Subject Re: Group Commits
Author Roman Rokytskyy
Jim, Dmitry,

> Can we suppose scenarios when even 20-50 ms delay on commit is
> unacceptable?
> If so, may I suggest that a zero config option means no group commit?
> Or perhaps we may introduce isc_tpb_no_group_commit causing
> transaction to flush its buffers immediately?

Can I suggest an optional isc_group_commit_period parameter?

Jim, consider please the auto-commit mode in JDBC. Even if we don't
like it, it is perfectly standard mode. When each UPDATE statement
will take 200 ms (or even 50 ms), people will notice general slowdown
of the applications. The experienced users might solve this issue
relatively easy, but I suspect that newcomers will be frustrated and
will jump to other DB (MySQL for example).

Also I think that specifying a period on per-server basis (as config
param, if I understood correctly) is too coarse-grained. One might
want to have different delays on per-database basis, or even for
different applications (one is read-mostly, for example, and another
is batch import).

Please add this as an optional TPB param with possibility to specify
different delays. People need a possibility to use this feature only
when it's needed.

I also volunteer to test different values with the AS3AP benchmark, so
we can see what improvement it brings.