lock allocation

i am running a dummy update to remove an in place alter. update t_contact set first_name=first_name where 1=1; i am curious for this table which is less than one million rows why the engine would dynamically allocate 2 million locks. the first million make sense to me but why more locks than rows in the tables? is it due to indexes? thanks tom

Hello Tom, yes it could be indexes, also rows may be moved from their current page to a different one. This will change the indexes too. i would lock the table in exclusive mode or update it in smaller pieces using a cursor or unlogged or.. Superboer. On 4 mei, 16:26, Tom Lehr <tomc...@gmail.com> wrote: > i am running a dummy update to remove an in place alter. > > update t_contact set first_name=first_name where 1=1;> > i am curious for this table which is less than one million rows why > the engine would dynamically allocate 2 million locks. the first > million make sense to me but why more locks than rows in the tables? > is it due to indexes? > > thanks > tom

Yes. Indexes and I believe VARCHAR columns will consume more locks. Regards. On Wed, May 4, 2011 at 3:26 PM, Tom Lehr <tomcaml@gmail.com> wrote: > i am running a dummy update to remove an in place alter. > > update t_contact set first_name=first_name where 1=1;> > i am curious for this table which is less than one million rows why > the engine would dynamically allocate 2 million locks. the first > million make sense to me but why more locks than rows in the tables? > is it due to indexes? > > thanks > tom > _______________________________________________ > Informix-list mailing list > Informix-list@iiug.org > http://www.iiug.org/mailman/listinfo/informix-list > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently...