Re: Block count usage by a table

From: MotoX <rat_at_tat.a-tat.com>
Date: Mon, 6 Jul 1998 08:15:07 +0100
Message-ID: <899709234.27280.0.nnrp-11.c2de712e@news.demon.co.uk>

Er, why? The blocks would still be assigned to the table/index in question.

But sure, the data is not necessarily 'packed' tight into the 'least number of blocks'. But then that's a different matter. Storage clauses will have an effect on the packing or rows in a table, as will the 'staleness' of indexes and their storage parameters. Likewise, lots of chained migrated rows will have an effect.

I'd use ANALYSE over the technique listed below for a better picture - unless you are on an old Oracle release.

MotoX.

johnvue_at_gte.net wrote in message <6npf4n$8aa$1_at_news-1.news.gte.net>...
>I see the following query mentioned to find out how many blocks a
>table is using up:
>
>select COUNT(DISTINCT(SUBSTR(ROWID,1,8)||SUBSTR(ROWID,15,4)))
> Blocks_Used
> from sometable;
>
>
>If most/all of the rows are chained/migrated, won't this query be
>inaccurate?
Received on Mon Jul 06 1998 - 02:15:07 CDT