Re: INDEX REBUILD

Paul Bennett wrote:
>
> I have issued the command alter index <index name> rebuild on a few
> indexes who had a lot of extents (in order to put the entire index in
> one extent and make it faster), however, when i run this command the
> number of extents does fall to one, but the size of the extent is just
> whatever the initial extent size was in the first place. i would except
> this number to get bigger. if the index used to have 200 extents in
> addition to the initial extent how can the entire index fit into the
> initial extent now that I rebuilt it. Every index that I have rebuilt
> has done this. is it just a coincidence? is it because rows were added
> to make the other extents necessary and then some rows where deleted and
> therefore there are holes in the index?

Are your first extent very big and the others small, e g first extent is 20M and the others are 4k? If the extents are of equal size, then 200 extents fitting into 1 sounds weird.

> am I doing the right thing to the indexes? did i misinterpret what the
> rebuild command does?

Remember to always add the tablespace-clause to your rebuild-statement, otherwise they end up in your default tablespace, no matter what tablespace they are in before you rebuild. Quite a 'gotcha'. The storage parameters of the new index will equal the storage parameters of the old index, though, that's why the size of the first extent always is equal.

Njål Received on Fri Nov 13 1998 - 00:00:00 CST