Re: [Exim] exim's databases and sql

On Mon, Oct 06, 2003 at 08:21:11AM -0400, Richard Welty wrote:
> no question here. different databases will behave differently on this. i
> don't know how MySQL does locking for writes; PostgreSQL uses MVCC and
> writes cannot block reads. M$ SQL Server uses a nasty little promotable
> row locking scheme that can cause major problems if the number of rows
> affected by a write exceed a certain threshold.

If you use MySQL's default table type, it's as bad as using the current
setup (it locks entire tables for single writes).
You have to use something like the InnoDB tables, and use the
--skip-external-locking to prevent the OS locking the database files per
write also. This is only safe of only one DB is accessing the DB files.