I myself am always confused and have to think about pctfree and pctused.
Pctfree takes the block off of the free list, and pctused puts it back
on the free list. (I think, I could be confused and have gotten it
backwards). So it makes complete sense that while it is 70% full you
can add rows to it, because you pctfree is set to 20. When you get to
80% full then that block will be taken off the free list UNTIL by
deleting rows or what ever you reach the 50% mark when it is put back on
the free list until it reaches 80% full and it is taken off again.
I hope this helps,
Glen Upreti
glen.upreti_at_nau.edu
Zhenming Wang wrote:
>
> I have a confusion about the two PCTFREE and PCTUSED parameters. For
> example, when the PCTFREE is set 20, and the PCTUSED is set 50, according to
> their definitions, I can insert rows unitil the block is 80% full because
> the remaining 20% is kept for updating for the rows in the block. Following
> I did some upgrading, which consumed some storage, let's say now the block
> is 90% full. I know I can't insert any rows at this level, so I deleated
> some rows, now the rows in the block take 30% of the block's total capacity.
> So according to the PCTUSED definition(below PCTUSED 50), I can insert new
> rows into the block. My question is: After I inserted some rows and did
> some upgrading, the block is now 70%. At this level, Can I continue to
> insert new rows into the block until it reaches 80%? It seems I can, because
> the block has not reached the 80%. But According to the PCDUSED, you cannot.
> You have to wait until you do some deleating rows until the block is below
> the PCTUSED 50. Because if I can insert new rows at a level higher than
> PCTUSED but below the 80% full, why I need the PCTUSED value? At this point,
> the two parameters seem contradict, as one say you can insert your rows
> until you reach 80%, another say you can't, because you are not below 50%
> you set for the PCTUSED.
> Zhenming
>
> zmwang_at_thenew.net
Received on Fri Aug 21 1998 - 09:44:05 CDT
