
release-0-01.html	2555 bytes	0644
release-0-02.html	4292 bytes	0644
release-0-03.html	7798 bytes	0644
release-1-0.html	4229 bytes	0644
release-1-01.html	9346 bytes	0644
release-1-02.html	6489 bytes	0644
release-1-09.html	2525 bytes	0644
release-6-0.html	7920 bytes	0644
release-6-1-1.html	3719 bytes	0644
release-6-1.html	9025 bytes	0644
release-6-2-1.html	4405 bytes	0644
release-6-2.html	8883 bytes	0644
release-6-3-1.html	4444 bytes	0644
release-6-3-2.html	4157 bytes	0644
release-6-3.html	16311 bytes	0644
release-6-4-1.html	4061 bytes	0644
release-6-4-2.html	2908 bytes	0644
release-6-4.html	14732 bytes	0644
release-6-5-1.html	3842 bytes	0644
release-6-5-2.html	4102 bytes	0644
release-6-5-3.html	3053 bytes	0644
release-6-5.html	17387 bytes	0644
release-7-0-1.html	3920 bytes	0644
release-7-0-2.html	2887 bytes	0644
release-7-0-3.html	4656 bytes	0644
release-7-0.html	23104 bytes	0644
release-7-1-1.html	3262 bytes	0644
release-7-1-2.html	2975 bytes	0644
release-7-1-3.html	3139 bytes	0644
release-7-1.html	13017 bytes	0644
release-7-2-1.html	4011 bytes	0644
release-7-2-2.html	3793 bytes	0644
release-7-2-3.html	3364 bytes	0644
release-7-2-4.html	3587 bytes	0644
release-7-2-5.html	3746 bytes	0644
release-7-2-6.html	3624 bytes	0644
release-7-2-7.html	3726 bytes	0644
release-7-2-8.html	3948 bytes	0644
release-7-2.html	27098 bytes	0644
release-7-3-1.html	4168 bytes	0644
release-7-3-10.html	7493 bytes	0644
release-7-3-11.html	4111 bytes	0644
release-7-3-12.html	3527 bytes	0644
release-7-3-13.html	4618 bytes	0644
release-7-3-14.html	3931 bytes	0644
release-7-3-15.html	6315 bytes	0644
release-7-3-16.html	3424 bytes	0644
release-7-3-17.html	3550 bytes	0644
release-7-3-18.html	3647 bytes	0644
release-7-3-19.html	3686 bytes	0644
release-7-3-2.html	5205 bytes	0644
release-7-3-20.html	3524 bytes	0644
release-7-3-21.html	6216 bytes	0644
release-7-3-3.html	10290 bytes	0644
release-7-3-4.html	3502 bytes	0644
release-7-3-5.html	4493 bytes	0644
release-7-3-6.html	4428 bytes	0644
release-7-3-7.html	3352 bytes	0644
release-7-3-8.html	3571 bytes	0644
release-7-3-9.html	4079 bytes	0644
release-7-3.html	33053 bytes	0644
release-7-4-1.html	7116 bytes	0644
release-7-4-10.html	3806 bytes	0644
release-7-4-11.html	4857 bytes	0644
release-7-4-12.html	4221 bytes	0644
release-7-4-13.html	6961 bytes	0644
release-7-4-14.html	3673 bytes	0644
release-7-4-15.html	4270 bytes	0644
release-7-4-16.html	3972 bytes	0644
release-7-4-17.html	4013 bytes	0644
release-7-4-18.html	3927 bytes	0644
release-7-4-19.html	7242 bytes	0644
release-7-4-2.html	8260 bytes	0644
release-7-4-20.html	6605 bytes	0644
release-7-4-21.html	3922 bytes	0644
release-7-4-22.html	4071 bytes	0644
release-7-4-23.html	4423 bytes	0644
release-7-4-24.html	4289 bytes	0644
release-7-4-25.html	4506 bytes	0644
release-7-4-26.html	5455 bytes	0644
release-7-4-27.html	5164 bytes	0644
release-7-4-28.html	5629 bytes	0644
release-7-4-29.html	6960 bytes	0644
release-7-4-3.html	4615 bytes	0644
release-7-4-30.html	6211 bytes	0644
release-7-4-4.html	4085 bytes	0644
release-7-4-5.html	3194 bytes	0644
release-7-4-6.html	4731 bytes	0644
release-7-4-7.html	4274 bytes	0644
release-7-4-8.html	10156 bytes	0644
release-7-4-9.html	5118 bytes	0644
release-7-4.html	57378 bytes	0644
release-8-0-1.html	4744 bytes	0644
release-8-0-10.html	4751 bytes	0644
release-8-0-11.html	3969 bytes	0644
release-8-0-12.html	3134 bytes	0644
release-8-0-13.html	4118 bytes	0644
release-8-0-14.html	4518 bytes	0644
release-8-0-15.html	9101 bytes	0644
release-8-0-16.html	8946 bytes	0644
release-8-0-17.html	3920 bytes	0644
release-8-0-18.html	5579 bytes	0644
release-8-0-19.html	4976 bytes	0644
release-8-0-2.html	9566 bytes	0644
release-8-0-20.html	4312 bytes	0644
release-8-0-21.html	4504 bytes	0644
release-8-0-22.html	6440 bytes	0644
release-8-0-23.html	6023 bytes	0644
release-8-0-24.html	7002 bytes	0644
release-8-0-25.html	7427 bytes	0644
release-8-0-26.html	8026 bytes	0644
release-8-0-3.html	7425 bytes	0644
release-8-0-4.html	6680 bytes	0644
release-8-0-5.html	4816 bytes	0644
release-8-0-6.html	5694 bytes	0644
release-8-0-7.html	5909 bytes	0644
release-8-0-8.html	7225 bytes	0644
release-8-0-9.html	4306 bytes	0644
release-8-0.html	66818 bytes	0644
release-8-1-1.html	5459 bytes	0644
release-8-1-10.html	4781 bytes	0644
release-8-1-11.html	9946 bytes	0644
release-8-1-12.html	9341 bytes	0644
release-8-1-13.html	4292 bytes	0644
release-8-1-14.html	6901 bytes	0644
release-8-1-15.html	6274 bytes	0644
release-8-1-16.html	5278 bytes	0644
release-8-1-17.html	6035 bytes	0644
release-8-1-18.html	6442 bytes	0644
release-8-1-19.html	6612 bytes	0644
release-8-1-2.html	6335 bytes	0644
release-8-1-20.html	7298 bytes	0644
release-8-1-21.html	7213 bytes	0644
release-8-1-22.html	8324 bytes	0644
release-8-1-23.html	7933 bytes	0644
release-8-1-3.html	7026 bytes	0644
release-8-1-4.html	8873 bytes	0644
release-8-1-5.html	5479 bytes	0644
release-8-1-6.html	5337 bytes	0644
release-8-1-7.html	4558 bytes	0644
release-8-1-8.html	3116 bytes	0644
release-8-1-9.html	4388 bytes	0644
release-8-1.html	62113 bytes	0644
release-8-2-1.html	5065 bytes	0644
release-8-2-10.html	8180 bytes	0644
release-8-2-11.html	7147 bytes	0644
release-8-2-12.html	6748 bytes	0644
release-8-2-13.html	7348 bytes	0644
release-8-2-14.html	7876 bytes	0644
release-8-2-15.html	8155 bytes	0644
release-8-2-16.html	9293 bytes	0644
release-8-2-17.html	8214 bytes	0644
release-8-2-18.html	10277 bytes	0644
release-8-2-19.html	8589 bytes	0644
release-8-2-2.html	5802 bytes	0644
release-8-2-20.html	6244 bytes	0644
release-8-2-21.html	5593 bytes	0644
release-8-2-22.html	9617 bytes	0644
release-8-2-23.html	9559 bytes	0644
release-8-2-3.html	3095 bytes	0644
release-8-2-4.html	5428 bytes	0644
release-8-2-5.html	5995 bytes	0644
release-8-2-6.html	10551 bytes	0644
release-8-2-7.html	9311 bytes	0644
release-8-2-8.html	7521 bytes	0644
release-8-2-9.html	4281 bytes	0644
release-8-2.html	69398 bytes	0644
release-8-3-1.html	10585 bytes	0644
release-8-3-10.html	10725 bytes	0644
release-8-3-11.html	8963 bytes	0644
release-8-3-12.html	12119 bytes	0644
release-8-3-13.html	9506 bytes	0644
release-8-3-14.html	6242 bytes	0644
release-8-3-15.html	6381 bytes	0644
release-8-3-16.html	11015 bytes	0644
release-8-3-17.html	10590 bytes	0644
release-8-3-18.html	11265 bytes	0644
release-8-3-19.html	8466 bytes	0644
release-8-3-2.html	12203 bytes	0644
release-8-3-20.html	9251 bytes	0644
release-8-3-21.html	5034 bytes	0644
release-8-3-22.html	10585 bytes	0644
release-8-3-23.html	6284 bytes	0644
release-8-3-3.html	4275 bytes	0644
release-8-3-4.html	11273 bytes	0644
release-8-3-5.html	8689 bytes	0644
release-8-3-6.html	9197 bytes	0644
release-8-3-7.html	9729 bytes	0644
release-8-3-8.html	9260 bytes	0644
release-8-3-9.html	10206 bytes	0644
release-8-3.html	69773 bytes	0644
release-8-4-1.html	9563 bytes	0644
release-8-4-10.html	11932 bytes	0644
release-8-4-11.html	13787 bytes	0644
release-8-4-12.html	9987 bytes	0644
release-8-4-13.html	9714 bytes	0644
release-8-4-14.html	5117 bytes	0644
release-8-4-15.html	10626 bytes	0644
release-8-4-16.html	7329 bytes	0644
release-8-4-17.html	9572 bytes	0644
release-8-4-18.html	7048 bytes	0644
release-8-4-19.html	7780 bytes	0644
release-8-4-2.html	15697 bytes	0644
release-8-4-20.html	16258 bytes	0644
release-8-4-21.html	5450 bytes	0644
release-8-4-22.html	11306 bytes	0644
release-8-4-3.html	13928 bytes	0644
release-8-4-4.html	10736 bytes	0644
release-8-4-5.html	15933 bytes	0644
release-8-4-6.html	10430 bytes	0644
release-8-4-7.html	6220 bytes	0644
release-8-4-8.html	8850 bytes	0644
release-8-4-9.html	14528 bytes	0644
release-8-4.html	87976 bytes	0644
release-9-0-1.html	5946 bytes	0644
release-9-0-10.html	5693 bytes	0644
release-9-0-11.html	12666 bytes	0644
release-9-0-12.html	8824 bytes	0644
release-9-0-13.html	11671 bytes	0644
release-9-0-14.html	8759 bytes	0644
release-9-0-15.html	9147 bytes	0644
release-9-0-16.html	17408 bytes	0644
release-9-0-17.html	6335 bytes	0644
release-9-0-18.html	11879 bytes	0644
release-9-0-19.html	26610 bytes	0644
release-9-0-2.html	13636 bytes	0644
release-9-0-20.html	15836 bytes	0644
release-9-0-21.html	5166 bytes	0644
release-9-0-22.html	4321 bytes	0644
release-9-0-23.html	16158 bytes	0644
release-9-0-3.html	7256 bytes	0644
release-9-0-4.html	11345 bytes	0644
release-9-0-5.html	17915 bytes	0644
release-9-0-6.html	13426 bytes	0644
release-9-0-7.html	18091 bytes	0644
release-9-0-8.html	10993 bytes	0644
release-9-0-9.html	11743 bytes	0644
release-9-0.html	96127 bytes	0644
release-9-1-1.html	3670 bytes	0644
release-9-1-10.html	10352 bytes	0644
release-9-1-11.html	9584 bytes	0644
release-9-1-12.html	18554 bytes	0644
release-9-1-13.html	6685 bytes	0644
release-9-1-14.html	13036 bytes	0644
release-9-1-15.html	28969 bytes	0644
release-9-1-16.html	19119 bytes	0644
release-9-1-17.html	4947 bytes	0644
release-9-1-18.html	4102 bytes	0644
release-9-1-19.html	17617 bytes	0644
release-9-1-2.html	21571 bytes	0644
release-9-1-20.html	17541 bytes	0644
release-9-1-21.html	7601 bytes	0644
release-9-1-22.html	7258 bytes	0644
release-9-1-23.html	12653 bytes	0644
release-9-1-24.html	8731 bytes	0644
release-9-1-3.html	21153 bytes	0644
release-9-1-4.html	16018 bytes	0644
release-9-1-5.html	14042 bytes	0644
release-9-1-6.html	9521 bytes	0644
release-9-1-7.html	14941 bytes	0644
release-9-1-8.html	10154 bytes	0644
release-9-1-9.html	12679 bytes	0644
release-9-1.html	78963 bytes	0644
release-9-2-1.html	7111 bytes	0644
release-9-2-10.html	32368 bytes	0644
release-9-2-11.html	20298 bytes	0644
release-9-2-12.html	5130 bytes	0644
release-9-2-13.html	4102 bytes	0644
release-9-2-14.html	18386 bytes	0644
release-9-2-15.html	18605 bytes	0644
release-9-2-16.html	7598 bytes	0644
release-9-2-17.html	8195 bytes	0644
release-9-2-18.html	12718 bytes	0644
release-9-2-19.html	10514 bytes	0644
release-9-2-2.html	23001 bytes	0644
release-9-2-20.html	13332 bytes	0644
release-9-2-21.html	14198 bytes	0644
release-9-2-22.html	15865 bytes	0644
release-9-2-23.html	8126 bytes	0644
release-9-2-24.html	7877 bytes	0644
release-9-2-3.html	13373 bytes	0644
release-9-2-4.html	14800 bytes	0644
release-9-2-5.html	12005 bytes	0644
release-9-2-6.html	11684 bytes	0644
release-9-2-7.html	20022 bytes	0644
release-9-2-8.html	7375 bytes	0644
release-9-2-9.html	15615 bytes	0644
release-9-2.html	79519 bytes	0644
release.html	22882 bytes	0644
resources.html	4226 bytes	0644
role-attributes.html	7855 bytes	0644
role-membership.html	8390 bytes	0644
role-removal.html	5303 bytes	0644
routine-reindex.html	3628 bytes	0644
routine-vacuuming.html	38023 bytes	0644
row-estimation-examples.html	20767 bytes	0644
rowtypes.html	23412 bytes	0644
rule-system.html	4117 bytes	0644
rules-privileges.html	11663 bytes	0644
rules-status.html	4512 bytes	0644
rules-triggers.html	9476 bytes	0644
rules-update.html	32615 bytes	0644
rules-views.html	26888 bytes	0644
rules.html	4948 bytes	0644
runtime-config-autovacuum.html	10974 bytes	0644
runtime-config-client.html	32815 bytes	0644
runtime-config-compatible.html	14827 bytes	0644
runtime-config-connection.html	23478 bytes	0644
runtime-config-custom.html	3548 bytes	0644
runtime-config-developer.html	14070 bytes	0644
runtime-config-error-handling.html	3570 bytes	0644
runtime-config-file-locations.html	6977 bytes	0644
runtime-config-locks.html	7634 bytes	0644
runtime-config-logging.html	45446 bytes	0644
runtime-config-preset.html	8710 bytes	0644
runtime-config-query.html	24950 bytes	0644
runtime-config-replication.html	18294 bytes	0644
runtime-config-resource.html	27901 bytes	0644
runtime-config-short.html	6683 bytes	0644
runtime-config-statistics.html	8616 bytes	0644
runtime-config-wal.html	27093 bytes	0644
runtime-config.html	8249 bytes	0644
runtime.html	5241 bytes	0644
seg.html	15470 bytes	0644
sepgsql.html	30829 bytes	0644
server-programming.html	9618 bytes	0644
server-shutdown.html	6469 bytes	0644
server-start.html	14217 bytes	0644
source-format.html	5133 bytes	0644
source.html	4071 bytes	0644
sourcerepo.html	3411 bytes	0644
spgist-examples.html	2703 bytes	0644
spgist-extensibility.html	31282 bytes	0644
spgist-implementation.html	8098 bytes	0644
spgist-intro.html	4323 bytes	0644
spgist.html	2966 bytes	0644
spi-examples.html	6217 bytes	0644
spi-interface-support.html	3770 bytes	0644
spi-interface.html	5998 bytes	0644
spi-memory.html	7089 bytes	0644
spi-realloc.html	3627 bytes	0644
spi-spi-connect.html	4052 bytes	0644
spi-spi-copytuple.html	3453 bytes	0644
spi-spi-cursor-close.html	3336 bytes	0644
spi-spi-cursor-fetch.html	4110 bytes	0644
spi-spi-cursor-find.html	3464 bytes	0644
spi-spi-cursor-move.html	3890 bytes	0644
spi-spi-cursor-open-with-args.html	6178 bytes	0644
spi-spi-cursor-open-with-paramlist.html	5035 bytes	0644
spi-spi-cursor-open.html	5732 bytes	0644
spi-spi-exec.html	3591 bytes	0644
spi-spi-execp.html	4866 bytes	0644
spi-spi-execute-plan-with-paramlist.html	4893 bytes	0644
spi-spi-execute-plan.html	5901 bytes	0644
spi-spi-execute-with-args.html	6221 bytes	0644
spi-spi-execute.html	12598 bytes	0644
spi-spi-finish.html	3655 bytes	0644
spi-spi-fname.html	3767 bytes	0644
spi-spi-fnumber.html	3936 bytes	0644
spi-spi-freeplan.html	3505 bytes	0644
spi-spi-freetuple.html	3277 bytes	0644
spi-spi-freetupletable.html	3628 bytes	0644
spi-spi-getargcount.html	3698 bytes	0644
spi-spi-getargtypeid.html	4141 bytes	0644
spi-spi-getbinval.html	4287 bytes	0644
spi-spi-getnspname.html	3467 bytes	0644
spi-spi-getrelname.html	3351 bytes	0644
spi-spi-gettype.html	3714 bytes	0644
spi-spi-gettypeid.html	3718 bytes	0644
spi-spi-getvalue.html	4166 bytes	0644
spi-spi-is-cursor-plan.html	4560 bytes	0644
spi-spi-keepplan.html	3884 bytes	0644
spi-spi-modifytuple.html	5631 bytes	0644
spi-spi-palloc.html	3157 bytes	0644
spi-spi-pfree.html	3275 bytes	0644
spi-spi-pop.html	2743 bytes	0644
spi-spi-prepare-cursor.html	5055 bytes	0644
spi-spi-prepare-params.html	4412 bytes	0644
spi-spi-prepare.html	7661 bytes	0644
spi-spi-push.html	3737 bytes	0644
spi-spi-returntuple.html	4097 bytes	0644
spi-spi-saveplan.html	4576 bytes	0644
spi-spi-scroll-cursor-fetch.html	4809 bytes	0644
spi-spi-scroll-cursor-move.html	4899 bytes	0644
spi-visibility.html	4152 bytes	0644
spi.html	10843 bytes	0644
sql-abort.html	4177 bytes	0644
sql-alteraggregate.html	6111 bytes	0644
sql-altercollation.html	5084 bytes	0644
sql-alterconversion.html	5170 bytes	0644
sql-alterdatabase.html	8778 bytes	0644
sql-alterdefaultprivileges.html	9407 bytes	0644
sql-alterdomain.html	11113 bytes	0644
sql-alterextension.html	11745 bytes	0644
sql-alterforeigndatawrapper.html	7378 bytes	0644
sql-alterforeigntable.html	12707 bytes	0644
sql-alterfunction.html	12845 bytes	0644
sql-altergroup.html	5239 bytes	0644
sql-alterindex.html	7655 bytes	0644
sql-alterlanguage.html	4022 bytes	0644
sql-alterlargeobject.html	3730 bytes	0644
sql-alteropclass.html	5114 bytes	0644
sql-alteroperator.html	5435 bytes	0644
sql-alteropfamily.html	13564 bytes	0644
sql-alterrole.html	13028 bytes	0644
sql-alterschema.html	4314 bytes	0644
sql-altersequence.html	13031 bytes	0644
sql-alterserver.html	5928 bytes	0644
sql-altertable.html	43543 bytes	0644
sql-altertablespace.html	5866 bytes	0644
sql-altertrigger.html	4647 bytes	0644
sql-altertsconfig.html	8126 bytes	0644
sql-altertsdictionary.html	6539 bytes	0644
sql-altertsparser.html	4257 bytes	0644
sql-altertstemplate.html	4223 bytes	0644
sql-altertype.html	11193 bytes	0644
sql-alteruser.html	4720 bytes	0644
sql-alterusermapping.html	5714 bytes	0644
sql-alterview.html	6969 bytes	0644
sql-analyze.html	10674 bytes	0644
sql-begin.html	6695 bytes	0644
sql-checkpoint.html	3758 bytes	0644
sql-close.html	4984 bytes	0644
sql-cluster.html	9404 bytes	0644
sql-commands.html	18810 bytes	0644
sql-comment.html	13799 bytes	0644
sql-commit-prepared.html	4516 bytes	0644
sql-commit.html	3992 bytes	0644
sql-copy.html	37443 bytes	0644
sql-createaggregate.html	13829 bytes	0644
sql-createcast.html	19632 bytes	0644
sql-createcollation.html	6739 bytes	0644
sql-createconversion.html	6538 bytes	0644
sql-createdatabase.html	12133 bytes	0644
sql-createdomain.html	8544 bytes	0644
sql-createextension.html	9083 bytes	0644
sql-createforeigndatawrapper.html	8059 bytes	0644
sql-createforeigntable.html	7718 bytes	0644
sql-createfunction.html	31076 bytes	0644
sql-creategroup.html	4012 bytes	0644
sql-createindex.html	25934 bytes	0644
sql-createlanguage.html	14888 bytes	0644
sql-createopclass.html	12676 bytes	0644
sql-createoperator.html	10688 bytes	0644
sql-createopfamily.html	5626 bytes	0644
sql-createrole.html	19325 bytes	0644
sql-createrule.html	12656 bytes	0644
sql-createschema.html	8319 bytes	0644
sql-createsequence.html	13862 bytes	0644
sql-createserver.html	6251 bytes	0644
sql-createtable.html	59172 bytes	0644
sql-createtableas.html	12772 bytes	0644
sql-createtablespace.html	6104 bytes	0644
sql-createtrigger.html	23175 bytes	0644
sql-createtsconfig.html	5352 bytes	0644
sql-createtsdictionary.html	5533 bytes	0644
sql-createtsparser.html	5947 bytes	0644
sql-createtstemplate.html	5437 bytes	0644
sql-createtype.html	39460 bytes	0644
sql-createuser.html	4524 bytes	0644
sql-createusermapping.html	5503 bytes	0644
sql-createview.html	10556 bytes	0644
sql-deallocate.html	3785 bytes	0644
sql-declare.html	15400 bytes	0644
sql-delete.html	11777 bytes	0644
sql-discard.html	4309 bytes	0644
sql-do.html	5204 bytes	0644
sql-drop-owned.html	5058 bytes	0644
sql-dropaggregate.html	4561 bytes	0644
sql-dropcast.html	4344 bytes	0644
sql-dropcollation.html	4409 bytes	0644
sql-dropconversion.html	4437 bytes	0644
sql-dropdatabase.html	4344 bytes	0644
sql-dropdomain.html	4257 bytes	0644
sql-dropextension.html	4785 bytes	0644
sql-dropforeigndatawrapper.html	4526 bytes	0644
sql-dropforeigntable.html	4560 bytes	0644
sql-dropfunction.html	5838 bytes	0644
sql-dropgroup.html	3047 bytes	0644
sql-dropindex.html	5182 bytes	0644
sql-droplanguage.html	4841 bytes	0644
sql-dropopclass.html	5678 bytes	0644
sql-dropoperator.html	5222 bytes	0644
sql-dropopfamily.html	5279 bytes	0644
sql-droprole.html	5158 bytes	0644
sql-droprule.html	4151 bytes	0644
sql-dropschema.html	4529 bytes	0644
sql-dropsequence.html	4367 bytes	0644
sql-dropserver.html	4265 bytes	0644
sql-droptable.html	5028 bytes	0644
sql-droptablespace.html	4585 bytes	0644
sql-droptrigger.html	4711 bytes	0644
sql-droptsconfig.html	4772 bytes	0644
sql-droptsdictionary.html	4689 bytes	0644
sql-droptsparser.html	4595 bytes	0644
sql-droptstemplate.html	4567 bytes	0644
sql-droptype.html	4463 bytes	0644
sql-dropuser.html	3181 bytes	0644
sql-dropusermapping.html	4679 bytes	0644
sql-dropview.html	4262 bytes	0644
sql-end.html	4157 bytes	0644
sql-execute.html	5073 bytes	0644
sql-explain.html	17094 bytes	0644
sql-expressions.html	47801 bytes	0644
sql-fetch.html	14251 bytes	0644
sql-grant.html	29245 bytes	0644
sql-insert.html	12860 bytes	0644
sql-keywords-appendix.html	106534 bytes	0644
sql-listen.html	5903 bytes	0644
sql-load.html	4207 bytes	0644
sql-lock.html	11869 bytes	0644
sql-move.html	4984 bytes	0644
sql-notify.html	10948 bytes	0644
sql-prepare-transaction.html	8640 bytes	0644
sql-prepare.html	9181 bytes	0644
sql-reassign-owned.html	5344 bytes	0644
sql-reindex.html	11103 bytes	0644
sql-release-savepoint.html	5005 bytes	0644
sql-reset.html	4993 bytes	0644
sql-revoke.html	14879 bytes	0644
sql-rollback-prepared.html	4627 bytes	0644
sql-rollback-to.html	6401 bytes	0644
sql-rollback.html	3996 bytes	0644
sql-savepoint.html	5605 bytes	0644
sql-security-label.html	8879 bytes	0644
sql-select.html	79544 bytes	0644
sql-selectinto.html	7634 bytes	0644
sql-set-constraints.html	7068 bytes	0644
sql-set-role.html	6915 bytes	0644
sql-set-session-authorization.html	6062 bytes	0644
sql-set-transaction.html	12696 bytes	0644
sql-set.html	12057 bytes	0644
sql-show.html	6851 bytes	0644
sql-start-transaction.html	4983 bytes	0644
sql-syntax-calling-funcs.html	8080 bytes	0644
sql-syntax-lexical.html	43370 bytes	0644
sql-syntax.html	5430 bytes	0644
sql-truncate.html	9364 bytes	0644
sql-unlisten.html	4923 bytes	0644
sql-update.html	15669 bytes	0644
sql-vacuum.html	10669 bytes	0644
sql-values.html	10640 bytes	0644
sql.html	13569 bytes	0644
ssh-tunnels.html	6263 bytes	0644
ssl-tcp.html	13477 bytes	0644
sslinfo.html	7594 bytes	0644
standby-settings.html	5427 bytes	0644
storage-file-layout.html	12936 bytes	0644
storage-fsm.html	3821 bytes	0644
storage-init.html	2760 bytes	0644
storage-page-layout.html	13891 bytes	0644
storage-toast.html	11478 bytes	0644
storage-vm.html	3540 bytes	0644
storage.html	2952 bytes	0644
stylesheet.css	1538 bytes	0644
supported-platforms.html	5042 bytes	0644
tablefunc.html	32193 bytes	0644
tcn.html	4974 bytes	0644
test-parser.html	4530 bytes	0644
textsearch-configuration.html	6257 bytes	0644
textsearch-controls.html	26966 bytes	0644
textsearch-debugging.html	17227 bytes	0644
textsearch-dictionaries.html	31261 bytes	0644
textsearch-features.html	21310 bytes	0644
textsearch-indexes.html	7387 bytes	0644
textsearch-intro.html	18453 bytes	0644
textsearch-limitations.html	3859 bytes	0644
textsearch-migration.html	5034 bytes	0644
textsearch-parsers.html	9210 bytes	0644
textsearch-psql.html	9345 bytes	0644
textsearch-tables.html	9750 bytes	0644
textsearch.html	5878 bytes	0644
transaction-iso.html	27240 bytes	0644
trigger-datachanges.html	5072 bytes	0644
trigger-definition.html	15507 bytes	0644
trigger-example.html	7749 bytes	0644
trigger-interface.html	10719 bytes	0644
triggers.html	3798 bytes	0644
tsearch2.html	9950 bytes	0644
tutorial-accessdb.html	7040 bytes	0644
tutorial-advanced-intro.html	3341 bytes	0644
tutorial-advanced.html	2856 bytes	0644
tutorial-agg.html	7594 bytes	0644
tutorial-arch.html	4852 bytes	0644
tutorial-concepts.html	3839 bytes	0644
tutorial-conclusion.html	2849 bytes	0644
tutorial-createdb.html	9200 bytes	0644
tutorial-delete.html	3517 bytes	0644
tutorial-fk.html	4422 bytes	0644
tutorial-inheritance.html	6137 bytes	0644
tutorial-install.html	4522 bytes	0644
tutorial-join.html	9685 bytes	0644
tutorial-populate.html	4839 bytes	0644
tutorial-select.html	8033 bytes	0644
tutorial-sql-intro.html	4904 bytes	0644
tutorial-sql.html	3060 bytes	0644
tutorial-start.html	2629 bytes	0644
tutorial-table.html	5704 bytes	0644
tutorial-transactions.html	9948 bytes	0644
tutorial-update.html	3159 bytes	0644
tutorial-views.html	3375 bytes	0644
tutorial-window.html	12481 bytes	0644
tutorial.html	5209 bytes	0644
typeconv-func.html	12170 bytes	0644
typeconv-oper.html	14907 bytes	0644
typeconv-overview.html	8301 bytes	0644
typeconv-query.html	5450 bytes	0644
typeconv-union-case.html	6612 bytes	0644
typeconv.html	3721 bytes	0644
unaccent.html	6742 bytes	0644
unsupported-features-sql-standard.html	35115 bytes	0644
upgrading.html	12795 bytes	0644
user-manag.html	3983 bytes	0644
using-explain.html	41824 bytes	0644
uuid-ossp.html	7228 bytes	0644
vacuumlo.html	7548 bytes	0644
view-pg-available-extension-versions.html	4642 bytes	0644
view-pg-available-extensions.html	3944 bytes	0644
view-pg-cursors.html	5669 bytes	0644
view-pg-group.html	3897 bytes	0644
view-pg-indexes.html	4155 bytes	0644
view-pg-locks.html	14444 bytes	0644
view-pg-prepared-statements.html	5060 bytes	0644
view-pg-prepared-xacts.html	4912 bytes	0644
view-pg-roles.html	6073 bytes	0644
view-pg-rules.html	3999 bytes	0644
view-pg-seclabels.html	5123 bytes	0644
view-pg-settings.html	10600 bytes	0644
view-pg-shadow.html	5381 bytes	0644
view-pg-stats.html	8887 bytes	0644
view-pg-tables.html	4836 bytes	0644
view-pg-timezone-abbrevs.html	3860 bytes	0644
view-pg-timezone-names.html	4177 bytes	0644
view-pg-user-mappings.html	5165 bytes	0644
view-pg-user.html	4517 bytes	0644
view-pg-views.html	3853 bytes	0644
views-overview.html	6542 bytes	0644
wal-async-commit.html	9016 bytes	0644
wal-configuration.html	14960 bytes	0644
wal-internals.html	6151 bytes	0644
wal-intro.html	5534 bytes	0644
wal-reliability.html	11479 bytes	0644
wal.html	2928 bytes	0644
warm-standby-failover.html	6102 bytes	0644
warm-standby.html	34646 bytes	0644
xaggr.html	9902 bytes	0644
xfunc-c.html	78520 bytes	0644
xfunc-internal.html	4004 bytes	0644
xfunc-overload.html	5911 bytes	0644
xfunc-pl.html	2991 bytes	0644
xfunc-sql.html	38027 bytes	0644
xfunc-volatility.html	9839 bytes	0644
xfunc.html	4518 bytes	0644
xindex.html	44593 bytes	0644
xml2.html	16900 bytes	0644
xoper-optimization.html	23144 bytes	0644
xoper.html	4835 bytes	0644
xplang-install.html	11127 bytes	0644
xplang.html	4235 bytes	0644
xtypes.html	12114 bytes	0644