operators associated with access method operator families.  There is one
   row for each operator that is a member of an operator family.  A family
   member can be either a <firstterm>search</firstterm> operator or an
   <firstterm>ordering</firstterm> operator.  An operator
   can appear in more than one family, but cannot appear in more than one
   search position nor more than one ordering position within a family.
   (It is allowed, though unlikely, for an operator to be used for both
   search and ordering purposes.)
  </para>

  <table>
   <title><structname>pg_amop</structname> Columns</title>
   <tgroup cols="1">
    <thead>
     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       Column Type
      </para>
      <para>
       Description
      </para></entry>
     </row>
    </thead>

    <tbody>
     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>oid</structfield> <type>oid</type>
      </para>
      <para>
       Row identifier
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>amopfamily</structfield> <type>oid</type>
       (references <link linkend="catalog-pg-opfamily"><structname>pg_opfamily</structname></link>.<structfield>oid</structfield>)
      </para>
      <para>
       The operator family this entry is for
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>amoplefttype</structfield> <type>oid</type>
       (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
      </para>
      <para>
       Left-hand input data type of operator
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>amoprighttype</structfield> <type>oid</type>
       (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
      </para>
      <para>
       Right-hand input data type of operator
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>amopstrategy</structfield> <type>int2</type>
      </para>
      <para>
       Operator strategy number
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>amoppurpose</structfield> <type>char</type>
      </para>
      <para>
       Operator purpose, either <literal>s</literal> for search or
       <literal>o</literal> for ordering
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>amopopr</structfield> <type>oid</type>
       (references <link linkend="catalog-pg-operator"><structname>pg_operator</structname></link>.<structfield>oid</structfield>)
      </para>
      <para>
       OID of the operator
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>amopmethod</structfield> <type>oid</type>
       (references <link linkend="catalog-pg-am"><structname>pg_am</structname></link>.<structfield>oid</structfield>)
      </para>
      <para>
       Index access method operator family is for
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>amopsortfamily</structfield> <type>oid</type>
       (references <link linkend="catalog-pg-opfamily"><structname>pg_opfamily</structname></link>.<structfield>oid</structfield>)
      </para>
      <para>
       The B-tree operator family this entry sorts according to, if an
       ordering operator; zero if a search operator
      </para></entry>
     </row>
    </tbody>
   </tgroup>