Subject | Re: problem ... (switching back to postgresql) |
---|---|
Author | Alexander V.Nevsky |
Post date | 2001-11-27T20:11:17Z |
--- In ib-support@y..., cuncua1@y... wrote:
I never saw FreeBSD too, but have experience of migration from IB4.
Usually speed problem is optimizer - for many queries optimizer of IB5
and higher build another plans than IB4. Sometimes better, sometimes
worse. Check plan FB use for slow queries and if it is bad, try to
optimize it changing query or using explicit plan. Do you access gdb
file made by IB4 with FB? It can be source of problem too, I recommend
to create new instance via backup/restore.
semaphores can limit amount of connections for classic IB/FB but not
speed and are not used in superserver version at all. Among FB config
and database parameters speed is mainly dependent on database page
size and database cashe buffers. I think wrong tuning of TCP/IP and
DNS can decrease speed, especially time of connect establishing, but
I'm not especialist on this stuff.
Best regards.
> Do you know why is the FreeBSD port so slow (compared for examplewith the old Interbase 4.0 on the same platform) ?.
I never saw FreeBSD too, but have experience of migration from IB4.
Usually speed problem is optimizer - for many queries optimizer of IB5
and higher build another plans than IB4. Sometimes better, sometimes
worse. Check plan FB use for slow queries and if it is bad, try to
optimize it changing query or using explicit plan. Do you access gdb
file made by IB4 with FB? It can be source of problem too, I recommend
to create new instance via backup/restore.
> It is a platform problem (semaphores,etc.)?As far as I can remember from SCO experience some years ago,
semaphores can limit amount of connections for classic IB/FB but not
speed and are not used in superserver version at all. Among FB config
and database parameters speed is mainly dependent on database page
size and database cashe buffers. I think wrong tuning of TCP/IP and
DNS can decrease speed, especially time of connect establishing, but
I'm not especialist on this stuff.
Best regards.