<phrase><replaceable class="parameter">exclude_element</replaceable> in an <literal>EXCLUDE</literal> constraint is:</phrase>
-{ <replaceable class="parameter">column_name</replaceable> | ( <replaceable class="parameter">expression</replaceable> ) } [ <replaceable class="parameter">opclass</replaceable> ] [ ASC | DESC ] [ NULLS { FIRST | LAST } ]
+{ <replaceable class="parameter">column_name</replaceable> | ( <replaceable class="parameter">expression</replaceable> ) } [ COLLATE <replaceable class="parameter">collation</replaceable> ] [ <replaceable class="parameter">opclass</replaceable> [ ( <replaceable class="parameter">opclass_parameter</replaceable> = <replaceable class="parameter">value</replaceable> [, ... ] ) ] ] [ ASC | DESC ] [ NULLS { FIRST | LAST } ]
<phrase><replaceable class="parameter">referential_action</replaceable> in a <literal>FOREIGN KEY</literal>/<literal>REFERENCES</literal> constraint is:</phrase>
<phrase><replaceable class="parameter">exclude_element</replaceable> in an <literal>EXCLUDE</literal> constraint is:</phrase>
-{ <replaceable class="parameter">column_name</replaceable> | ( <replaceable class="parameter">expression</replaceable> ) } [ <replaceable class="parameter">opclass</replaceable> ] [ ASC | DESC ] [ NULLS { FIRST | LAST } ]
+{ <replaceable class="parameter">column_name</replaceable> | ( <replaceable class="parameter">expression</replaceable> ) } [ COLLATE <replaceable class="parameter">collation</replaceable> ] [ <replaceable class="parameter">opclass</replaceable> [ ( <replaceable class="parameter">opclass_parameter</replaceable> = <replaceable class="parameter">value</replaceable> [, ... ] ) ] ] [ ASC | DESC ] [ NULLS { FIRST | LAST } ]
<phrase><replaceable class="parameter">referential_action</replaceable> in a <literal>FOREIGN KEY</literal>/<literal>REFERENCES</literal> constraint is:</phrase>
no two rows in the table contain overlapping circles
(see <xref linkend="datatype-geometric"/>) by using the
<literal>&&</literal> operator.
+ The operator(s) are required to be commutative.
</para>
<para>
operator must be associated with an appropriate operator class
(see <xref linkend="indexes-opclass"/>) for the index access
method <replaceable>index_method</replaceable>.
- The operators are required to be commutative.
Each <replaceable class="parameter">exclude_element</replaceable>
- can optionally specify an operator class and/or ordering options;
- these are described fully under
- <xref linkend="sql-createindex"/>.
+ defines a column of the index, so it can optionally specify a collation,
+ an operator class, operator class parameters, and/or ordering options;
+ these are described fully under <xref linkend="sql-createindex"/>.
</para>
<para>