A high blevel on a bitmap can often suggest that a
reasonable amount of dml is occurring on the
underlying table which is pretty much a no-no.
bitmaps are very prone to ballooning in size wildly
when lots of dml is applied.
Jonathan Lewis showed me a test case where a table
with just a few
I used to preach the same rules of thumb: If blevel 4, if average filling
of leaf blocks 50, etc., etc. These days, as I become older and older
and more and more bitter, I'm inclined to say: If you're having a problem
with a SQL statement or a business function or a report or whatever - and
Govind,
Large indexes would tend to be 'taller'. However, I believe you can achieve
a flatter structure for the same index by using a larger block size. If you
are on 9i (any release?) then you could probably create new tablespaces with
larger blocksizes and recreating these indexes therein. Not
According tooracle documentation or metalink
sources,if the BLEVEL were to be more
than 4, it is recommended to rebuild the index.
select index_name,
blevel,decode(blevel,0,'OK BLEVEL',1,'OK BLEVEL', 2,'OK BLEVEL',3,'OK
BLEVEL',4,'OK BLEVEL','BLEVEL HIGH') OKfrom dba_indexeswhere
