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Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/logical-replication.sgml | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/doc/src/sgml/logical-replication.sgml b/doc/src/sgml/logical-replication.sgml index 92ec175af1..fa8ae536d9 100644 --- a/doc/src/sgml/logical-replication.sgml +++ b/doc/src/sgml/logical-replication.sgml @@ -110,11 +110,29 @@ Publications can choose to limit the changes they produce to any combination of <command>INSERT</command>, <command>UPDATE</command>, and <command>DELETE</command>, similar to how triggers are fired by - particular event types. If a table without a <literal>REPLICA - IDENTITY</literal> is added to a publication that - replicates <command>UPDATE</command> or <command>DELETE</command> - operations then subsequent <command>UPDATE</command> - or <command>DELETE</command> operations will fail on the publisher. + particular event types. By default, all operation types are replicated. + </para> + + <para> + A published table must have a <quote>replica identity</quote> configured in + order to be able to replicate <command>UPDATE</command> + and <command>DELETE</command> operations, so that appropriate rows to + update or delete can be identified on the subscriber side. By default, + this is the primary key, if there is one. Another unique index (with + certain additional requirements) can also be set to be the replica + identity. If the table does not have any suitable key, then it can be set + to replica identity <quote>full</quote>, which means the entire row becomes + the key. This, however, is very inefficient and should only be used as a + fallback if no other solution is possible. If a replica identity other + than <quote>full</quote> is set on the publisher side, a replica identity + comprising the same or fewer columns must also be set on the subscriber + side. See <xref linkend="SQL-CREATETABLE-REPLICA-IDENTITY"> for details on + how to set the replica identity. If a table without a replica identity is + added to a publication that replicates <command>UPDATE</command> + or <command>DELETE</command> operations then + subsequent <command>UPDATE</command> or <command>DELETE</command> + operations will cause an error on the publisher. <command>INSERT</command> + operations can proceed regardless of any replica identity. </para> <para> |