How can the Reorg times be estimated in DB2?
Is there a formula or script or select that might help
to give me an idea?
Thanks,

JMaria

Unfortunately, there is no formula. It is much like trying to estimate the time you will run a marathon: you won't know your result until you actually run it for the first time.

You may not be able to estimate, but there are some things you can do to try and improve reorg time:
DB2 Database for Linux, UNIX, and Windows


Some additional info to what's documented above:

- DB2 will use private sorts for index key sorting regardless of the value of intra_parallel. If intra_parallel is ON, DB2 can take advantage of multiple CPUs on the server (it will use multiple subagents). See the following link regarding intra_parallel if you're using v9.5:
IBM DB2 9.5 Information Center for Linux, UNIX, and Windows

- Increasing sortheap and making sure sheapthres is "at least sortheap x the number of processors used" can be helpful. DB2 may still need to spill the sort so increasing tempspace's bufferpool can help to minimize disk I/O. It's also recommended to have multiple containers for your tempspace, each container on a different disk.

If this is a 64-bit instance on AIX, verify that ulimit(data) is set to unlimited or some high value (ulimit -d).

Have you ever done it?

No, but how difficult could that be?

No idea but I think it would require a lot of training.

There is a way to get it from the history prior past reorgs that gets save on some db2 tables!! i just got an average estimation base on that!! and it did work fine!! thanks for your responses!