<para>

To build 64 bit binaries using MinGW, install the 64 bit tool set

from <ulink url="http://mingw-w64.sourceforge.net/"></ulink>, put its bin

directory in the <envar>PATH</envar>, and run

<command>configure</command> with the

directory in the <envar>PATH</envar>, and run

<command>configure</command> with the

<command>--host=x86_64-w64-mingw</command> option.

</para>

should execute this code and return.

</para>

<para>

It's recommended that you wrap all these function declarations,

as well as the <command>CREATE LANGUAGE</> command itself, into

an <firstterm>extension</> so that a simple <command>CREATE EXTENSION</>

command is sufficient to install the language. See

<xref linkend="extend-extensions"> for information about writing

extensions.

</para>

<para>

The procedural languages included in the standard distribution

are good references when trying to write your own language handler.

<para>

To install PL/Perl in a particular database, use

<literal>CREATE EXTENSION plperl</>, or from the shell command line use

<literal>createlang plperl <replaceable>dbname</></literal>.

</para>

<note>

<para>

Arguments will be converted from the database's encoding to UTF-8

for use inside plperl, and then converted from UTF-8 back to the

database encoding upon return.

Arguments will be converted from the database's encoding to UTF-8

for use inside plperl, and then converted from UTF-8 back to the

database encoding upon return.

</para>

</note>

mail. To handle these cases, PL/Perl can also be installed as an

<quote>untrusted</> language (usually called

<application>PL/PerlU</application><indexterm><primary>PL/PerlU</></indexterm>).

In this case the full Perl language is available. If the

<command>createlang</command> program is used to install the

In this case the full Perl language is available. When installing the

language, the language name <literal>plperlu</literal> will select

the untrusted PL/Perl variant.

</para>

<para>

To install PL/Python in a particular database, use

<literal>CREATE EXTENSION plpythonu</>, or from the shell command line use

<literal>createlang plpythonu <replaceable>dbname</></literal> (but

see also <xref linkend="plpython-python23">).

</para>

directory if Tcl support is specified in the configuration step of

the installation procedure. To install <application>PL/Tcl</>

and/or <application>PL/TclU</> in a particular database, use the

<command>CREATE EXTENSION</> command or the

<command>createlang</command> program, for example

<literal>createlang pltcl <replaceable>dbname</></literal> or

<literal>createlang pltclu <replaceable>dbname</></literal>.

defined in this new language.

</para>

<note>

<para>

As of <productname>PostgreSQL</productname> 9.1, most procedural

languages have been made into <quote>extensions</>, and should

therefore be installed with <xref linkend="sql-createextension">

not <command>CREATE LANGUAGE</command>. Direct use of

<command>CREATE LANGUAGE</command> should now be confined to

extension installation scripts. If you have a <quote>bare</>

language in your database, perhaps as a result of an upgrade,

you can convert it to an extension using

<literal>CREATE EXTENSION <replaceable>langname</> FROM

unpackaged</literal>.

</para>

</note>

<para>

<command>CREATE LANGUAGE</command> effectively associates the

language name with handler function(s) that are responsible for executing

previously registered procedural language. You must be a superuser

or the owner of the language to use <command>DROP LANGUAGE</>.

</para>

<note>

<para>

As of <productname>PostgreSQL</productname> 9.1, most procedural

languages have been made into <quote>extensions</>, and should

therefore be removed with <xref linkend="sql-dropextension">

not <command>DROP LANGUAGE</command>.

</para>

</note>

</refsect1>

<refsect1>

<para>

For the languages supplied with the standard distribution, it is

only necessary to execute <command>CREATELANGUAGE</>

only necessary to execute <command>CREATEEXTENSION</>

<replaceable>language_name</> to install the language into the

current database. Alternatively, the program <xref

linkend="app-createlang"> can be used to do this from the shell

createlang plperl template1

</programlisting>

The manual procedure described below is only recommended for

installing custom languages that <command>CREATE LANGUAGE</command>

does not know about.

installing languages that have not been packaged as extensions.

</para>

<procedure>

<para>

A procedural language is installed in a database in five steps,

which must be carried out by a database superuser.(For languages

which must be carried out by a database superuser.In most cases

</para>

<step performance="required" id="xplang-install-cr1">

CREATE FUNCTION <replaceable>validator_function_name</replaceable>(oid)

RETURNS void

AS '<replaceable>path-to-shared-object</replaceable>'

LANGUAGE C;

LANGUAGE C STRICT;

</synopsis>

</para>

</step>

<step performance="required" id="xplang-install-cr5">

<para>

The PL must be declared with the command

Finally, the PL must be declared with the command

<synopsis>

CREATE <optional>TRUSTED</optional> <optional>PROCEDURAL</optional> LANGUAGE <replaceable>language-name</replaceable>

HANDLER <replaceable>handler_function_name</replaceable>

the language does not grant access to data that the user would

not otherwise have. Trusted languages are designed for ordinary

database users (those without superuser privilege) and allows them

to safely createoffunctions and trigger

to safely create functions and trigger

procedures. Since PL functions are executed inside the database

server, the <literal>TRUSTED</literal> flag should only be given

for languages that do not allow access to database server

'$libdir/plperl' LANGUAGE C;

CREATE FUNCTION plperl_validator(oid) RETURNS void AS

'$libdir/plperl' LANGUAGE C;

'$libdir/plperl' LANGUAGE C STRICT;

</programlisting>

</para>