Dear all,
I want to pour some questions on the above topic questions :

1. I come across a statement saying that PCTUSED Parameter explanation - After a data block becomes full, as determined by PCTFREE, Oracle does not consider the block for the insertion of new rows until the percentage of the block being used falls below the parameter PCTUSED. Before this value is archived, Oracle uses the free space of the data block only for updates to rows already contained in the data block.

Q : What is the reason for this - PCTUSED ? Why they want to control that parameter ? Can I set it to 0 ?

Q: Is free list this pre-allocated ? Is this only use for PCTFREE ? Where does it store ?

Your answer is very much appreciated. Thanks.