diff options
Diffstat (limited to 'doc/src/sgml/ref/create_table.sgml')
| -rw-r--r-- | doc/src/sgml/ref/create_table.sgml | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index 43127940e41..a538283d8ec 100644 --- a/doc/src/sgml/ref/create_table.sgml +++ b/doc/src/sgml/ref/create_table.sgml @@ -1098,10 +1098,11 @@ 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 @@ -2234,6 +2235,16 @@ CREATE TABLE cities_partdef </refsect2> <refsect2> + <title>Foreign Key Constraints</title> + + <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> <title><literal>NULL</literal> <quote>Constraint</quote></title> <para> |