DBAsupport.com Forums - Powered by vBulletin
Results 1 to 6 of 6

Thread: pctincrease set to 1 and auto-coalesce

  1. #1
    Join Date
    Dec 2001
    Posts
    141

    Question

    Hi everybody !
    I heard that the pctincrease tablespace's default parameter has to be set to 1% to force SMON process to coalesce free extent.
    Is that always true in 8.1.7 release ?
    Can I trust this rule ?
    Thanks a lot in advance.
    Helene

  2. #2
    Join Date
    Aug 2002
    Location
    Bangalore, India
    Posts
    405

    Cool

    To be precise, we should set the pctincrease value greater than 0 to enable auto coalesce by SMON. But, the problem in setting pctincrease to nonzero value is uncontrolled growth of segments and size of extents. So, to trade off between nice extent size and auto coalesce, we are setting pctincrease to 1.

    -nagarjuna

  3. #3
    Join Date
    Feb 2000
    Location
    Singapore
    Posts
    1,758
    Move on to LMT and stop worrying about fragmentation.

    Sanjay

  4. #4
    Join Date
    Feb 2000
    Location
    Washington DC
    Posts
    1,843
    Originally posted by nagarjuna
    To be precise, we should set the pctincrease value greater than 0 to enable auto coalesce by SMON. But, the problem in setting pctincrease to nonzero value is uncontrolled growth of segments and size of extents. So, to trade off between nice extent size and auto coalesce, we are setting pctincrease to 1.
    Its is uneven distribution of different extent sizes on the tablespace. But, not as such uncontrolled growth, Unless you have few thousands of extents. Its just 1% increase. If its 20%+ increase, thats TRUE...
    Reddy,Sam

  5. #5
    Join Date
    Aug 2002
    Location
    Bangalore, India
    Posts
    405
    Originally posted by sreddy
    Originally posted by nagarjuna
    To be precise, we should set the pctincrease value greater than 0 to enable auto coalesce by SMON. But, the problem in setting pctincrease to nonzero value is uncontrolled growth of segments and size of extents. So, to trade off between nice extent size and auto coalesce, we are setting pctincrease to 1.
    Its is uneven distribution of different extent sizes on the tablespace. But, not as such uncontrolled growth, Unless you have few thousands of extents. Its just 1% increase. If its 20%+ increase, thats TRUE...
    I had default value of 50% in my mind when I said that..

    -nagarjuna

  6. #6
    Join Date
    Jun 2002
    Posts
    73

    Talking

    You don't worry about pctincrease problem. I suggest that u keep your pctincrease to zero as higher pctincrease lead to uncontrollable growth, You just have to run a command after 1 week or so.

    SQL>ALTER TABLESPACE tablespace_mame COALESCE;

    I think by this way you will be on safe side.
    You cannot succeed if you fear to face challenges.
    MAS
    BE(CS) , OCP 8/8i.



Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


Click Here to Expand Forum to Full Width