"Ann W. Harrison" <aharrison@...> wrote:

>
> >Why i want it ? In case of lot of inserts in one table from dozen of
> >clients, partitioned table increase performance due to paralel write to
> >this table. If table is not partitioned the write processes are lock
> >each other because of write to the same part of disk (db space).
>
> Actually, inserts don't lock against each other in Firebird.

Neither they do in Oracle, AFAIK.

I may be wrong, but IMO, he's talking about page I/O concurrency, not about
insert locks. It's supposed that flushing two pages to different disks is
faster than to a single one. I doubt that it makes sense to partition a
table into two files located on the same disk. As for the table data stored
on different disks, I'd prefer to trust RAID-5 in this case. But this is
just me.

But, obviously, it's makes enough sense to have a guaranteed separated
device I/O if it affects not only parallel updates but the overall
performance. I'm talking about undo/redo logs which are written
independently from data pages. But this is a bit different story.


Dmitry