Bitmap Indexes are described here, but I don't understand some part of it. A plain indexscan fetches one tuple-pointer at a time from the index, and immediately visits that tuple in the table. ...
For doing a simple equality query such as EXPLAIN SELECT * FROM table where x = 1; I see that a Bitmap Index scan is done using the BTree indexes. Apparently, Bitmap Index scans disable Hash ...
If I have a database of employees and expected queries on (salary,gender). Would it be a good idea to have a B+ tree index on salary and Bitmap index on gender at every leaf node of a tree. What are ...
Please clarify the difference between BitMap Index and Btree index. I am using mysql version 5.5.37-0ubuntu0.12.04.1. I can able to create Btree index but unable to create the same, Please find the ...
I have database named "demo_dev" database and added a table named "countries". I wanted to create bitmap index on a column say region as it has less unique values using following query. CREATE ...
A good early paper on the topic of bitmap indexes is "Bit Transposed Files" by Wong et al, published in 1985. In all the query-decoding examples, it is left to the reader to understand how each ...
The Oracle documentation includes the following advice: A bitmap index should be built on each of the foreign key columns of the fact table or tables In that reference, there is even a bitmap ...