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Home -> Community -> Mailing Lists -> Oracle-L -> RE: about analyse table..
Can't you also analyze an entire schema to make it easier, there's a dbms
package in the admin directory?
kev
-----Original Message-----
Carmichael
Sent: Friday, March 23, 2001 8:35 AM
To: Multiple recipients of list ORACLE-L
if you have your database in the "CHOOSE" mode for the optimizer (using the cost-based optimizer) and you don't analyze your tables, Oracle doesn't have good information to determine the query path.
If you do "analyze table <tablename> compute statistics" the entire table is read to gather the statistics
if you do "analyze table <tablename> estimate statistics" (and you can give it the percentage to estimate on) then Oracle takes a sampling of the data to generate the statistics
analyze table will also cause all indexes to be analyzed, although you can analyze the indexes separately.
If you do analyze the tables in your database, make sure to analyze all of them as a query with even one table not analyzed will have performance degradation.
For more details, you can start with the SQL Reference manual and look up the ANALYZE command
>From: "Saurabh Sharma" <saurabhs_at_fcsltd.com>
>Reply-To: ORACLE-L_at_fatcity.com
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>Subject: about analyse table..
>Date: Thu, 22 Mar 2001 22:00:23 -0800
>
>hello,
>
>i'm not very familiar with the analyse table command. and not fully aware
>of it's advantage or limits to analyse the tables.
>could anyone pls help me with this cmd, how to see the analysed statistics,
>etc.
>any help is highly appreciated.
>
>thanks in advance.
>
>saurabh sharma
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rachel Carmichael INET: carmichr_at_hotmail.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: Kevin Kostyszyn INET: kevin_at_dulcian.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 Fri Mar 23 2001 - 11:38:20 CST
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