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  1. #1
    Join Date
    Sep 2003
    Posts
    14

    Unanswered: tablespace creation with different pagesizes

    hi,
    I have a tablespace with pagesize of 4k which contains a table.Each record of this table is almost of 4k size.I am creating a new tablespace with pagesize 8k.NOw if i shift the contents of the old table to the new table will two 4k pages fit into a single 8k page?What should be done..
    I am creating an SMS tablespace....

    And one more thing...If i have many containers in a single tablespace will that improve the performance, even if i have a single hard disk.....


    thanx,
    deepak

  2. #2
    Join Date
    May 2003
    Location
    USA
    Posts
    5,737
    Yes, two rows will fit in the 8K page if the row size is slightly less than 4K and it fit on a 4K page previously.

    Not sure what your question is about “what should be done?” I would create a new tablespace, and then a new table (with a new name), then move the data with a insert/select, then drop the old table, then rename the new table to what the old table was. But there are other options such as doing an export/import of data. Don’t forget to look at your 8K bufferpool size since the 8K page will be using it.

    Having multiple containers can enable parallel operations (even if you don't have EEE or ESE partitioned tablespaces), assuming that the right parms for the database are set. This would be most helpful in situations where a tablespace scan is required for the SQL statement.

    But as you suspected, this can cause a lot of throughput issues if all containers are on the same disk, and limit the benefits achieved, or even possibly make things worse. This gets into disk and controller hardware issues that may vary somewhat depending on the type of disk subsystem used (IDE, Serial IDE, SCSI, etc).

  3. #3
    Join Date
    Sep 2003
    Posts
    14
    hi,

    Thanks Marcus.That was what i wanted to know....

    bye,
    deepak

    Originally posted by Marcus_A
    Yes, two rows will fit in the 8K page if the row size is slightly less than 4K and it fit on a 4K page previously.

    Not sure what your question is about “what should be done?” I would create a new tablespace, and then a new table (with a new name), then move the data with a insert/select, then drop the old table, then rename the new table to what the old table was. But there are other options such as doing an export/import of data. Don’t forget to look at your 8K bufferpool size since the 8K page will be using it.

    Having multiple containers can enable parallel operations (even if you don't have EEE or ESE partitioned tablespaces), assuming that the right parms for the database are set. This would be most helpful in situations where a tablespace scan is required for the SQL statement.

    But as you suspected, this can cause a lot of throughput issues if all containers are on the same disk, and limit the benefits achieved, or even possibly make things worse. This gets into disk and controller hardware issues that may vary somewhat depending on the type of disk subsystem used (IDE, Serial IDE, SCSI, etc).

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