Hwm
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Thread: Hwm

  1. #1
    Join Date
    Nov 2003
    Posts
    89

    Hwm

    HI,

    My table has following below details

    [CODE]
    Free Blocks.............................3
    Total Blocks............................943
    Total Bytes.............................7725056
    Unused Blocks...........................3
    Unused Bytes............................24576
    Last Used Ext FileId....................58
    Last Used Ext BlockId...................165595
    Last Used Block.........................300
    [/CODE}

    1) I see there are total 943 blocks but used are 300 and unsed are 3 blocks and free are 3 blocks
    Total is 306 blocks. Where are the remaining blocks in the table.
    I assume when it does full table scan it reads till 640 blocks.
    To set my HWM i need to tuncate or move the table. Is there any other way I can make my HWM come to the blocks used.

    2) I did use deallocate unused keep command to free the blocks, but i see still the free blocks in the table. I had 20 free blocks and came up to 3 free blocks . but it does not go down from 3 to 1.
    Does HWM come down if free blocks reduce or it stays at the total used blocks ?

  2. #2
    Join Date
    May 2000
    Location
    ATLANTA, GA, USA
    Posts
    3,135
    What is your oracle release?

    Tamil

  3. #3
    Join Date
    Nov 2003
    Posts
    89
    Oracle 8.1.7.4

  4. #4
    Join Date
    May 2000
    Location
    ATLANTA, GA, USA
    Posts
    3,135
    In 8i, you have limited options- exp,drop nad imp or move.

    But why do you bother 340 blcoks extra read during FTS?.

    Tamil

  5. #5
    Join Date
    Nov 2000
    Location
    Pittsburgh, PA
    Posts
    4,001
    If you have an 8k block size your table would be less than 3 megs. If you are that concerned move the table. But if you keep inserting and deleting rows you might get back to a situation where you are wasting a few blocks. Besides a table like that is probably cached anyway.

    Code:
    alter table mytable move ONLINE tablespace newtablespace;
    alter table mytable move ONLINE tablespace oldtablespace;
    this space intentionally left blank

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