We run a sweep every night in a cron job, a sweep triggered by an
interval would affect a real user.

-----Original Message-----
From: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com] On Behalf Of berniebialt
Sent: Thursday, June 09, 2005 9:19 AM
To: firebird-support@yahoogroups.com
Subject: [firebird-support] Re: Poor Performance

Ann:

I ran gstat -h this morning after "sweeping" the database from yesterday
and there is almost a 1,000 transaction difference between "Oldest
Active" and "Next Transaction". This is certaintly more than several
hundred which is the number I believe that you indicated could cause
performance problems. All though the performance is still fine today, I
am wondering if I should be "Sweeping" this database on a nightly basis,
or set the sweep interval at a low level. I am trying to get my arms
around what these numbers represent, what is affecting them, and if they
are the root of the problem. Any input would be greatly appreciated.

Thanks!

Bernie


Database header page information:
Flags 0
Checksum 12345
Generation 525487
Page size 4096
ODS version 10.1
Oldest transaction 524565
Oldest active 524566
Oldest snapshot 524565
Next transaction 525474
Bumped transaction 1
Sequence number 0
Next attachment ID 0
Implementation ID 16
Shadow count 0
Page buffers 0
Next header page 0
Database dialect 3
Creation date Jul 14, 2004 20:58:53
Attributes force write

Variable header data:
*END*


Thanks!

Bernie


--- In firebird-support@yahoogroups.com, "Ann W. Harrison"
<aharrison@i...> wrote:

> berniebialt wrote:
> > Ann:
> >
> > Thanks for respond to me. I ran gstat and here are some of the
> > details that I see:
> >
> > Oldest Transaction 434143
> > Oldest Active 446334
> > Oldest Snapshot 446334
> > Next Transaction 446335
> >
> > Is the issue the difference between Oldest Transaction and Next
> > Transaction?
>
> No, the problem would be between the oldest active and the next.

In

> this case, there's only a single transaction running. To analyze

the

> problem, you're going to have to run gstat -h when the performance

is bad.

>
> > I noticed it is a differnce of over 12000. If this is the problem,
> > what would cause this to occur? and how could I keep this from
> > happening going forward.
> >
>
> The oldest transaction - also called the oldest interesting

transaction

> - is the oldest transaction in any state other than committed.

Sweep

> moves that number along. 12000 is not very bad.
>
> Regards,
>
>
> Ann

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