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Re: Extent allocation for objects

From: <>
Date: Mon, 19 May 2003 13:12:05 -0800
Message-ID: <>

"alter table move" is not moving just the data, it's moving all blocks you have allocated, which is 512m worth.


Rick Stephenson <>
Sent by:
 05/19/2003 01:41 PM
 Please respond to ORACLE-L  

        To:     Multiple recipients of list ORACLE-L <>
        Subject:        Extent allocation for objects

Let me give you the scenarios. Maybe I can get a good explanation from someone.

Tablespace A locally managed uniform extents size 512M. Tablespace B locally managed uniforma extents size 1M.  

  1. Create table TabA tablespace A. Insert data, and it has 1 extent of 512M even though the table size is only 76M. This makes sense.
  2. Create table TabA tablespace B. Insert data, and it has 76 extents of 1M each. This makes sense.
  3. Create table TabA tablespace A. Same as scenario 1. Alter table TabA move tablespace B. Creates 512 extents of 1M each. Why? The table only needs 76M of space. Why create all those additional extents?

Thanks for any information,  

Rick Stephenson  

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