Re: I am confused re PCTFREE and PCTUSED...

PTCTFREE 20
PCTUSED 40 This means that 20% of each block is reserved for future updates: When the block gets filled(used) to 80%, the block is no longer a candidate for more inserts. However, as records get deleted from the block, the used space in the block decreases. As more records get deleted, the used space continues to drop. At this point, the block is still not a candidate for further insert. But, if the used space gets below PCTUSED, the block becomes available for new insert. This process repeats itself over and over again.

NOTE: that PCTUSED 40 means that if the used space within the block drops below this number, the block can permit inserts.

hope that helps wozi_at_dhc.net

NNOOR wrote in message <7ih2b7$ml8_at_chronicle.concentric.net>...
>Hi,
>
>Following is straight from Oracle documentation
>re: PCTFREE and PCTUSED: "After the free space in a data
>block reaches PCTFREE, no new rows are inserted in that
>block until the percentage of space used falls below PCTUSED."
>
>I am a little confused. Say that PCTFREE is 20 (default) and
>PCUSED is 40 (default). Does that mean, that any given time
>(assuming updates do not occur at a very high rate, and if
>they do, they do not change the data size significantly), the
>maximum space used in a block is only 40%?---20% is left free
>for updates, and data base will stop inserting rows into the
>block when it reaches 40% used. Am I drawing correct conclusions
>from the statement quoted above?
>
>Thanks and Regards,
>Nasir Noor (nnoor_at_cris.com)
Received on Wed May 26 1999 - 12:24:54 CDT