Re: HELP!! - ORA-01555: snapshot too old: Rollback Segment number 2 ....."_SYSSMSU5$ too small"

"Ursula Lee" <ursula.lee_at_thales-is.com> wrote in message news:cb6be0$31i9_at_imsp212.netvigator.com...
> Thank you so much Howard, that document is very useful.
>
> I guess my action will be:
> 1. Try to increase the size in UNDO Retention, I changed to few second
> only last time as I encounter similar problem during deletion. Seems
> like the size was not big enough, I changed the retention to clean up
> space faster. Perhaps this is wrong.

What? I didn't understand a word of that, but how anyone who is told in black and white "increase the size of your undo tablespace" translates that into 'increase my setting for undo retention', I honestly can't work out. If you increase undo *retention* you are only going to make the space requirements for the undo tablespace worse than they already are.

> Any suggestion on how long for retention?

How long is your longest query? How much use of flashback do you intend to make? Did you read sections 10.1.3 and 10.1.4??

> 2. If #1 doesn't work, I will recreate the UNDO tablespace...
> According to your document, I must create a new UNDO tablespace (I will
> use client tool), then change the configuration to point to the new
> tablespace.

Sorry. You've lost me now. I have no idea what you're talking about, but whatever it is, it's not what I've written in the ebook, and it's not what I've posted here. I'll try it again, then:

Increase the size of your existing undo tablespace. Do so by increasing the size of an existing database file, or by adding a new database file to the existing tablespace. Alter database datafile '/x/y.dbf' resize 100M is how you do the former. Alter tablespace undo add datafile '/x/y.dbf' size 100m is how you do the latter.

HJR Received on Mon Jun 21 2004 - 08:18:32 CDT