Restructure CREATE FUNCTION "NOTES" section to be shorter; move items
into proper sections, per suggestion from Tom.
This commit is contained in:
Bruce Momjian
parent
77e0d7b3eb
commit
d859b17f0f
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@ -1,5 +1,5 @@
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<!--
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$PostgreSQL: pgsql/doc/src/sgml/ref/create_function.sgml,v 1.91 2010/02/25 22:24:00 momjian Exp $
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$PostgreSQL: pgsql/doc/src/sgml/ref/create_function.sgml,v 1.92 2010/03/03 03:14:08 momjian Exp $
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-->
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<refentry id="SQL-CREATEFUNCTION">
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@ -46,6 +46,10 @@ CREATE [ OR REPLACE ] FUNCTION
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<command>CREATE FUNCTION</command> defines a new function.
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<command>CREATE OR REPLACE FUNCTION</command> will either create a
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new function, or replace an existing definition.
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To be able to define a function, the user must have the
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<literal>USAGE</literal> privilege on the language.
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</para>
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</para>
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<para>
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@ -69,6 +73,14 @@ CREATE [ OR REPLACE ] FUNCTION
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<literal>OUT</> parameters except by dropping the function.)
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</para>
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<para>
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When <command>CREATE OR REPLACE FUNCTION</> is used to replace an
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existing function, the ownership and permissions of the function
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do not change. All other function properties are assigned the
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values specified or implied in the command. You must own the function
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to replace it (this includes being a member of the owning role).
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</para>
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<para>
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If you drop and then recreate a function, the new function is not
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the same entity as the old; you will have to drop existing rules, views,
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@ -400,6 +412,18 @@ CREATE [ OR REPLACE ] FUNCTION
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the parameter as the value to be applied when the function is entered.
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</para>
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<para>
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If a <literal>SET</> clause is attached to a function, then
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the effects of a <command>SET LOCAL</> command executed inside the
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function for the same variable are restricted to the function: the
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configuration parameter's prior value is still restored at function exit.
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However, an ordinary
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<command>SET</> command (without <literal>LOCAL</>) overrides the
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<literal>SET</> clause, much as it would do for a previous <command>SET
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LOCAL</> command: the effects of such a command will persist after
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function exit, unless the current transaction is rolled back.
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</para>
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<para>
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See <xref linkend="sql-set" endterm="sql-set-title"> and
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<xref linkend="runtime-config">
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@ -417,6 +441,15 @@ CREATE [ OR REPLACE ] FUNCTION
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language. It can be an internal function name, the path to an
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object file, an SQL command, or text in a procedural language.
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</para>
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<para>
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It is often helpful to use dollar quoting (see <xref
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linkend="sql-syntax-dollar-quoting">) to write the function definition
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string, rather than the normal single quote syntax. Without dollar
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quoting, any single quotes or backslashes in the function definition must
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be escaped by doubling them.
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</para>
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</listitem>
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</varlistentry>
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@ -436,6 +469,14 @@ CREATE [ OR REPLACE ] FUNCTION
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language source code. If the link symbol is omitted, it is assumed
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to be the same as the name of the SQL function being defined.
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</para>
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<para>
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When repeated <command>CREATE FUNCTION</command> calls refer to
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the same object file, the file is only loaded once per session.
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To unload and
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reload the file (perhaps during development), start a new session.
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</para>
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</listitem>
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</varlistentry>
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@ -479,23 +520,13 @@ CREATE [ OR REPLACE ] FUNCTION
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</refsect1>
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<refsect1 id="sql-createfunction-notes">
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<title>Notes</title>
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<para>
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Refer to <xref linkend="xfunc"> for further information on writing
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functions.
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</para>
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<para>
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Refer to <xref linkend="xfunc"> for further information on writing
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functions.
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</para>
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<para>
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The full <acronym>SQL</acronym> type syntax is allowed for
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input arguments and return value. However, some details of the
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type specification (e.g., the precision field for
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type <type>numeric</type>) are the responsibility of the
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underlying function implementation and are silently swallowed
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(i.e., not recognized or
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enforced) by the <command>CREATE FUNCTION</command> command.
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</para>
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<refsect1 id="sql-createfunction-overloading">
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<title>Overloading</title>
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<para>
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<productname>PostgreSQL</productname> allows function
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@ -529,50 +560,19 @@ CREATE FUNCTION foo(int, int default 42) ...
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function should be called.
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</para>
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<para>
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When repeated <command>CREATE FUNCTION</command> calls refer to
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the same object file, the file is only loaded once per session.
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To unload and
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reload the file (perhaps during development), start a new session.
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</para>
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</refsect1>
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<refsect1 id="sql-createfunction-notes">
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<title>Notes</title>
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<para>
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Use <xref linkend="sql-dropfunction"
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endterm="sql-dropfunction-title"> to remove user-defined
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functions.
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</para>
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<para>
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It is often helpful to use dollar quoting (see <xref
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linkend="sql-syntax-dollar-quoting">) to write the function definition
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string, rather than the normal single quote syntax. Without dollar
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quoting, any single quotes or backslashes in the function definition must
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be escaped by doubling them.
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</para>
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<para>
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If a <literal>SET</> clause is attached to a function, then
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the effects of a <command>SET LOCAL</> command executed inside the
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function for the same variable are restricted to the function: the
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configuration parameter's prior value is still restored at function exit.
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However, an ordinary
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<command>SET</> command (without <literal>LOCAL</>) overrides the
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<literal>SET</> clause, much as it would do for a previous <command>SET
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LOCAL</> command: the effects of such a command will persist after
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function exit, unless the current transaction is rolled back.
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</para>
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<para>
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To be able to define a function, the user must have the
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<literal>USAGE</literal> privilege on the language.
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</para>
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<para>
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When <command>CREATE OR REPLACE FUNCTION</> is used to replace an
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existing function, the ownership and permissions of the function
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do not change. All other function properties are assigned the
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values specified or implied in the command. You must own the function
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to replace it (this includes being a member of the owning role).
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The full <acronym>SQL</acronym> type syntax is allowed for
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input arguments and return value. However, some details of the
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type specification (e.g., the precision field for
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type <type>numeric</type>) are the responsibility of the
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underlying function implementation and are silently swallowed
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(i.e., not recognized or
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enforced) by the <command>CREATE FUNCTION</command> command.
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</para>
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<para>
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|
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