Re: Question on number of blocks

The number of blocks is the maximum size your table data have occupied since you created the table or since you last trucated it or deallocated unused space if you did.
It is NOT the size of actual data in your table at the current time.

The number of empty blocks is the total size of your table's extents (physical total size allocated to your table in the datafile) minus the number of blocks as mentioned above. I.e, blocks that have NEVER been filled or that have been explicitly freed thrue a TRUNCATE TABLE or DEALLOCATE UNUSED statement.

Loading data with truncate option doesn't deallocate free space (in the sense of removing
empty blocks), it just analyzes the contents of the existing blocks and marks them as
empty if they are (i.e enables them to be freed at the next deallocation of free space).

Deallocating unused space actually doesn't free empty blocks, it frees empty extents.
If an extent is partially filled with data, it won't be freed. That's why tou still have empty
blocks after deallocating free space. Received on Wed Jun 24 1998 - 17:11:14 CDT