Re: indexes and extents

On Fri, 10 Oct 1997, Mark Collins wrote: } > Even multiple detached (and that is the keyword here) indexes from the same } > table in the same dbspace can suffer this fate. ODS records detached } > indexes in the tablespace tablespace and in sysmaster as if they were } > separate tables so extents of separate detached indexes, regardless of what } > table they belong to, cannot share extents or compress their extents } > together. } Agreed. I thought the original poster said after he created the indexes } he had the multiple extents. Since you can only create one index at a } time, each index should be contiguous until some insert activity causes a } new extent to be needed. The next index (with its own tablespace number) } would then grab space after the end of the previous index. Assuming, of } course, that there is enough contiguous space in the dbspace to start } with. Correct? Mark Collins mcollins@us.dhl.com The problem lies in how } easily and dangerously we forget that manipulating things is not the same } as understanding them. All correct except that if the index had just been created it would have only one extent per chunk that it is contained in (is that awkward or what?). As you say either that was some whopper of an index to fill so many chunks or the chunks it did go into were already badly fragmented, otherwise extent compression would pack the index into a single extent. If the dbspace is that fragmented that all of the indexes and tables in it should be compressed wither by dropping and rebuilding or clustering the tables if any. Otherwise my comments are still valid. Art S. Kagel, kagel@bloomberg.com