Re: EXP Parameters to take backup of 110 GB database

On Aug 3, 6:40 pm, joel garry <joel-ga..._at_home.com> wrote:
> I mentioned Connor McDonald's list of ways to speed up exp/imp in
> another thread, for my particular requirements I:
> Use schema level exports with DIRECT=Y compress=N recordlength=65535
> Use exp with buffer=20000000 full=y rows=n compress=n
> Sometimes use the QUERY parameter if appropriate.
> Sometimes use transportable tablespaces if appropriate.

For long-running exports, also use CONSISTENT=Y so that, in the event that some (hopefully not too many) inserts occur after sequences are exported, sequences will not be out of sync with table columns which use the sequences to populate values. If there is a lot of write activity during a CONSISTENT=Y export though, one may get the snapshot-too-old error. However CONSISTENT=Y is the only thing that will guarantee that sequences stay in sync w/ the tables' data.

Also, not sure how many rows the biggest table has, but "exp" will NOT properly export a table w/ > 4 billion rows; it will export 4 billion then fail for the remainder of the table, leaving it incomplete, and then the whole export will "terminate successfully with warnings" -- a pretty remarkable message if you ask me. Failure to dump out all the rows is a "warning." (This is for any error that causes "exp" to bail on a table including snapshot-too-old.

I agree that 110 GB was a lot a couple years ago, but not any more. My 84-year-old mom has 1/2 a terabyte, as much as a Citibank data center had back in the 80's.

John Hinsdale Received on Sat Aug 04 2007 - 10:35:08 CDT