Question: what is pctfree and pctused in oracle?
Answer: PCTFREE and PCTUSED are the block storage parameters. PCTFREE- This parameter is used to specify how much space should be left in the block for updates. The default value is 10. For Eg, if The PctFree for a block is 30, then Oracle keeps on adding new rows to the block until the block is 70 % full.