Do we need to truncate a large table before dumping it?

Question

it says that we should always crop a large table before dumping it, this improves performance. It's true?

Answer 1

IMO in general, if you just want to drop the table then it DROPfits. It will free up space just like it TRUNCATEwill and will have the advantage of atomic space (no query will be able to see the table "empty").

From 10g +, the deleted table will not be deleted immediately: if there is enough space, it will be placed in the trash. If you crop the table first, there will be no data left in the basket. Maybe that's why you were told to truncate first (?).

, , DROP TABLE your_table PURGE, .

Answer 2

, , - .

, .

, . , , , .

Answer 3

It might be a good idea to reset the high water mark.