RE: which tables have lowest cache hits?
echo "set isolation dirty read; select d.name[1,4],t.tabname,p.pf_bfcread
bufreads,p
.pf_bfcwrite bufwrites,p.pf_dskreads pagreads,p.pf_dskwrites pagwrites from
sysdbspaces d,
systabnames t ,sysptntab p where t.partnum = p.partnum and
trunc((hex(p.partnum)/1048576)) =
d.dbsnum and d.dbsnum != 1 and d.is_temp <> 1 order by 1,2" | dbaccess
sysmaster
The read cache % will be:
(pf_bfcread - pf_dskreads) / pf_bfcread * 100
If your table is fragmented this query will return multiple rows so you
might want to do a group by t.tabname.
Regards,
Bill Dare
> -----Original Message-----
> From: hajek@nspuh.cz [SMTP:hajek@nspuh.cz]
> Sent: Friday, November 07, 2003 4:43 AM
> To: informix-list@iiug.org
> Subject: which tables have lowest cache hits?
>
> Hi,
>
> our buffer rate increased (to about 6) and it seems it is because low
> write cache hit (about 93%). We have now 130 MB of buffers and I do
> not want to increase it ... yet. What I'd like to know now is, which
> tables have lowest cache hit? Is it possible to find it? How?
>
> Thanks,
> Michal
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