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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Compute statisics
Jared:
In the Oracle 8.1.6 Docs:
Oracle8i Designing and Tuning for Performance
8 Gathering Statistics
Table 8-2 Default Table and Index Values When
Statistics are Missing
Kevin
-----Original Message-----
Sent: Thursday, June 07, 2001 6:21 AM
To: Multiple recipients of list ORACLE-L
Are these defaults recorded somewhere that mere mortals have access to?
Jared
On Thursday 07 June 2001 00:25, Mogens Nørgaard wrote:
> Any stat missing in a CBO situation will be set to the hard-coded default
> values found in the source code. One example (out of about 40 or so
> values) is default selectivity for equality predicates. Before 7.3 it was
> 0.125 (meaning that a where= condition would assume you needed to scan
> 1/8th of the table). In 7.3 and later it was fortunately set to 0.01 (1%).
> Another of my favorite default values is number of leaf blocks in an
> index. It's 25.
>
> Connor McDonald wrote:
> > Hi Jared,
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jared Still INET: jkstill_at_cybcon.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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Toepke, Kevin M INET: ktoepke_at_cms.cendant.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 Thu Jun 07 2001 - 06:40:30 CDT
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