| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
| Cc: | pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: eviscerating the parser |
| Date: | 2011-05-22 00:31:12 |
| Message-ID: | BANLkTikXWa1kGOS1+8mgtOdc2xyE-HmKvQ@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Sat, May 21, 2011 at 7:51 PM, Robert Haas <robertmhaas(at)gmail(dot)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
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