IBM Mainframe Forum Index
 
Log In
 
IBM Mainframe Forum Index Mainframe: Search IBM Mainframe Forum: FAQ Register
 

DB2 Utility performance


IBM Mainframe Forums -> DB2
Post new topic   Reply to topic
View previous topic :: View next topic  
Author Message
Pandora-Box

Global Moderator


Joined: 07 Sep 2006
Posts: 1592
Location: Andromeda Galaxy

PostPosted: Sat Aug 08, 2009 2:49 pm
Reply with quote

Hi,

We had changed RUNSTATS & REORG which were executing in different steps to one single step in order to reduce the CPU time but inspite of doing that there is not much change?

Experts need your suggesion and advice on the same.

Thanks in advance.
Back to top
View user's profile Send private message
enrico-sorichetti

Superior Member


Joined: 14 Mar 2007
Posts: 10872
Location: italy

PostPosted: Sat Aug 08, 2009 2:59 pm
Reply with quote

Why would You think that running as a single step would reduce resource usage ?

the only things that get executed once instead of two are

JCL related processing
converter/interpreter/jes stuff
allocation
program initialization
DB2 connect
program fetch

relly nothing worth the trouble of restructuring the process
Back to top
View user's profile Send private message
Pandora-Box

Global Moderator


Joined: 07 Sep 2006
Posts: 1592
Location: Andromeda Galaxy

PostPosted: Sat Aug 08, 2009 4:15 pm
Reply with quote

My assumption is We wont be having too many hits to DB2 by having something like one below where we execute them in one single step

Code:


REORG TABLESPACE DBNAME.TSNAME             
PART 01 LOG NO KEEPDICTIONARY                     
STATISTICS TABLE (ALL) UPDATE (ALL)               
INDEX(INDEX1)



My assumption is given the code in one above format happens parallely then in two different steps.

Correct me if i am wrong Enrico icon_redface.gif


Thanks in advance
Back to top
View user's profile Send private message
dick scherrer

Moderator Emeritus


Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix

PostPosted: Sun Aug 09, 2009 12:33 am
Reply with quote

Hello,

Quote:
My assumption is given the code in one above format happens parallely then in two different steps.
Quote:
Correct me if i am wrong
No, they happen serially, rather than in parallel. Note the start and stop times of the 2 processes.
Back to top
View user's profile Send private message
Pandora-Box

Global Moderator


Joined: 07 Sep 2006
Posts: 1592
Location: Andromeda Galaxy

PostPosted: Wed Aug 12, 2009 4:13 pm
Reply with quote

Thanks dick.

Is there any way to reduce the CPU & ELAPSED time consumed?
Back to top
View user's profile Send private message
expat

Global Moderator


Joined: 14 Mar 2007
Posts: 8797
Location: Welsh Wales

PostPosted: Wed Aug 12, 2009 4:25 pm
Reply with quote

Whether in one step or two steps, the amount of work being processed is the same. Therefor the amount of processor resource consumed will be the same.

With the details given bt Enrico, you could expect to say maybe a millisecond or two of CPU.

Reducing elapsed time depends on a whole lot of different factors, often where many are not under your own control.
Back to top
View user's profile Send private message
Pandora-Box

Global Moderator


Joined: 07 Sep 2006
Posts: 1592
Location: Andromeda Galaxy

PostPosted: Wed Aug 12, 2009 4:35 pm
Reply with quote

Got that Expat thanks for your advice icon_smile.gif
Back to top
View user's profile Send private message
dick scherrer

Moderator Emeritus


Joined: 23 Nov 2006
Posts: 19244
Location: Inside the Matrix

PostPosted: Wed Aug 12, 2009 7:45 pm
Reply with quote

Hello,

Quote:
Is there any way to reduce the CPU & ELAPSED time consumed
Probably not the cpu time. Possibly the elapsed time by changing when these are run (an empty machine) or installing faster equipment.
Back to top
View user's profile Send private message
View previous topic :: :: View next topic  
Post new topic   Reply to topic View Bookmarks
All times are GMT + 6 Hours
Forum Index -> DB2

 


Similar Topics
Topic Forum Replies
No new posts REASON 00D70014 in load utility DB2 6
No new posts exploiting Z16 performance PL/I & Assembler 2
No new posts ISRSUPC search utility - using high l... TSO/ISPF 2
No new posts JOIN STATEMENT PERFORMANCE. DFSORT/ICETOOL 12
No new posts Any JCL or VSAM Utility to get number... JCL & VSAM 1
Search our Forums:

Back to Top