diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/create_aggregate.sgml | 27 |
1 files changed, 18 insertions, 9 deletions
diff --git a/doc/src/sgml/ref/create_aggregate.sgml b/doc/src/sgml/ref/create_aggregate.sgml index b8cd2e7af90..ca0e9db8b13 100644 --- a/doc/src/sgml/ref/create_aggregate.sgml +++ b/doc/src/sgml/ref/create_aggregate.sgml @@ -21,7 +21,7 @@ PostgreSQL documentation <refsynopsisdiv> <synopsis> -CREATE AGGREGATE <replaceable class="parameter">name</replaceable> ( [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">arg_data_type</replaceable> [ , ... ] ) ( +CREATE [ OR REPLACE ] AGGREGATE <replaceable class="parameter">name</replaceable> ( [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">arg_data_type</replaceable> [ , ... ] ) ( SFUNC = <replaceable class="parameter">sfunc</replaceable>, STYPE = <replaceable class="parameter">state_data_type</replaceable> [ , SSPACE = <replaceable class="parameter">state_data_size</replaceable> ] @@ -44,7 +44,7 @@ CREATE AGGREGATE <replaceable class="parameter">name</replaceable> ( [ <replacea [ , PARALLEL = { SAFE | RESTRICTED | UNSAFE } ] ) -CREATE AGGREGATE <replaceable class="parameter">name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">arg_data_type</replaceable> [ , ... ] ] +CREATE [ OR REPLACE ] AGGREGATE <replaceable class="parameter">name</replaceable> ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">arg_data_type</replaceable> [ , ... ] ] ORDER BY [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">arg_data_type</replaceable> [ , ... ] ) ( SFUNC = <replaceable class="parameter">sfunc</replaceable>, STYPE = <replaceable class="parameter">state_data_type</replaceable> @@ -59,7 +59,7 @@ CREATE AGGREGATE <replaceable class="parameter">name</replaceable> ( [ [ <replac <phrase>or the old syntax</phrase> -CREATE AGGREGATE <replaceable class="parameter">name</replaceable> ( +CREATE [ OR REPLACE ] AGGREGATE <replaceable class="parameter">name</replaceable> ( BASETYPE = <replaceable class="parameter">base_type</replaceable>, SFUNC = <replaceable class="parameter">sfunc</replaceable>, STYPE = <replaceable class="parameter">state_data_type</replaceable> @@ -88,12 +88,21 @@ CREATE AGGREGATE <replaceable class="parameter">name</replaceable> ( <title>Description</title> <para> - <command>CREATE AGGREGATE</command> defines a new aggregate - function. Some basic and commonly-used aggregate functions are - included with the distribution; they are documented in <xref - linkend="functions-aggregate"/>. If one defines new types or needs - an aggregate function not already provided, then <command>CREATE - AGGREGATE</command> can be used to provide the desired features. + <command>CREATE AGGREGATE</command> defines a new aggregate function. + <command>CREATE OR REPLACE AGGREGATE</command> will either define a new + aggregate function or replace an existing definition. Some basic and + commonly-used aggregate functions are included with the distribution; they + are documented in <xref linkend="functions-aggregate"/>. If one defines new + types or needs an aggregate function not already provided, then + <command>CREATE AGGREGATE</command> can be used to provide the desired + features. + </para> + + <para> + When replacing an existing definition, the argument types, result type, + and number of direct arguments may not be changed. Also, the new definition + must be of the same kind (ordinary aggregate, ordered-set aggregate, or + hypothetical-set aggregate) as the old one. </para> <para> |