From Jim.Conboy@trw.com Thu, 28 Jun 2001 08:00:51 -0700 From: "Jim Conboy" Date: Thu, 28 Jun 2001 08:00:51 -0700 Subject: RE: Speed up massive delete Message-ID: MIME-Version: 1.0 Content-Type: text/plain Well, that IS true (actually I think its NOLOGGING for index creation).  But if you have massive amounts of INSERTS or DELETES, dropping the index first and then re-creating can help.   If the number of deletes is truly large, and you've got spare disk space, and the table can be off-line for a while, you might try CTAS (create table as select) using UNRECOVERABLE, to make a second copy of the table with just the rows you want to keep.  Then drop or rename the old table, rename the new table, and re-create the indexes with NOLOGGING.  In removing 3 million rows from a 9 million row table this method was very fast compared to DELETE.   Jim >>> TS2017@emirates.com 06/28/01 10:58AM >>> Yes that is right. rgds amar -----Original Message----- From: MHately@etech-uk.com [mailto:MHately@etech-uk.com] Sent: Thursday, June 28, 2001 6:25 PM To: Multiple recipients of list ORACLE-L Subject: Re: Speed up massive delete Ron, How does creating indexes as UNRECOVERABLE save time when you insert data? As far as I'm aware the only operation it will save time on is the initial creation. Regards, Mike |--------+-----------------------> |        |          "Ron Rogers" | |        |             | |        |                       | |        |          06/28/01     | |        |          02:51 PM     | |        |          Please       | |        |          respond to   | |        |          ORACLE-L     | |        |                       | |--------+----------------------->   >-------------------------------------------------------------------|   |                                                                   |   |       To:     Multiple recipients of list ORACLE-L                |   |                                             |   |       cc:     (bcc: Mike Hately/ETECH)                            |   |       Subject:     Re: Speed up massive delete                    |   >-------------------------------------------------------------------| Jack Drop the indexes first before you do the deletes will save you time by not creating logs for the indexes being deleted. On my large activity files I have created the indexes as "Unrecoverable" saving time when I add data or delete data. ROR mªÖªm >>> nlzanen1@EY.NL 06/28/01 05:45AM >>> Hi All, I have to do some pretty big deletes on a test environment and they are estimated to take for ever. Are there any options to speed it up? Jack ===================================================================== De informatie verzonden in dit e-mailbericht is vertrouwelijk en is uitsluitend bestemd voor de geadresseerde. Openbaarmaking, vermenigvuldiging, verspreiding en/of verstrekking van deze informatie aan derden is, behoudens voorafgaande schriftelijke toestemming van Ernst & Young, niet toegestaan. Ernst & Young staat niet in voor de juiste en volledige overbrenging van de inhoud van een verzonden e-mailbericht, noch voor tijdige ontvangst daarvan. 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A copy of these terms and conditions is available on request free of charge. ===================================================================== -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author:   INET: nlzanen1@EY.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@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: Ron Rogers   INET: RROGERS@galottery.org 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@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:   INET: MHately@etech-uk.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@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).