From cspence@FuelSpot.com Fri, 14 Sep 2001 07:38:27 -0700 From: Christopher Spence Date: Fri, 14 Sep 2001 07:38:27 -0700 Subject: RE: Tablespace (datafile reducing) Message-ID: MIME-Version: 1.0 Content-Type: text/plain !! Please do not post Off Topic to this List !! I know a few people (actually on the LazyDBA list) have done tests and each time they have said the checkpoint time has been insignificantly altered. I cannot say I have done these tests, and go by the theory of using smaller data files rather than larger ones for portability and locking reasons. I never see any problems with checking pointing due to size. I hope some of the people who have played with this are around and have the results. I do not have anything official to offer on this as I am merely going off what other people have said that have tried it, and the experiences I have had (although not with that many data files). If no one steps up, I may put together some test environment to put concrete fact either way. "Do not criticize someone until you walked a mile in their shoes, that way when you criticize them, you are a mile a way and have their shoes." Christopher R. Spence Oracle DBA Phone: (978) 322-5744 Fax: (707) 885-2275 Fuelspot 73 Princeton Street North, Chelmsford 01863 -----Original Message----- Sent: Friday, September 14, 2001 10:50 AM To: Multiple recipients of list ORACLE-L !! Please do not post Off Topic to this List !! Chris, Are these tests results published someplace? "Tests have been done on many databases with 3500+ data files and shown the difference to be insignificant." Tom Mercadante Oracle Certified Professional -----Original Message----- Sent: Friday, September 14, 2001 9:50 AM To: Multiple recipients of list ORACLE-L !! Please do not post Off Topic to this List !! >Having too many datafiles is not good for performance, >updating datafile headers during checkpointing. I disagree, unless you have an unreasonable amount, there is minor almost not noticeable difference. Tests have been done on many databases with 3500+ data files and shown the difference to be insignificant. "Do not criticize someone until you walked a mile in their shoes, that way when you criticize them, you are a mile a way and have their shoes." Christopher R. Spence Oracle DBA Phone: (978) 322-5744 Fax: (707) 885-2275 Fuelspot 73 Princeton Street North, Chelmsford 01863 -----Original Message----- Sent: Thursday, September 13, 2001 8:55 PM To: Multiple recipients of list ORACLE-L !! Please do not post Off Topic to this List !! Kishore, Having too many datafiles is not good for performance, updating datafile headers during checkpointing. If you are on 8i you can create a 2GB tablespace, and use the alter table move command to move all the tables in that tablespace to the new 2GB tablespace. All associated indexes will become unusable, so make sure you alter index rebuild ... If the tablespace has indexes rather than tables then you could do a alter index rebuild ... to move them to the new tablespace. If you are not on 8i then you can use export/ import. Export all tables in the tablespace, Drop the tables, Drop the tablespace, Recreate new tablespace (same name) with single datafile, Import all tables Regards Suhen !! Please do not post Off Topic to this List !! Hello DBAs I have a tablespace , who has 10 datafiles of 200MB each, it was here before I even joined. I was thinking for the contention and want to combine them all to one single large datafile of 2gig. How do I get rid off all those datafiles and ghet them in one large datafiles?? Any help in this regard Thank you very much Kishore __________________________________________________ Terrorist Attacks on U.S. - How can you help? Donate cash, emergency relief information http://dailynews.yahoo.com/fc/US/Emergency_Information/ -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Kishore INET: mcgoracle@yahoo.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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Suhen Pather INET: Suhen.Pather@strandbags.com.au 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: Christopher Spence INET: cspence@FuelSpot.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). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Mercadante, Thomas F INET: NDATFM@labor.state.ny.us 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: Christopher Spence INET: cspence@FuelSpot.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).