RE: Actual space used per table

  • From: "Christian Antognini" <Christian.Antognini@xxxxxxxxxxxx>
  • To: <ranko.mosic@xxxxxxxxx>
  • Date: Fri, 2 Sep 2005 20:18:41 +0200


>Where is the rest ?

It depends... some possibilities are...

First. From the 8 blocks you should remove the header blocks (i.e. header 
block, free list blocks, ASSM header blocks and extent map blocks). If you use 
free list management at least 1. If you use ASSM at least 3.

Second. If you have deleted rows, more than PCTFREE free space is available in 
the blocks.

Third. If you have multiple free lists or ASSM *and* you didn't insert the data 
with a single session, the inserts were probably spread over many blocks. 
Therefore the blocks are not full.

Forth. Each block contains, for its internal management, different structures. 
You should remove at least 100-150 bytes per block. If you specified many ITLs 
this can be much more...

Fifth. I don't remember right now... but there are for sure other possibilities 


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