Subject Re: Unexpected for me or really unexpected?
Author Alexander V.Nevsky
--- In ib-support@y..., "Ivan Prenosil" <prenosil@m...> wrote:

Hi, Ivan.
> About sweep - do you really need it ?
> Do you need to do it daily ?
> Why do you want to drive away users to do sweep ?

About 30 000 transactions are performed on this database dayli. And
our applications are designed so that main selects are made in 1
read_only read_commited transaction and data changing with small
selects (if needed) are made in short snapshot ones. I think sweep
will have little effect if it will be done when there are active
transactions opened 15 hours ago.

> About statistical calculations - is not snapshot transaction mode
enough for your purposes ?

Two reasons:
1. Users can make "partilal calculations" on the same tables and
general "full" process can fail with lock conflict. They are'nt such a
fanatics to work at night, but our headquarters is in St. Petersburg
and we have office even in Vladivostok.
2. Earlier we made it with users present making especial kind of
pessimistic locking but it slows process that requires about 3 hours
now. And it were very seldom and so unrealized occurances of "hanging"
process, we used IB4 on SCO at this time.

Thank for your reply.