Good morning,

I'm happy to discuss with you regarding Datawarehousing, recently I have completed the course. I'm looking for real time ppl to help me regarding interview point of view.

Can anyone plz tell me the difference between B-tree index and bitmap index...

Why bitmap index is useful in Datawarehousing ?

Could anyone plz explain with example..

I'm looking fwd for ur reply..
thq..

NOTE : [This question was asked by harikrishna, I am posting it in proper forum]

Specify BITMAP to indicate that index is to be created with a bitmap for each distinct key, rather than indexing each row separately. Bitmap indexes store the rowids associated with a key value as a bitmap. Each bit in the bitmap corresponds to a possible rowid. If the bit is set, then it means that the row with the corresponding rowid contains the key value. The internal representation of bitmaps is best suited for applications with low levels of concurrent transactions, such as data warehousing.


CREATE BITMAP INDEX product_bm_ix
ON product_information_part(list_price)
TABLESPACE tbs_1
LOCAL(PARTITION ix_p1 TABLESPACE tbs_2,
PARTITION ix_p2,
PARTITION ix_p3 TABLESPACE tbs_3,
PARTITION ix_p4,
PARTITION ix_p5 TABLESPACE tbs_4 );