Performance and 72.devel

Started by John Summerfieldover 24 years ago5 messagesbugs
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#1John Summerfield
pgtest@os2.ami.com.au

I checked out the latest updates about 14 hours ago.

I've also put together a new box, featuring an Athlon running at 1.3 Mhz. I cloned the OS (Red Hat Linux 7.1) - I'd copied it from one disk to another fairly recently, and so the software setup is pretty well precisely what I've been using all along.

A job which took well over three hours on my Pentium II@133 (mostly CPU time) runs in a little over two (mostly I/O), a result that doesn't surprise me a lot.

It crossed my mind that PG is probably using new log files all the time:

2001-09-15 20:26:56 [30787] DEBUG: recycled transaction log file 0000000000000032
2001-09-15 20:29:36 [30788] DEBUG: recycled transaction log file 0000000000000033
2001-09-15 20:29:36 [30788] DEBUG: recycled transaction log file 0000000000000034
2001-09-15 20:35:11 [30791] DEBUG: recycled transaction log file 0000000000000035
2001-09-15 20:35:11 [30791] DEBUG: recycled transaction log file 0000000000000036

and so on.

I think that if it actually reused them instead of deleting old files and creating new ones then on my system (256 Mbytes of RAM) a few log files would fit entirely in cache and it would really fly.

#2Thomas Lockhart
lockhart@fourpalms.org
In reply to: John Summerfield (#1)
Re: Performance and 72.devel

...

I think that if it actually reused them instead of deleting old files...

That is in fact what it does for at least the upcoming 7.2 release.

- Thomas

#3John Summerfield
pgtest@os2.ami.com.au
In reply to: Thomas Lockhart (#2)
Re: Performance and 72.devel

On Mon, 17 Sep 2001, Thomas Lockhart wrote:

...

I think that if it actually reused them instead of deleting old files...

That is in fact what it does for at least the upcoming 7.2 release.

It's not what I see now in 7.2devel. Unless the changes are uncommitted (or commited in the past few days) it's not working.

Or if it is reusing them, it's renaming them too.

#4Tom Lane
tgl@sss.pgh.pa.us
In reply to: John Summerfield (#3)
Re: Performance and 72.devel

John Summerfield <pgtest@os2.ami.com.au> writes:

Or if it is reusing them, it's renaming them too.

That is what the "recycling..." message is all about...

regards, tom lane

#5John Summerfield
pgtest@os2.ami.com.au
In reply to: Tom Lane (#4)
Re: Performance and 72.devel

On Wed, 19 Sep 2001, Tom Lane wrote:

John Summerfield <pgtest@os2.ami.com.au> writes:

Or if it is reusing them, it's renaming them too.

That is what the "recycling..." message is all about...

1) Why rename them?
2) Does anyone have a better idea how it floods my cache?

I'll try again when someone sorts out why CVS isn't working as described.