Re: Speed up massive delete

From: <MHately_at_etech-uk.com>
Date: Thu, 28 Jun 2001 03:51:21 -0700
Message-ID: <F001.0033B7B3.20010628032548@fatcity.com>

Jack,

First of all you could explore these options : Could you truncate the table ?
Could you copy out the rows you want to keep (using CTAS NOLOGGING) /drop the table/rename 'kept-rows' table to original name? Are the rows in a partition that you could drop?

If none of these are possible these measures will improve performance : Disable log archiving.
Make sure your redo logs are on the fastest disk available. Consider allocating larger logs temporarily if you checkpoint frequently. Remove any unnecessary indexes. Oracle won't have to keep them updated PLUS the optimiser will be likely to scan the table (which is probably what you want) if there's no suitable index.
Remove any unnecessary foreign keys and triggers.

You may be advised to use NOLOGGING. Ignore this advice. NOLOGGING does not affect deletes and will make no difference.

Regards,
Mike Hately,
Oracle DBA

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  |       cc:     (bcc: Mike Hately/ETECH)                            |
  |       Subject:     Speed up massive delete                        |
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Hi All,

I have to do some pretty big deletes on a test environment and they are estimated to take for ever.
Are there any options to speed it up?

Jack

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Received on Thu Jun 28 2001 - 05:51:21 CDT