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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Analyzed Schema
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Hi Kirsten,
We are a perfect example. Our app runs RBO, and it runs fine. The task of going to true CBO and putting stats on the database has been brought up, but my reaction has been 'why fix something that isn't broken?' It would be a painful task with a whole load of code-tuning to do, and explaining (and defending) the optimizer to developers. De-support of RBO has been brought up - but how long has Oracle been saying that? Forever.
My last position was a different story. With a data warehouse/data mart, it's imperative to have as good statistics as you can afford (time-wise) in order to take advantage of the optimizer's DW functionality. Bad statistics will send your performance down the tubes.
The only thing I REALLY miss is being able to get good info out of the data dictionary - I know we have chained rows in one of our largest tables (the test databases do). However, I'll never really know for sure because I can't analyze the table. Even a light estimate takes an unacceptable amount time.
Others may have more convincing reasons.
HTH
Lisa
-----Original Message-----
From: Weerd Kirsten, E.C. de [mailto:Kirsten.deWeerd_at_Oranjewoud.nl]
Sent: Thursday, October 19, 2000 10:01 AM
To: Multiple recipients of list ORACLE-L
Subject: Analyzed Schema
Hi all,
Are there situations where it is best to work without an analyzed schema, or should all schema's be analyzed an a regular basis ?
Or : What are the pro's and con's of analyzing a schema ???
Greets,
Kirsten
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Weerd Kirsten, E.C. de INET: Kirsten.deWeerd_at_Oranjewoud.nl 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). ------_=_NextPart_001_01C039CE.AAFC7C76 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printableReceived on Thu Oct 19 2000 - 08:15:35 CDT
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<TITLE>RE: Analyzed Schema</TITLE>
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<P><FONT SIZE=3D2>Hi Kirsten, </FONT>
</P>
<P><FONT SIZE=3D2>We are a perfect example. Our app runs RBO, and =
it runs fine. The task of going to true CBO and putting stats on = the database has been brought up, but my reaction has been 'why fix = something that isn't broken?' It would be a painful task with a = whole load of code-tuning to do, and explaining (and defending) the = optimizer to developers. De-support of RBO has been brought up - = but how long has Oracle been saying that? Forever.</FONT></P>
<P><FONT SIZE=3D2>My last position was a different story. With a =
data warehouse/data mart, it's imperative to have as good statistics as = you can afford (time-wise) in order to take advantage of the = optimizer's DW functionality. Bad statistics will send your = performance down the tubes.</FONT></P>
<P><FONT SIZE=3D2>The only thing I REALLY miss is being able to get =
good info out of the data dictionary - I know we have chained rows in = one of our largest tables (the test databases do). However, I'll = never really know for sure because I can't analyze the table. = Even a light estimate takes an unacceptable amount time.</FONT></P>
<P><FONT SIZE=3D2>Others may have more convincing reasons.</FONT>
</P>
<P><FONT SIZE=3D2>HTH</FONT>
<BR><FONT SIZE=3D2>Lisa</FONT>
</P>
<BR>
<P><FONT SIZE=3D2>-----Original Message-----</FONT>
<BR><FONT SIZE=3D2>From: Weerd Kirsten, E.C. de [<A =
HREF=3D"mailto:Kirsten.deWeerd_at_Oranjewoud.nl">mailto:Kirsten.deWeerd_at_Ora= njewoud.nl</A>]</FONT>
<BR><FONT SIZE=3D2>Sent: Thursday, October 19, 2000 10:01 AM</FONT>
<BR><FONT SIZE=3D2>To: Multiple recipients of list ORACLE-L</FONT>
<BR><FONT SIZE=3D2>Subject: Analyzed Schema</FONT>
</P>
<BR>
<P><FONT SIZE=3D2>Hi all,</FONT>
</P>
<P> <FONT SIZE=3D2>Are there =
situations where it is best to work without an analyzed</FONT>
<BR><FONT SIZE=3D2>schema, or should all schema's be analyzed an a =
regular basis ?</FONT>
</P>
<P> <FONT SIZE=3D2>Or : What =
are the pro's and con's of analyzing a schema ???</FONT>
</P>
<P> <FONT =
SIZE=3D2>Greets,</FONT>
</P>
<P><FONT SIZE=3D2> Kirsten</FONT>
</P>
<P><FONT SIZE=3D2>-- </FONT>
<BR><FONT SIZE=3D2>Please see the official ORACLE-L FAQ: <A =
HREF=3D"http://www.orafaq.com" = TARGET=3D"_blank">http://www.orafaq.com</A></FONT>
<BR><FONT SIZE=3D2>-- </FONT>
<BR><FONT SIZE=3D2>Author: Weerd Kirsten, E.C. de</FONT>
<BR><FONT SIZE=3D2> INET: Kirsten.deWeerd_at_Oranjewoud.nl</FONT>
</P>
<P><FONT SIZE=3D2>Fat City Network Services -- (858) =
538-5051 FAX: (858) 538-5051</FONT>
<BR><FONT SIZE=3D2>San Diego, =
California -- Public Internet = access / Mailing Lists</FONT>
<BR><FONT =
SIZE=3D2>---------------------------------------------------------------= -----</FONT>
<BR><FONT SIZE=3D2>To REMOVE yourself from this mailing list, send an =
E-Mail message</FONT>
<BR><FONT SIZE=3D2>to: ListGuru_at_fatcity.com (note EXACT spelling of =
'ListGuru') and in</FONT>
<BR><FONT SIZE=3D2>the message BODY, include a line containing: UNSUB =
ORACLE-L</FONT>
<BR><FONT SIZE=3D2>(or the name of mailing list you want to be removed =
from). You may</FONT>
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