query slow in 9i, but not slow in 8i 2004-03-01 - By Mark Richard
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I am unfortunately speaking from heresay, however I heard once that having
histograms all over the place can slow down parsing as they have to be
inspected. I was left with the impression that unless the data is skewed
enough to warrant a histogram then there actually is a negative cost
associated with having too many histograms.
Surely someone on this list can either support me or shoot me down on this
one?
Wolfgang Breitling
<breitliw@(protected) To: oracle-l@(protected)
c.com > cc:
Sent by: Subject: Re: RE: query slow in 9i, but not slow in 8i
oracle-l-bounce@(protected)
eelists.org
02/03/2004 12:04
Please respond to
oracle-l
As long as it works for you - nothing.
However - to quote myself:
"Histograms are like drugs ¨C An overdose [of histograms] can kill
[performance]. "
And like drugs, the practice may seem harmless and you get used to it,
until one day ...
"It seems easier just to ... " is never a good enough reason for me to do -
or not do - something.
At 04:14 PM 3/1/2004, you wrote:
>If you have the window and use monitoring what is wrong with getting
>histograms on every table? I 'm doing all new development with new queries
>getting developed everyday. It seems easier just to put histograms on
>everything. I have the window to do this overnight and will have it when
we
>go live?
Wolfgang Breitling
Oracle7, 8, 8i, 9i OCP DBA
Centrex Consulting Corporation
http://www.centrexcc.com
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