[tjay83]

Hi
Does the emty_blocks column in the below query
show blocks above HWM or empty blocks below HWM


select table_name,a.blocks,b.bytes/1024 as KB,num_rows,empty_blocks
from user_tables a, user_segments b
where a.table_name = b.segment_name
and empty_blocks >0
order by empty_blocks desc

Table_name Blocks KB Num_rows Empty_blocks
------------------- --------- ----- ------------ ------------------
TEMPHISTORY 0 52224 0 6528

[anacedent]

>Does the emty_blocks column in the below query show blocks above HWM or empty blocks below HWM

No & you should run your own empirical test for obtaining correct answer.

Create a table.
Insert a bunch of rows.
commit;
delete half the rows.
run your query.

[tjay83]

alter table move clause works for blocks which are only below HWM
right?

[anacedent]

By definition all data within a table exists below the HWM.
So there is nothing to move above HWM.

Why the obsession with HWM; over which you have minimal or no control?

What SQL is used to obtain HWM for any table?

[tjay83]

but
shrink space command, reclaim space both below and above HWM

[anacedent]

Why the obsession with HWM; over which you have minimal or no control?

What SQL is used to obtain HWM for any table?

To what do you use HWM?
How does HWM relate to any Business Rule?