diff options
Diffstat (limited to 'doc/src/sgml/ref/create_opclass.sgml')
| -rw-r--r-- | doc/src/sgml/ref/create_opclass.sgml | 48 |
1 files changed, 42 insertions, 6 deletions
diff --git a/doc/src/sgml/ref/create_opclass.sgml b/doc/src/sgml/ref/create_opclass.sgml index 524be85f978..85a31e3b195 100644 --- a/doc/src/sgml/ref/create_opclass.sgml +++ b/doc/src/sgml/ref/create_opclass.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/create_opclass.sgml,v 1.18 2006/10/16 17:28:03 momjian Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/create_opclass.sgml,v 1.19 2007/01/23 05:07:17 tgl Exp $ PostgreSQL documentation --> @@ -20,9 +20,10 @@ PostgreSQL documentation <refsynopsisdiv> <synopsis> -CREATE OPERATOR CLASS <replaceable class="parameter">name</replaceable> [ DEFAULT ] FOR TYPE <replaceable class="parameter">data_type</replaceable> USING <replaceable class="parameter">index_method</replaceable> AS +CREATE OPERATOR CLASS <replaceable class="parameter">name</replaceable> [ DEFAULT ] FOR TYPE <replaceable class="parameter">data_type</replaceable> + USING <replaceable class="parameter">index_method</replaceable> [ FAMILY <replaceable class="parameter">family_name</replaceable> ] AS { OPERATOR <replaceable class="parameter">strategy_number</replaceable> <replaceable class="parameter">operator_name</replaceable> [ ( <replaceable class="parameter">op_type</replaceable>, <replaceable class="parameter">op_type</replaceable> ) ] [ RECHECK ] - | FUNCTION <replaceable class="parameter">support_number</replaceable> <replaceable class="parameter">funcname</replaceable> ( <replaceable class="parameter">argument_type</replaceable> [, ...] ) + | FUNCTION <replaceable class="parameter">support_number</replaceable> [ ( <replaceable class="parameter">op_type</replaceable> [ , <replaceable class="parameter">op_type</replaceable> ] ) ] <replaceable class="parameter">funcname</replaceable> ( <replaceable class="parameter">argument_type</replaceable> [, ...] ) | STORAGE <replaceable class="parameter">storage_type</replaceable> } [, ... ] </synopsis> @@ -40,7 +41,7 @@ CREATE OPERATOR CLASS <replaceable class="parameter">name</replaceable> [ DEFAUL be used by the index method when the operator class is selected for an index column. All the operators and functions used by an operator - class must be defined before the operator class is created. + class must be defined before the operator class can be created. </para> <para> @@ -66,6 +67,15 @@ CREATE OPERATOR CLASS <replaceable class="parameter">name</replaceable> [ DEFAUL </para> <para> + Related operator classes can be grouped into <firstterm>operator + families</>. To add a new operator class to an existing family, + specify the <literal>FAMILY</> option in <command>CREATE OPERATOR + CLASS</command>. Without this option, the new class is placed into + a family named the same as the new class (creating that family if + it doesn't already exist). + </para> + + <para> Refer to <xref linkend="xindex"> for further information. </para> </refsect1> @@ -114,6 +124,17 @@ CREATE OPERATOR CLASS <replaceable class="parameter">name</replaceable> [ DEFAUL </varlistentry> <varlistentry> + <term><replaceable class="parameter">family_name</replaceable></term> + <listitem> + <para> + The name of the existing operator family to add this operator class to. + If not specified, a family named the same as the operator class is + used (creating it, if it doesn't already exist). + </para> + </listitem> + </varlistentry> + + <varlistentry> <term><replaceable class="parameter">strategy_number</replaceable></term> <listitem> <para> @@ -137,11 +158,24 @@ CREATE OPERATOR CLASS <replaceable class="parameter">name</replaceable> [ DEFAUL <term><replaceable class="parameter">op_type</replaceable></term> <listitem> <para> - The operand data type(s) of an operator, or <literal>NONE</> to + In an <literal>OPERATOR</> clause, + the operand data type(s) of the operator, or <literal>NONE</> to signify a left-unary or right-unary operator. The operand data types may be omitted in the normal case where they are the same as the operator class's data type. </para> + + <para> + In a <literal>FUNCTION</> clause, the operand data type(s) the + function is intended to support, if different from + the input data type(s) of the function (for B-tree and hash indexes) + or the class's data type (for GIN and GiST indexes). These defaults + are always correct, so there is no point in specifying <replaceable + class="parameter">op_type</replaceable> in a <literal>FUNCTION</> clause + in <command>CREATE OPERATOR CLASS</>, but the option is provided + for consistency with the comparable syntax in + <command>ALTER OPERATOR FAMILY</>. + </para> </listitem> </varlistentry> @@ -192,7 +226,7 @@ CREATE OPERATOR CLASS <replaceable class="parameter">name</replaceable> [ DEFAUL <para> The data type actually stored in the index. Normally this is the same as the column data type, but some index methods - (GIN and GiST for now) allow it to be different. The + (currently GIN and GiST) allow it to be different. The <literal>STORAGE</> clause must be omitted unless the index method allows a different type to be used. </para> @@ -268,6 +302,8 @@ CREATE OPERATOR CLASS gist__int_ops <simplelist type="inline"> <member><xref linkend="sql-alteropclass" endterm="sql-alteropclass-title"></member> <member><xref linkend="sql-dropopclass" endterm="sql-dropopclass-title"></member> + <member><xref linkend="sql-createopfamily" endterm="sql-createopfamily-title"></member> + <member><xref linkend="sql-alteropfamily" endterm="sql-alteropfamily-title"></member> </simplelist> </refsect1> </refentry> |