| From: | Andres Freund <andres(at)2ndquadrant(dot)com> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: MVCC catalog access |
| Date: | 2013-05-23 03:02:18 |
| Message-ID: | 20130523030218.GA7149@alap2.anarazel.de |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 2013-05-22 22:51:13 -0400, Robert Haas wrote:
> In discussions today, Tom Lane suggested testing the time to start up
> a backend and run a simple query such as "SELECT 2+2" in the absence
> of a relcache file.
> I did this and can't measure any overhead as a result of MVCC catalog
> access. I tried it with no active connections. I tried it with 600
> idle active connections (to make taking MVCC snapshots more
> expensive).
Did you try it with the 600 transactions actually being in a transaction
and having acquired a snapshot?
> All in all, I'm still feeling optimistic.
+1. I still feel like this has to be much harder since we made it out to
be hard for a long time ;)
Greetings,
Andres Freund
--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
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