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Bitmap Index [message #359036] Thu, 13 November 2008 07:36 Go to next message
rajput.anshu
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I seen in oracle complete reference book that "Bitmap index is a type of index which is best suited for columns with few distinct values".If column have few distinct values and frequently used as a limiting condition(where clause) in queries then we should use a bitmap index.....But i didn't understand that how it work fast in that query or how it works. Please help me to understand Bitmap index.
Re: Bitmap Index [message #359039 is a reply to message #359036] Thu, 13 November 2008 07:42 Go to previous messageGo to next message
Michel Cadot
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Database Performance Tuning Guide
Chapter 15 Using Indexes and Clusters
Section 15.5 Using Bitmap Indexes for Performance

Regards
Michel
Re: Bitmap Index [message #359042 is a reply to message #359039] Thu, 13 November 2008 07:59 Go to previous messageGo to next message
rajput.anshu
Messages: 45
Registered: October 2008
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I seen there but it is too complex...Please will u explain or give some important points when we use bitmap index.
Re: Bitmap Index [message #359043 is a reply to message #359042] Thu, 13 November 2008 08:01 Go to previous messageGo to next message
joy_division
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You question in the first message answers this question.
Re: Bitmap Index [message #359044 is a reply to message #359042] Thu, 13 November 2008 08:01 Go to previous messageGo to next message
Michel Cadot
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This section contains a summary of 6 lines, how could we say more in less words?
If it is too complex for you forget bitmap index.

Regards
Michel
Re: Bitmap Index [message #359049 is a reply to message #359044] Thu, 13 November 2008 08:25 Go to previous message
S.Rajaram
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Registered: October 2006
Location: United Kingdom
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May be this could help you out.

http://en.wikipedia.org/wiki/Bitmap_index

Also check this article about comparison of bitmap index with btree index.

http://www.oracle.com/technology/pub/articles/sharma_indexes.html

Regards

Raj

[Updated on: Thu, 13 November 2008 08:27]

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