Re: POC: Cache data in GetSnapshotData()

On Tue, Mar 1, 2016 at 12:59 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:

>Don't we need to add this only when the xid of current transaction is valid?  Also, I think it will be better if we can explain why we need to add the our >own transaction id while caching the snapshot.

I have fixed the same thing and patch is attached.

Some more tests done after that

pgbench write tests: on 8 socket, 64 core machine.

/postgres -c shared_buffers=16GB -N 200 -c min_wal_size=15GB -c max_wal_size=20GB -c checkpoint_timeout=900 -c maintenance_work_mem=1GB -c checkpoint_completion_target=0.9

./pgbench -c $clients -j $clients -T 1800 -M prepared postgres

A small improvement in performance at 64 thread.