diff options
Diffstat (limited to 'doc/src/sgml/ddl.sgml')
| -rw-r--r-- | doc/src/sgml/ddl.sgml | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index 570a003e4a9..1c56f162de3 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -546,7 +546,7 @@ CREATE TABLE products ( <para> Adding a unique constraint will automatically create a unique btree - index on the column or group of columns used in the constraint. + index on the column or group of columns used in the constraint. A uniqueness constraint on only some rows can be enforced by creating a <link linkend="indexes-partial">partial index</link>. </para> @@ -2409,6 +2409,17 @@ WHERE c.altitude > 500 AND c.tableoid = p.oid; </para> <para> + Another way to get the same effect is to use the <type>regclass</> + pseudo-type, which will print the table OID symbolically: + +<programlisting> +SELECT c.tableoid::regclass, c.name, c.altitude +FROM cities c +WHERE c.altitude > 500; +</programlisting> + </para> + + <para> Inheritance does not automatically propagate data from <command>INSERT</command> or <command>COPY</command> commands to other tables in the inheritance hierarchy. In our example, the @@ -2503,6 +2514,14 @@ VALUES ('Albany', NULL, NULL, 'NY'); further privileges to be granted. </para> + <para> + Foreign tables (see <xref linkend="ddl-foreign-data">) can also + be part of inheritance hierarchies, either as parent or child + tables, just as regular tables can be. If a foreign table is part + of an inheritance hierarchy then any operations not supported by + the foreign table are not supported on the whole hierarchy either. + </para> + <sect2 id="ddl-inherit-caveats"> <title>Caveats</title> @@ -2714,7 +2733,8 @@ VALUES ('Albany', NULL, NULL, 'NY'); <para> We will refer to the child tables as partitions, though they - are in every way normal <productname>PostgreSQL</> tables. + are in every way normal <productname>PostgreSQL</> tables + (or, possibly, foreign tables). </para> </listitem> |