Forest Wilkinson wrote:
> If I add ON UPDATE CASCADE to my foreign key definitions, how much will it
> affect performance for queries that don't trigger the cascade?
The trigger fired on the PK table does a check if the key fields changed first. Therefore, at the first time
offireing for this action during backend lifetime it'll do some syscache lookups and remember the
comparision functions to call for this check. From then on it'll call the comparision functions directly and
returnimmediately without doing any real work if the key effectively didn't change.
I expect it to not affect the performance significant. Would be nice though if you'd run some tests and share the
results with us.
Jan
--
#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me. #
#================================================== JanWieck@Yahoo.com #
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com