From 0f5ca02f53ac2b211d8518f0882c49284c0c9610 Mon Sep 17 00:00:00 2001 From: Alexander Korotkov Date: Tue, 7 Apr 2020 23:51:10 +0300 Subject: Implement waiting for given lsn at transaction start This commit adds following optional clause to BEGIN and START TRANSACTION commands. WAIT FOR LSN lsn [ TIMEOUT timeout ] New clause pospones transaction start till given lsn is applied on standby. This clause allows user be sure, that changes previously made on primary would be visible on standby. New shared memory struct is used to track awaited lsn per backend. Recovery process wakes up backend once required lsn is applied. Author: Ivan Kartyshov, Anna Akenteva Reviewed-by: Craig Ringer, Thomas Munro, Robert Haas, Kyotaro Horiguchi Reviewed-by: Masahiko Sawada, Ants Aasma, Dmitry Ivanov, Simon Riggs Reviewed-by: Amit Kapila, Alexander Korotkov Discussion: https://postgr.es/m/0240c26c-9f84-30ea-fca9-93ab2df5f305%40postgrespro.ru --- src/backend/nodes/outfuncs.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'src/backend/nodes/outfuncs.c') diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index 5b826509ebe..47753b42c69 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -2784,6 +2784,28 @@ _outDefElem(StringInfo str, const DefElem *node) WRITE_LOCATION_FIELD(location); } +static void +_outTransactionStmt(StringInfo str, const TransactionStmt *node) +{ + WRITE_NODE_TYPE("TRANSACTIONSTMT"); + + WRITE_STRING_FIELD(savepoint_name); + WRITE_STRING_FIELD(gid); + WRITE_NODE_FIELD(options); + WRITE_BOOL_FIELD(chain); + WRITE_ENUM_FIELD(kind, TransactionStmtKind); + WRITE_NODE_FIELD(wait); +} + +static void +_outWaitClause(StringInfo str, const WaitClause *node) +{ + WRITE_NODE_TYPE("WAITCLAUSE"); + + WRITE_STRING_FIELD(lsn); + WRITE_UINT_FIELD(timeout); +} + static void _outTableLikeClause(StringInfo str, const TableLikeClause *node) { @@ -4334,6 +4356,12 @@ outNode(StringInfo str, const void *obj) case T_PartitionRangeDatum: _outPartitionRangeDatum(str, obj); break; + case T_TransactionStmt: + _outTransactionStmt(str, obj); + break; + case T_WaitClause: + _outWaitClause(str, obj); + break; default: -- cgit v1.2.3