Re: Why is PCTUSED not used for index?

Dino Hsu wrote:
>
> Dear all,
>
> Quoting a book,
> "...Finally, pctused is not used in index definitions. Since all items
> in an index must be in the right order for the index to work, Oracle
> must put an index entry into a block, no matter what. Thus, pctused is
> not used."
>
> In my visulization of a block, if some data row or index entry is
> removed from a block, the upper part of data or index in the block
> moves down to fill the gap, thus moves closer to the pctused position.
> I don't why an index block behaves differently than a data block.
> Anyone explains this? Thanks in advance.
>
> Dino

Because things are stored in order, then the only time space could be reused if a value that was previously deleted is reinserted, or all the entries in a block are removed - at which point the entire block becomes re-available - thus obviating the need for a pctused concept.

hth
connor

-- 
==============================
Connor McDonald

http://www.oracledba.co.uk

"Some days you're the pigeon, some days you're the statue..."