I had to read my book to find the answer to this one ;)
If you specify (at least under 8.1.5): alter table tabX drop column colX; then there is no checkpoint and you generate the worst volume of rollback. If you specify: alter table tabX drop column colX checkpoint NNN; then you checkpoint every NNN rows. If you specify: alter table tabX drop column colX checkpoint; without a rowcount, then you checkpoint every 512 rows. You post doesn't include the checkpoint keyword, so I guess you hit the top option. Jonathan Lewis http://www.jlcomp.demon.co.uk Next Seminar - UK, April 3rd - 5th http://www.jlcomp.demon.co.uk/seminar.html Host to The Co-Operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/faq/ind_faq.html Author of: Practical Oracle 8i: Building Efficient Databases -----Original Message----- To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> Date: 26 March 2002 04:08 |OK, I asked this on Friday when people were thinking about going home and I |didn't get any answers... any takers? | |-----Original Message----- |Sent: Friday, March 22, 2002 1:01 PM |To: Multiple recipients of list ORACLE-L | | |I've got a "process" which is consuming RBS to the point of failure (running |out of tablespace). I have very little control of the code so using set |transaction is not a possibility. | |The SQL that is failing is "alter table tabname drop column colname" with no |checkpoint being specified. According to the documentation, when no |checkpoint integer is specified then it defaults to committing every 512 |rows but I suspect this is not happening hence the rollback problem. Does |anyone have experience with dropping columns on large amounts of data and |specifying the checkpoint integer? If you don't specify the checkpoint does |it really default to 512 like the documentation says? How would I test the |checkpoint default? (We're running Oracle 8172 on Linux.) | |As an alternative I'm thinking about doing an "alter table tabname set |unused column colname" then manually doing an "alter table tabname drop |unused columns" later with a set transaction. | |Any ideas? | |Steve Orr |Bozeman, MT -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jonathan Lewis INET: [EMAIL PROTECTED] 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: [EMAIL PROTECTED] (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).