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  1. #1
    Join Date
    Jan 2009
    Location
    Zoetermeer, Holland
    Posts
    746

    Unanswered: Never been aware

    Hi, I am running some test scripts on my Express-C 10.5 (linux) and I encounter some behaviour of DB2 that surprices me. The first client who logges on to a database which is not activated pays the price of starting & initializing the logs & buffers. That is common knowledge.

    But when you are the last to disconnect (or deactivate) this can take a much longer time! Thinking about it it makes sence: all the dirty pages must be cleaned and after that the logs have to be archived.
    But the thing is:
    - 1 run my test scripts updating like a mad man: 2:30 minutes
    - 2 I leave the database idle for 30 minutes
    - 3 I deactivate the database: this takes more than 5 minutes !!

    I wonder: is there something I can do in that idle time start cleaning the buffer pools and archive log files? Some kind of: 'be prepared to close a.s.a.p.' command?

    P.S. I wish all you lucky b*st*rds travelling to Barcelona next week a good conference.
    Somewhere between " too small" and " too large" lies the size that is just right.
    - Scott Hayes

  2. #2
    Join Date
    Mar 2003
    Posts
    280
    Quote Originally Posted by dr_te_z View Post
    Hi, I am running some test scripts on my Express-C 10.5 (linux) and I encounter some behaviour of DB2 that surprices me. The first client who logges on to a database which is not activated pays the price of starting & initializing the logs & buffers. That is common knowledge.

    But when you are the last to disconnect (or deactivate) this can take a much longer time! Thinking about it it makes sence: all the dirty pages must be cleaned and after that the logs have to be archived.
    But the thing is:
    - 1 run my test scripts updating like a mad man: 2:30 minutes
    - 2 I leave the database idle for 30 minutes
    - 3 I deactivate the database: this takes more than 5 minutes !!

    I wonder: is there something I can do in that idle time start cleaning the buffer pools and archive log files? Some kind of: 'be prepared to close a.s.a.p.' command?

    P.S. I wish all you lucky b*st*rds travelling to Barcelona next week a good conference.
    I don't have a good answer to your question, but you can rest assure that I will enjoy Barcelona ;-) Do you have DB2_USE_ALTERNATE_PAGE_CLEANING=ON?
    --
    Lennart

  3. #3
    Join Date
    Jan 2009
    Location
    Zoetermeer, Holland
    Posts
    746
    Quote Originally Posted by lelle12 View Post
    Do you have DB2_USE_ALTERNATE_PAGE_CLEANING=ON?
    Thought about that but I seem to remember that this parameter is obsolete because it is default behaviour now. But I am not sure. Gonna test now.
    .
    .
    .
    Okay. No effect (seems even slower)
    Last edited by dr_te_z; 10-09-13 at 08:09.
    Somewhere between " too small" and " too large" lies the size that is just right.
    - Scott Hayes

  4. #4
    Join Date
    Jan 2009
    Location
    Zoetermeer, Holland
    Posts
    746
    Why ask you? Ask my friend Google:

    http://www.dbforums.com/db2/1654037-...fferpools.html
    But... the db2pdcfg line does not work on my 10.5 express-c

    IBM DB2 9.8 Information Center for Linux, UNIX, and Windows
    db2 flush bufferpool all Works!!

    I have to prepare a few 'hacmp' switches from 1 server to another. This seems like a good preperation for such a process. Now see what works on my 9.7.7. databases...
    -----
    Tried it on a 9.7.7 database on aix. The 'flush bufferpool all' is not known. The 'db2pdcfg -db sample -flushbp' seems to work. I could not do extensive tests there with timing the deactivate and so on, but the database did not go down
    Last edited by dr_te_z; 10-11-13 at 02:20. Reason: tried on 977@aix
    Somewhere between " too small" and " too large" lies the size that is just right.
    - Scott Hayes

  5. #5
    Join Date
    Aug 2008
    Location
    Toronto, Canada
    Posts
    2,367
    Quote Originally Posted by dr_te_z View Post
    Somewhere between " too small" and " too large" lies the size that is just right.
    Some women think size doesn't matter

  6. #6
    Join Date
    Jan 2009
    Location
    Zoetermeer, Holland
    Posts
    746
    Quote Originally Posted by db2girl View Post
    Some women think size doesn't matter
    Got that coming: I started the dirty talk about all those dirty pages...yek
    Somewhere between " too small" and " too large" lies the size that is just right.
    - Scott Hayes

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