specified by the index method.
</para>
+ <para>
+ Additionally, some opclasses allow users to specify parameters which
+ control their behavior. Each builtin index access method has an optional
+ <function>options</function> support function, which defines a set of
+ opclass-specific parameters.
+ </para>
+
<para>
B-trees require a comparison support function,
- and allow three additional support functions to be
+ and allow four additional support functions to be
supplied at the operator class author's option, as shown in <xref
linkend="xindex-btree-support-table"/>.
The requirements for these support functions are explained further in
<xref linkend="btree-support-funcs"/>.
</para>
- <para>
- Additionally, some opclasses allow users to specify parameters which
- control their behavior. Each builtin index access method has an optional
- <function>options</function> support function, which defines a set of
- opclass-specific parameters.
- </para>
-
<table tocentry="1" id="xindex-btree-support-table">
<title>B-Tree Support Functions</title>
<tgroup cols="2">
</table>
<para>
- Hash indexes require one support function, and allow a second one to be
- supplied at the operator class author's option, as shown in <xref
+ Hash indexes require one support function, and allow two additional ones to
+ be supplied at the operator class author's option, as shown in <xref
linkend="xindex-hash-support-table"/>.
</para>
</table>
<para>
- GiST indexes have nine support functions, two of which are optional,
+ GiST indexes have ten support functions, three of which are optional,
as shown in <xref linkend="xindex-gist-support-table"/>.
(For more information see <xref linkend="gist"/>.)
</para>
</table>
<para>
- SP-GiST indexes require five support functions, as
+ SP-GiST indexes have six support functions, one of which is optional, as
shown in <xref linkend="xindex-spgist-support-table"/>.
(For more information see <xref linkend="spgist"/>.)
</para>
</table>
<para>
- GIN indexes have six support functions, three of which are optional,
+ GIN indexes have seven support functions, four of which are optional,
as shown in <xref linkend="xindex-gin-support-table"/>.
(For more information see <xref linkend="gin"/>.)
</para>
</table>
<para>
- BRIN indexes have four basic support functions, as shown in
- <xref linkend="xindex-brin-support-table"/>; those basic functions
- may require additional support functions to be provided.
+ BRIN indexes have five basic support functions, one of which is optional,
+ as shown in <xref linkend="xindex-brin-support-table"/>. Some versions of
+ the basic functions require additional support functions to be provided.
(For more information see <xref linkend="brin-extensibility"/>.)
</para>