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-rw-r--r--doc/src/sgml/ref/create_table.sgml19
1 files changed, 13 insertions, 6 deletions
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index c1b6beb..0301dff 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1108,10 +1108,11 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
column(s) of some row of the referenced table. If the <replaceable
class="parameter">refcolumn</replaceable> list is omitted, the
primary key of the <replaceable class="parameter">reftable</replaceable>
- is used. The referenced columns must be the columns of a non-deferrable
- unique or primary key constraint in the referenced table. The user
- must have <literal>REFERENCES</literal> permission on the referenced table
- (either the whole table, or the specific referenced columns). The
+ is used. Otherwise, the <replaceable class="parameter">refcolumn</replaceable>
+ list must refer to the columns of a non-deferrable unique or primary key
+ constraint or be the columns of a non-partial unique index. The user
+ must have <literal>REFERENCES</literal> permission on the referenced
+ table (either the whole table, or the specific referenced columns). The
addition of a foreign key constraint requires a
<literal>SHARE ROW EXCLUSIVE</literal> lock on the referenced table.
Note that foreign key constraints cannot be defined between temporary
@@ -2248,13 +2249,19 @@ CREATE TABLE cities_partdef
</refsect2>
<refsect2>
- <title>Foreign-Key Constraint Actions</title>
+ <title>Foreign Key Constraints</title>
<para>
- The ability to specify column lists in the foreign-key actions
+ The ability to specify column lists in the foreign key actions
<literal>SET DEFAULT</literal> and <literal>SET NULL</literal> is a
<productname>PostgreSQL</productname> extension.
</para>
+
+ <para>
+ It is a <productname>PostgreSQL</productname> extension that a
+ foreign key constraint may reference columns of a unique index instead of
+ columns of a primary key or unique constraint.
+ </para>
</refsect2>
<refsect2>