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Diffstat (limited to 'doc/src/sgml/ref/begin.sgml')
| -rw-r--r-- | doc/src/sgml/ref/begin.sgml | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/doc/src/sgml/ref/begin.sgml b/doc/src/sgml/ref/begin.sgml index c23bbfb4e71..66d9ad7cb23 100644 --- a/doc/src/sgml/ref/begin.sgml +++ b/doc/src/sgml/ref/begin.sgml @@ -21,7 +21,7 @@ PostgreSQL documentation <refsynopsisdiv> <synopsis> -BEGIN [ WORK | TRANSACTION ] [ <replaceable class="parameter">transaction_mode</replaceable> [, ...] ] +BEGIN [ WORK | TRANSACTION ] [ <replaceable class="parameter">transaction_mode</replaceable> [, ...] ] [ WAIT FOR LSN <replaceable class="parameter">lsn_value</replaceable> [TIMEOUT <replaceable class="parameter">number_of_milliseconds</replaceable> ] ] <phrase>where <replaceable class="parameter">transaction_mode</replaceable> is one of:</phrase> @@ -63,6 +63,17 @@ BEGIN [ WORK | TRANSACTION ] [ <replaceable class="parameter">transaction_mode</ <xref linkend="sql-set-transaction"/> was executed. </para> + + <para> + The <literal>WAIT FOR</literal> clause allows to wait for the target log + sequence number (<acronym>LSN</acronym>) to be replayed on standby before + starting the transaction in <productname>PostgreSQL</productname> databases + with master-standby asynchronous replication. Wait time can be limited by + specifying a timeout, which is measured in milliseconds and must be a positive + integer. If <acronym>LSN</acronym> was not reached before timeout, transaction + doesn't begin. Waiting can be interrupted by cancelling + <literal>BEGIN</literal> command. + </para> </refsect1> <refsect1> @@ -146,6 +157,10 @@ BEGIN; different purpose in embedded SQL. You are advised to be careful about the transaction semantics when porting database applications. </para> + + <para> + There is no <literal>WAIT FOR</literal> clause in the SQL standard. + </para> </refsect1> <refsect1> |