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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Fast Refresh of Materialized views
How do I find out if that is the case .The no of new inserts/updates is much
lesser than the total no of rows in the tables.So why would the fast refresh
take longer .
Can we index the MV logs to speed up the process.
vikas
-----Original Message-----
Sent: Tuesday, August 28, 2001 4:11 PM
To: Multiple recipients of list ORACLE-L
It may be that your fast refresh is actually doing a lot of work. This would happen if many rows in the source table were changed. If 99% of the rows changed, then a complete refresh will be faster, because you don't have the added overhead of reading the logs to determine which rows to refresh - you just refresh them all.
If only 1% of the rows changed then the fast refresh will indeed be fast - faster than a complete refresh.
Somewhere in between there's a break even point. It may be that many rows have changed - enough to take you past the break even point.
> We've noticed that our fast refresh takes longer than complete refresh -
and
> that's puzzling .We have MV logs based on the PK of the FACT table - and
the
> MV's are JOIN ONLY .
> Any suggestions would be welcome !
>
> vikas
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Vikas Kawatra
> INET: VKawatra_at_innoventry.com
>
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Greg Moore INET: sqlgreg_at_pacbell.net Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Vikas Kawatra INET: VKawatra_at_innoventry.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Tue Aug 28 2001 - 17:58:39 CDT
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