Optimize TransactionIdIsCurrentTransactionId().

Thomas Munro <tmunro@postgresql.org>

Commit: 695c5977c8bc115029a85dcc1821d7b0136b4e4c
Author: Thomas Munro <tmunro@postgresql.org>
Date: 2019-11-11T03:33:04Z
Releases: 13.0
Optimize TransactionIdIsCurrentTransactionId().

If the passed in xid is the current top transaction, we can do a fast
check and exit early.  This should work well for the current heap but
also works very well for proposed AMs that don't use a separate xid
for subtransactions.

Author: Ashwin Agrawal, based on a suggestion from Andres Freund
Reviewed-by: Thomas Munro
Discussion: https://postgr.es/m/CALfoeiv0k3hkEb3Oqk%3DziWqtyk2Jys1UOK5hwRBNeANT_yX%2Bng%40mail.gmail.com

Files

PathChange+/−
src/backend/access/transam/xact.c modified +3 −0

Discussion