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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Validate index
But an online validation will not populate index_stats which would be useful for finding indexes with poor space usage chrematistics. Being that this is the whole point of running validate index in this case I think the best alternate is to manually calculate the space requirement of the index and then compare this to the actual usage. If the index is twice the calculated requirement then it is probably worth rebuilding from a space management point of view. Rebuilding will not help select performance and could harm insert performance if the indexed column values repeat. Repeating keys would have to go into existing, probably full, blocks causing block splits. Assigning an adequate pct_free on the rebuild would help avoid this problem. But when disk space is limited reclaiming space can become a required activity.
IMHO -- Mark D Powell --
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of Feighery Raymond
Sent: Friday, August 06, 2004 9:55 AM
To: 'oracle-l_at_freelists.org'
Subject: RE: Validate index
ANALYZE ... VALIDATE INDEX will put a shared lock on the table preventing
DML.
Unless you are using 9i or later, when you can use the ONLINE option.
Impact: it depends.
Ray
-----Original Message-----
From: jaysingh1_at_optonline.net [mailto:jaysingh1_at_optonline.net]
Sent: Friday, August 06, 2004 2:38 PM
To: oracle-l_at_freelists.org
Subject: Validate index
Hi All,
Does validate index (pk index) enforce any exclusive lock on the table?
The reason I am asking is that we are trying to validate few indexes(to find out fregmentation) on production (while the site is live). What could be the impact on parent table?
Thanks
Sami
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