doc/src/sgml/ref/create_opfamily.sgml

   1 <!--
   2 $PostgreSQL$
   3 PostgreSQL documentation
   4 -->
   5
   6 <refentry id="SQL-CREATEOPFAMILY">
   7  <refmeta>
   8   <refentrytitle id="sql-createopfamily-title">CREATE OPERATOR FAMILY</refentrytitle>
   9   <manvolnum>7</manvolnum>
  10   <refmiscinfo>SQL - Language Statements</refmiscinfo>
  11  </refmeta>
  12
  13  <refnamediv>
  14   <refname>CREATE OPERATOR FAMILY</refname>
  15   <refpurpose>define a new operator family</refpurpose>
  16  </refnamediv>
  17
  18  <indexterm zone="sql-createopfamily">
  19   <primary>CREATE OPERATOR FAMILY</primary>
  20  </indexterm>
  21
  22  <refsynopsisdiv>
  23 <synopsis>
  24 CREATE OPERATOR FAMILY <replaceable class="parameter">name</replaceable> USING <replaceable class="parameter">index_method</replaceable>
  25 </synopsis>
  26  </refsynopsisdiv>
  27
  28  <refsect1>
  29   <title>Description</title>
  30
  31   <para>
  32    <command>CREATE OPERATOR FAMILY</command> creates a new operator family.
  33    An operator family defines a collection of related operator classes,
  34    and perhaps some additional operators and support functions that are
  35    compatible with these operator classes but not essential for the
  36    functioning of any individual index.  (Operators and functions that
  37    are essential to indexes should be grouped within the relevant operator
  38    class, rather than being <quote>loose</> in the operator family.
  39    Typically, single-data-type operators are bound to operator classes,
  40    while cross-data-type operators can be loose in an operator family
  41    containing operator classes for both data types.)
  42   </para>
  43
  44   <para>
  45    The new operator family is initially empty.  It should be populated
  46    by issuing subsequent <command>CREATE OPERATOR CLASS</command> commands
  47    to add contained operator classes, and optionally
  48    <command>ALTER OPERATOR FAMILY</command> commands to add <quote>loose</>
  49    operators and their corresponding support functions.
  50   </para>
  51
  52   <para>
  53    If a schema name is given then the operator family is created in the
  54    specified schema.  Otherwise it is created in the current schema.
  55    Two operator families in the same schema can have the same name only if they
  56    are for different index methods.
  57   </para>
  58
  59   <para>
  60    The user who defines an operator family becomes its owner.  Presently,
  61    the creating user must be a superuser.  (This restriction is made because
  62    an erroneous operator family definition could confuse or even crash the
  63    server.)
  64   </para>
  65
  66   <para>
  67    Refer to <xref linkend="xindex"> for further information.
  68   </para>
  69  </refsect1>
  70
  71  <refsect1>
  72   <title>Parameters</title>
  73
  74   <variablelist>
  75    <varlistentry>
  76     <term><replaceable class="parameter">name</replaceable></term>
  77     <listitem>
  78      <para>
  79       The name of the operator family to be created.  The name can be
  80       schema-qualified.
  81      </para>
  82     </listitem>
  83    </varlistentry>
  84
  85    <varlistentry>
  86     <term><replaceable class="parameter">index_method</replaceable></term>
  87     <listitem>
  88      <para>
  89       The name of the index method this operator family is for.
  90      </para>
  91     </listitem>
  92    </varlistentry>
  93   </variablelist>
  94  </refsect1>
  95
  96  <refsect1>
  97   <title>Compatibility</title>
  98
  99   <para>
 100    <command>CREATE OPERATOR FAMILY</command> is a
 101    <productname>PostgreSQL</productname> extension.  There is no
 102    <command>CREATE OPERATOR FAMILY</command> statement in the SQL
 103    standard.
 104   </para>
 105  </refsect1>
 106
 107  <refsect1>
 108   <title>See Also</title>
 109
 110   <simplelist type="inline">
 111    <member><xref linkend="sql-alteropfamily" endterm="sql-alteropfamily-title"></member>
 112    <member><xref linkend="sql-dropopfamily" endterm="sql-dropopfamily-title"></member>
 113    <member><xref linkend="sql-createopclass" endterm="sql-createopclass-title"></member>
 114    <member><xref linkend="sql-alteropclass" endterm="sql-alteropclass-title"></member>
 115    <member><xref linkend="sql-dropopclass" endterm="sql-dropopclass-title"></member>
 116   </simplelist>
 117  </refsect1>
 118 </refentry>