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5
votes
2answers
1k views

Cardinality rule for bitmap indexes

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 ...
4
votes
0answers
153 views

How to decode a query on a composite unary-encoded attribute?

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 ...
0
votes
1answer
307 views

ON creating BITMAP INDEX on a table in mysql throws error

say, 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 ...
-1
votes
1answer
83 views

Btree index and Bit Map Index [duplicate]

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 ...