From ab9c43381ef7a7333086107847413e0b593854d0 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Thu, 27 Apr 2017 15:49:22 -0700 Subject: [PATCH] Don't build full initial logical decoding snapshot if NOEXPORT_SNAPSHOT. Earlier commits (56e19d938dd14 and 2bef06d5164) make it cheaper to create a logical slot if not exporting the initial snapshot. If NOEXPORT_SNAPSHOT is specified, we can skip the overhead, not just when creating a slot via sql (which can't export snapshots). As NOEXPORT_SNAPSHOT has only recently been introduced, this shouldn't be backpatched. --- src/backend/replication/walsender.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index 43c8a73f3e..2a6c8bb62d 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -873,6 +873,7 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd) if (cmd->kind == REPLICATION_KIND_LOGICAL) { LogicalDecodingContext *ctx; + bool need_full_snapshot = false; /* * Do options check early so that we can bail before calling the @@ -884,6 +885,8 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd) ereport(ERROR, (errmsg("CREATE_REPLICATION_SLOT ... EXPORT_SNAPSHOT " "must not be called inside a transaction"))); + + need_full_snapshot = true; } else if (snapshot_action == CRS_USE_SNAPSHOT) { @@ -906,10 +909,11 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd) ereport(ERROR, (errmsg("CREATE_REPLICATION_SLOT ... USE_SNAPSHOT " "must not be called in a subtransaction"))); + + need_full_snapshot = true; } - ctx = CreateInitDecodingContext(cmd->plugin, NIL, - true, /* build snapshot */ + ctx = CreateInitDecodingContext(cmd->plugin, NIL, need_full_snapshot, logical_read_xlog_page, WalSndPrepareWrite, WalSndWriteData); -- 2.40.0