</para>

<para>

In addition, any range type that is meant to be used with GiST indexes

In addition, any range type that is meant to be used with GiSTor SP-GiSTindexes

should define a subtype difference, or <literal>subtype_diff</>, function.

(A GiST index will still work without <literal>subtype_diff</>, but it is

(the index will still work without <literal>subtype_diff</>, but it is

likely to be considerably less efficient than if a difference function is

provided.) The subtype difference function takes two input values of the

subtype, and returns their difference (i.e., <replaceable>X</> minus

</para>

</sect2>

<sect2 id="rangetypes-gist">

<sect2 id="rangetypes-indexing">

<title>Indexing</title>

<indexterm>

</indexterm>

<para>

GiST indexes can be created for table columns of range types.

For instance:

GiSTand SP-GiSTindexes can be created for table columns of range types.

For instance, to create a GiST index:

<programlisting>

CREATE INDEX reservation_idx ON reservation USING gist (during);

</programlisting>

A GiST index can accelerate queries involving these range operators:

A GiSTor SP-GiSTindex can accelerate queries involving these range operators:

<literal>=</>,

<literal>&amp;&amp;</>,

<literal>&lt;@</>,