From 2516c592db97f285925667aafb34fc2de4286282 Mon Sep 17 00:00:00 2001 From: Ashwin Agrawal Date: Fri, 2 Aug 2019 15:02:28 -0700 Subject: [PATCH v1 1/3] Optimize TransactionIdIsCurrentTransactionId() If xid is current top transaction, can fast check for the same and exit early. This should optmize for current heap but also works very well for future AMs, which don't have separate xid for subtransactions. This optimization was proposed by Andres. --- src/backend/access/transam/xact.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 1bbaeeebf4d..41952bc4d26 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -871,6 +871,9 @@ TransactionIdIsCurrentTransactionId(TransactionId xid) if (!TransactionIdIsNormal(xid)) return false; + if (TransactionIdEquals(xid, GetTopTransactionIdIfAny())) + return true; + /* * In parallel workers, the XIDs we must consider as current are stored in * ParallelCurrentXids rather than the transaction-state stack. Note that -- 2.19.1