Delete performance - long RID list chain

Lisa Ouellette

Delete performance - long RID list chain
I've been out of the DB2 loop for a while. Hi everyone! And Happy New Year.

I remember indexes with many duplicate values would create long RID chains that could negatively impact delete performance. Delete would have to scan the entire chain to find the row to be deleted.

Is this still an issue? Or has there been an improvement?

Thanks in advance!

_____________________________________________________________________
* IDUG North America * Anaheim, California * May 2-6 2011 * http://IDUG.ORG/NA *
* If you are going to attend only one conference this year, this is it! *
_____________________________________________________________________
http://www.IDUG.org/mentor
How can you expand your staff or do succession planning in this economy?
Mentoring is a proven, economical, way to train the next generation of DB2 Users!
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Joe Geller

Re: Delete performance - long RID list chain
(in response to Lisa Ouellette)
Lisa,
There has been an improvement (a long time ago).
With Type 2 indexes (which now are the only kind), the
duplicate key entries are stored in RID order. DB2 can
do a binary search to find an entry when you are
deleting a row.

Joe



I've been out of the DB2 loop for a while. Hi everyone! And Happy New Year.

I remember indexes with many duplicate values would create long RID chains that could negatively impact delete performance. Delete would have to scan the entire chain to find the row to be deleted.

Is this still an issue? Or has there been an improvement?

Thanks in advance!

_____________________________________________________________________
* IDUG North America * Anaheim, California * May 2-6 2011 * http://IDUG.ORG/NA *
* If you are going to attend only one conference this year, this is it! *
_____________________________________________________________________
http://www.IDUG.org/mentor
How can you expand your staff or do succession planning in this economy?
Mentoring is a proven, economical, way to train the next generation of DB2 Users!
_____________________________________________________________________

If you need to change settings, http://www.idug.org/cgi-bin/wa?A0=DB2-L is the home of IDUG's Listserv

Lisa Ouellette

Re: Delete performance - long RID list chain
(in response to Joe Geller)
Makes sense. Well, I should have known that though. I haven't been out of the loop that long - guess I lost some brain cells. Thanks!

_____________________________________________________________________
* IDUG North America * Anaheim, California * May 2-6 2011 * http://IDUG.ORG/NA *
* If you are going to attend only one conference this year, this is it! *
_____________________________________________________________________
http://www.IDUG.org/mentor
How can you expand your staff or do succession planning in this economy?
Mentoring is a proven, economical, way to train the next generation of DB2 Users!
_____________________________________________________________________

If you need to change settings, http://www.idug.org/cgi-bin/wa?A0=DB2-L is the home of IDUG's Listserv