Question on number of blocks

Hi All,

    I have question on number of blocks and free blocks of a table. I have table of 160 rows. I analyzed the table and got the following stats

Number of Rows: 160
Blocks: 65
Empty Blocks: 14

Then I reloaded the data using sqlldr in DIRECT mode with replace option. Then I analyzed the
table again. The stats I got was:

Number of Rows: 160
Blocks: 75
Empty Blocks: 4

Then I reloaded the data using sqlldr in DIRECT mode with truncate option. Then I analyzed the
table again. The stats I got was:

Number of Rows: 160

Blocks:               10
Empty Blocks:     69

Then I deallocated unused space using

alter table tablea deallocate unused space; Then I analyzed the table again. The stats I got was:

Number of Rows: 160

Blocks:               10
Empty Blocks:     29

Documentation says that 'deallocate unused space' clause frees empty blocks over HWM. If so what is the HWM for this table? It looks like data actually occupies 10 blocks only. But 1st 2 cases 'blocks' column shows a large number. What is the correlation between blocks and empty blocks? Can someone explain it?

Thanks

raghuvir Received on Wed Jun 24 1998 - 09:57:08 CDT