remove the column of big table
alter table tt set unused column age;alter table tt drop unused column;
oracle rowid detail
the following is my practise based on warehose's rowidselect u.rowid from knta_users u where u.username='admin';A-Z (0-25),a-z(26-51),0-9(52-61),+(62),/(63)AAATDT---object_id 19*power(64,2)+3*64+19...