At 6/23/2003 08:01 AM (Monday), Tim Ledgerwood wrote:

> > You shouldn't set ALL transactions' isolation level to concurrency.
> >Only report transactions that need serializable read. Update/insert
> >transactions may be (and should be) "read commited".
>
>Why?

Because when updating records you want the most up to date version of that
record available. That's the one you want to update. The way to get it is
to have the update transaction use "read committed" so it always sees the
most recently committed data in the database.

Same with inserts. If you are inserting a record which has references to
other records, or which has looked up values from other tables, you want to
pick those values from the most recent, permanent data in the database. You
will be sure to have that data available when you use "read committed".