On Thu, June 9, 2011 11:59, Jerry Schwartz wrote: > <snip> > >> >>A single table is always consistent. Data inconsistency occurs in sets of >>interrelated tables, in other words, on the database level. >> > [JS] Not even a single table is always consistent (unless there is > transactions). Consider a single transaction that consists of two steps: > > 1. Delete record A > 2. Add record B > > Now consider > > 1. Delete record A > -Backup starts- > 2. Add record B > > You have no idea whether or not record B will be in your backup. > > Worse things can happen, of course: > > 1. Delete record A > !!KABOOM!! > > The data in the table is not going to be consistent. You'd have to analyze > the > data to find out what did and didn't happen before the crash, back out > step 1, > and re-run that transaction in the application. > > > Regards, > > Jerry Schwartz Ah, LOCK TABLE which is the myisam� equivalent of "tranactions".� That will deal with the problem of backup in the middle yes?�� If that won't work then you do need transactions.� IMHO.
------ William R. Mussatto Systems Engineer http://www.csz.com 909-920-9154
