Re: BLEVEL on bit-mapped indexes

2002-12-12 Thread Connor McDonald
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

Re: BLEVEL on bit-mapped indexes

2002-12-10 Thread Mogens Nørgaard
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

RE: BLEVEL on bit-mapped indexes

2002-12-10 Thread John Kanagaraj
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

RE: BLEVEL on bit-mapped indexes

2002-12-09 Thread Govind.Arumugam
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