Question: what is pctfree and pctused setting?
Answer: PCTFREE, PCTUSED, and Row Chaining. For manually managed tablespaces, two space management parameters, PCTFREE and PCTUSED , enable you to control the use of free space for inserts and updates to the rows in all the data blocks of a particular segment. ... They do not use the PCTFREE storage parameter or free lists.