Oracle
From Alessandro's Wiki
- check stats enabled:
SELECT DBMS_STATS.get_prefs('PUBLISH') FROM dual;
- list of tables ordered by size
select segment_name,segment_type,bytes ,max_size from user_segments ORDER BY bytes DESC
- disable constraint
alter table table_name disable constraint <constraint>;
- enable constraint
alter table table_name enable constraint <constraint>;
- empty table and release space
truncate table table_name DROP STORAGE;
