Re: analyze table with "list chainged rows" or "compute statistics"

In article <3AE2AF56.E61BD2A2_at_yahoo.com>, David <david_petit_at_yahoo.com> writes:
>Hi all,
>
>
> I want to find the number of migrated rows in table testing. I found
>that I can use "analyze table testing list chainged rows" and "select
>count(*) from chained_rows" AND "analyze table testing compute
>statistics" and "select * from dba_tables where table_name = 'TESTING'".
>Which one is better and faster?
>
>Thanks,
>David

David, if you just want to find the tables with chaining then just run the analyzes and look at dba_tables. (And estimates on a decent size sample are good enough to find chaining for large tables). Then divide the number of chained rows by the total row count to find those tables with chaining greater than whatever percentage you set as your limit. I like one-half of one percent or no more than one IO in 200 being on a chained row.

The analyze with chained rows options is only useful if you intend to fix the chaining by saving, deleting, and re-inserting the chained row. If you are going to fix the problem using exp/imp, create table as select, or alter table move then there is probably no need to list the rows.

• Mark D. Powell --
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