| From: | Mark Kirkwood <markir(at)paradise(dot)net(dot)nz> |
|---|---|
| To: | Luke Lonergan <llonergan(at)greenplum(dot)com> |
| Cc: | stange(at)rentec(dot)com, Greg Stark <gsstark(at)mit(dot)edu>, Dave Cramer <pg(at)fastcrypt(dot)com>, Joshua Marsh <icub3d(at)gmail(dot)com>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Hardware/OS recommendations for large databases ( |
| Date: | 2005-11-24 09:24:35 |
| Message-ID: | 438586D3.9010701@paradise.net.nz |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-performance |
Luke Lonergan wrote:
> That says it's something else in the path. As you probably know there is a
> page lock taken, a copy of the tuple from the page, lock removed, count
> incremented for every iteration of the agg node on a count(*). Is the same
> true of a count(1)?
>
Sorry Luke - message 3 - I seem to be suffering from a very small
working memory buffer myself right now, I think it's after a day of
working with DB2 ... :-)
Anyway, as I read src/backend/parser/gram.y:6542 - count(*) is
transformed into count(1), so these two are identical.
Cheers (last time tonight, promise!)
Mark
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Mark Kirkwood | 2005-11-24 09:26:44 | Re: Hardware/OS recommendations for large databases ( |
| Previous Message | Luke Lonergan | 2005-11-24 09:22:03 | Re: Hardware/OS recommendations for large databases ( |