Message-Id: <10645.118884@fatcity.com> From: Chuck Hamilton Date: Tue, 10 Oct 2000 10:20:15 -0700 (PDT) Subject: Re: Performance - Chained Rows --0-2053999932-971198415=:20848 Content-Type: text/plain; charset=us-ascii Absolutely. You first need to determine whether these are true chained rows or migrated rows. Both show up in the chain_cnt column of dba_tables. If they are migrated rows (most likely), increase the PCTFREE for the table, and reorg it. If they are true chained rows and the table contains LOBs, store the LOBs in a separate lob segment. If they're chained rows and you're not using LOBs your choices are to increase the block size to something large enough to accomodate the largest row, or live with it. Be advised that changing the block size requires recreating the database. "Weerd Kirsten, E.C. de" wrote: Hi, I'm still looking for a cause of performance problems ... I have found a table, very frequently used in forms and procedures, with about 10% chained rows. Other most frequently used tables have about 0,3 % chained rows. Could this be an issue ??? Greets, Kirsten -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Weerd Kirsten, E.C. de INET: Kirsten.deWeerd@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@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). --------------------------------- Do You Yahoo!? Get Yahoo! Mail - Free email you can access from anywhere! --0-2053999932-971198415=:20848 Content-Type: text/html; charset=us-ascii

Absolutely. You first need to determine whether these are true chained rows or migrated rows. Both show up in the chain_cnt column of dba_tables. If they are migrated rows (most likely), increase the PCTFREE for the table, and reorg it. If they are true chained rows and the table contains LOBs, store the LOBs in a separate lob segment. If they're chained rows and you're not using LOBs your choices are to increase the block size to something large enough to accomodate the largest row, or live with it. Be advised that changing the block size requires recreating the database.

  "Weerd Kirsten, E.C. de" <Kirsten.deWeerd@Oranjewoud.nl> wrote:

Hi,

I'm still looking for a cause of performance problems ...

I have found a table, very frequently used in forms and procedures,
with about 10% chained rows. Other most frequently used tables have about
0,3 % chained rows. Could this be an issue ???

Greets,

Kirsten
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Weerd Kirsten, E.C. de
INET: Kirsten.deWeerd@Oranjewoud.nl

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