Re: How do "locks" work when doing deletes?

> <D4kLaho@PacBell.COM> writes > >Hi all, > > > >Looking for a few simple answer here (at least I believe they are). > > > >If I have a table having say a million rows called "ttable", and 2 > >users simultaneousIy execute a "delete from ttable;" command, will > >there be any table locks involved. . . > > > >a) . . .if the database has logging? > > > >b) . . .if the database does not have logging? > > > >c) . . .or how about if I have only 1 user performing the command? > > Would that make a difference with respect to a) & b)? > > > >TIA >>>> Depending on your configuration, this could cause you two potential problems (as you are probably already aware): 1) lock table overflow 2) long transaction Even with just 1 user. With logging off, and LOCK TABLE IN EXCLUSIVE MODE, you avoid both 1) and 2) AND you prevent the 2 users from getting in each other's way. If you truly want to delete all rows from that large a table, I would just drop and recreate it.... it's MUCH MUCH faster that way. No lock problems, no transaction problems, no 2-user problems. You just need to make sure you put in the dbspace and extent sizes. (I wish Informix would do this for us in dbschema!)