Portal | Manuals | References | Downloads | Info | Programs | JCLs | Mainframe wiki | Quick Ref
IBM Mainframe Computers Forums Index
IBM Mainframe Computers Forums Index Mainframe: Search IBM Mainframe Forum: FAQ Memberlist Profile Log in to check your private messages Log in
CPU time for a query

Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> DB2
View previous topic :: :: View next topic  
Author Message

New User

Joined: 16 Apr 2007
Posts: 1
Location: Chennai

PostPosted: Mon Apr 23, 2007 4:37 pm    Post subject: CPU time for a query
Reply with quote

I am trying to come up with some usage vs cost metric for our DB2 Subsystems. In that regard, I am trying to find some industry benchmarks on running queries. Can anyone provide a ball-park figure for the CPU time taken to run a) Simple b) Medium c) Complex query?

Simple query: A select statement without where clause
Medium query: Contains where clause
Complex query: Contains joins
Back to top
View user's profile Send private message

dick scherrer

Site Director

Joined: 23 Nov 2006
Posts: 19270
Location: Inside the Matrix

PostPosted: Tue Apr 24, 2007 8:34 am    Post subject:
Reply with quote


I'd suggest that you reconsider your "grouping"s.

Rarely should there be a production query with no where clause - especially not online. Batch queries are often considered separately from online queries when performing performance analysis.

CPU time is only one measurement of cost.

A query that joins 3 tables efficiently to retriece 5 rows will take fewer DB2 cpu cycles than a single select that traverses 10 million rows - with or without a where.

Depending on the speed of your cpu(s), the type of dasd used, the number of rows, the length of the rows etc, what would be good "ball-park figures" will vary. You might talk with your IBM rep about a starting point for your environment.

As you begin, you will want to become familiar with the DB2 Statistics and Accounting records.

With some work, you will be able to report usage by various groupings. Assigning a $ cost to them will take much more work unless somone just invents amounts to use.
Back to top
View user's profile Send private message
View previous topic :: :: View next topic  
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> DB2 All times are GMT + 6 Hours
Page 1 of 1


Search our Forum:

Similar Topics
Topic Author Forum Replies Posted
No new posts Comparing 2 Files using Current time arunsoods DFSORT/ICETOOL 7 Fri Sep 22, 2017 6:00 pm
No new posts Create procedure issues -628 when add... chandraBE DB2 1 Mon Sep 18, 2017 12:16 pm
No new posts Regarding time parameter shanthi gude JCL & VSAM 7 Mon Sep 04, 2017 2:31 pm
No new posts Can we limit length in concatenation ... balaji81_k DB2 7 Tue Aug 22, 2017 2:50 am
No new posts Need DB2 query to fetch previous row ! Chandan1993 DB2 10 Sat Jun 03, 2017 10:43 am

Back to Top
Job Vacancies | Forum Rules | Bookmarks | Subscriptions | FAQ | Polls | Contact Us