Thread: pgsql: Avoid SnapshotResetXmin() during AtEOXact_Snapshot()

Avoid SnapshotResetXmin() during AtEOXact_Snapshot()

For normal commits and aborts we already reset PgXact->xmin
Avoiding touching highly contented shmem improves concurrent
performance.

Simon Riggs

Discussion: CANP8+jJdXE9b+b9F8CQT-LuxxO0PBCB-SZFfMVAdp+akqo4zfg@mail.gmail.com

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/42b4b0b2413b9b472aaf2112a3bbfd80a6ab4dc5

Modified Files
--------------
src/backend/access/transam/xact.c |  6 +++---
src/backend/utils/time/snapmgr.c  | 21 ++++++++++++++++++---
src/include/utils/snapmgr.h       |  2 +-
3 files changed, 22 insertions(+), 7 deletions(-)