rebuild in production

[farrokhp]

I would like to initiate a rebuilding index task in our Production Database. Just want to verify:

Does issue this is OK for each table:

alter index I_INDIVIDUAL_SURNAME rebuild unrecoverable tablespace NS_BIG_INDEXES
/


what will happen to first and next extent sizes? Do I need to add Storage parameter to better organize the indexes?

Is it possible the performance degrade instead of boost?

can I run the script during working hours?

Any other consideration? It is a mission critical production DB 8.0 on Win NT and its about 20 GB.

[Mr.Hanky]

If this is mission critical I would take a backup of the index DDL first.
If you are going to do this online than you will need roughly twice the space for the new index. Oracle will create the new index, than drop the old one after it is in place. So if you have a 100M index you will need a 200M tablespace to re-build it online.

MH

[marist89]

Your index will keep their INITIAL and NEXT values and NOT inherit those of the tablespace. When in doubt, specify these values.

If you have adequate resources, you can build in PARALLEL. (I think you can do this in 8.0)