AW: alter table: 'lost' extents

I've just made some deeper investigation. One of extents (I took the largest for simplicity) reported by chunk's extent list (oncheck -pe) as belonging to the dropped table is also not reflected in the "Chunk free list" (the third page of any non-root chunk, can be displayed with 'oncheck -pP CHUNK_NUM 2', and recursively with 'oncheck -pP CHUNK_NUM NEXT' where NEXT is displaeyed in the 'next' field of the page header in the previous output; NEXT=0 means last page in a linked list) That means, the this extent will never be re-used by the engine. It's lost forever. The conclusion is: Informix is not releasing 'old' (previous version) extents after table subjected to 'in-place-alter-table' is dropped !!!!!!!!!!!!!! I'll try to wait for response from the 'list' for a few days and file a bug to PA. P.S. I converted my 9.21 DEV database to 9.40 and repeated the experiment. No change. Lost space again. THIS IS A REALLY BAD PROBLEM ------------------------------------------ Alexey Sonkin -----Original Message----- From: Alexey Sonkin [mailto:alexeis@grandvirtual.com] Hi, everybody, I've just found a very unpleasant problem with 9.21uc4 I have a huge table that was altered (column added) when it was big enough. 'Alter table' was 'in-place' - just because the operation went very fast. After that, a lot of inserts were made, and old records were not updated. Later, the table was dropped. When I made an analysis of disk extents with 'oncheck -pe', I was surprised: a lot of extents (actually, containing all the 'before alter table' records) were not released by the 'drop table'!!! Is it a known bug? Is it fixed in 9.40? Is there way to return extents to the free page pool? ------------------------------------------ Alexey Sonkin sending to informix-list sending to informix-list