I do not need to do insert updates from many threads. I want to do it from one thread.
My current MySQL architecture is that I have a table with same layout as the main one, to hold new and updated objects. When there is enough objects, I begin a big INSERT SELECT ... ON DUPLICATE KEY UPDATE and stuff that into the master table. i On Tue, Sep 13, 2011 at 1:11 PM, Marti Raudsepp <ma...@juffo.org> wrote: > On Tue, Sep 13, 2011 at 19:34, Robert Klemme <shortcut...@googlemail.com> > wrote: > > I don't think so. You only need to catch the error (see attachment). > > Or does this create a sub transaction? > > Yes, every BEGIN/EXCEPTION block creates a subtransaction -- like a > SAVEPOINT it can roll back to in case of an error. > > > Yes, I mentioned the speed issue. But regardless of the solution for > > MySQL's "INSERT..ON DUPLICATE KEY UPDATE" which Igor mentioned you > > will have the locking problem anyhow if you plan to insert > > concurrently into the same table and be robust. > > In a mass-loading application you can often divide the work between > threads in a manner that doesn't cause conflicts. > > For example, if the unique key is foobar_id and you have 4 threads, > thread 0 will handle rows where (foobar_id%4)=0, thread 1 takes > (foobar_id%4)=1 etc. Or potentially hash foobar_id before dividing the > work. > > I already suggested this in my original post. > > Regards, > Marti > > -- > Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance >
