diff options
| -rw-r--r-- | doc/src/sgml/ddl.sgml | 24 | ||||
| -rw-r--r-- | doc/src/sgml/ref/alter_table.sgml | 2 |
2 files changed, 11 insertions, 15 deletions
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index b4648321dc4..63bc946c3b6 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -3915,18 +3915,25 @@ DROP TABLE measurement_y2006m02; <para> Another option that is often preferable is to remove the partition from the partitioned table but retain access to it as a table in its own - right: + right. This has two forms: <programlisting> ALTER TABLE measurement DETACH PARTITION measurement_y2006m02; +ALTER TABLE measurement DETACH PARTITION measurement_y2006m02 CONCURRENTLY; </programlisting> - This allows further operations to be performed on the data before + These allow further operations to be performed on the data before it is dropped. For example, this is often a useful time to back up the data using <command>COPY</command>, <application>pg_dump</application>, or similar tools. It might also be a useful time to aggregate data into smaller formats, perform other data manipulations, or run - reports. + reports. The first form of the command requires an + <literal>ACCESS EXCLUSIVE</literal> lock on the parent table. + Adding the <literal>CONCURRENTLY</literal> qualifier as in the second + form allows the detach operation to require only + <literal>SHARE UPDATE EXCLUSIVE</literal> lock on the parent table, but see + <link linkend="sql-altertable-detach-partition"><literal>ALTER TABLE ... DETACH PARTITION</literal></link> + for details on the restrictions. </para> <para> @@ -4163,17 +4170,6 @@ ALTER INDEX measurement_city_id_logdate_key might be poor.) </para> </listitem> - - <listitem> - <para> - Some operations require a stronger lock when using declarative - partitioning than when using table inheritance. For example, - removing a partition from a partitioned table requires taking - an <literal>ACCESS EXCLUSIVE</literal> lock on the parent table, - whereas a <literal>SHARE UPDATE EXCLUSIVE</literal> lock is enough - in the case of regular inheritance. - </para> - </listitem> </itemizedlist> </para> diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index 9cef1f101eb..087f640dc07 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -967,7 +967,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM </listitem> </varlistentry> - <varlistentry> + <varlistentry id="sql-altertable-detach-partition"> <term><literal>DETACH PARTITION <replaceable class="parameter">partition_name</replaceable> [ CONCURRENTLY | FINALIZE ]</literal></term> <listitem> |