dba_tables: empty_blocks/(blocks+empty_blocks)<0.1% analyze table t compute statistics -> get empty_blocks truncate init hwm package:dbms_space recover space:export and import,alter table move ,alter table t deallocate unused oltp:small block size ,olap:large block size detect migration and chaining use analyze and statspack eliminating m & c:export and import,alter table move,copy migrate rows monitor index: rebuild(del_lf_rows/lf_rows_len>20%),coalesce
