Re: eviscerating the parser

On Sat, May 21, 2011 at 7:51 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> Another point is that parsing overhead is quite obviously not the
> reason for the massive performance gap between one core running simple
> selects on PostgreSQL and one core running simple selects on MySQL.
> Even if I had (further) eviscerated the parser to cover only the
> syntax those queries actually use, it wasn't going to buy more than a
> couple points.

Incidentally, prepared transactions help a lot.  On unpatched master,
with pgbench -T 300 -S -n:

tps = 10106.900801 (including connections establishing)
tps = 10107.015951 (excluding connections establishing)

vs.

tps = 18212.053457 (including connections establishing)
tps = 18212.246077 (excluding connections establishing)

The reasons for the magnitude of that difference are not entirely
apparent to me.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company