Subject Re: [firebird-support] Trace cause of performance drop
Author Thomas Steinmaurer
Hello Michael,

> I have a performance problem at a customer site.
> At this point I suspect one specific external user connection to cause
> the problems, but I can't pinpoint it so exactly just yet.
> But there is one table, where there is inserted records almost all the
> time.
> When the user connects, does whatever he has to (this will cause reads
> and some inserts into various tables).
> Then when the user completes the current routine, there will be updates
> of some 10-15 tables, which takes no time.
> Then an insert is done into one table. And the prepare of this insert
> can take up to 2 seconds. Normally it would be instantly.
> The entire database is around 96Gb
> Firebird is 2.5.
> Running Classic on Windows
> What will cause a prepare to become so slow?

What exact Firebird 2.5 version are you running? A vaguely remember an
issue where prepare time can be quite long when the statement is
referencing very large tables.

Btw, as you are on 2.5, you can simply use the Trace API to try to spot
the slowest activities.

With regards,
Thomas Steinmaurer

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