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When two index scan's AND'ed pass first bitmap into second scan and set bit in second bitmap only if corresponding bit is set in first bitmap.
Then no need to perform AND operation on both bitmap's as second already ANDed with first one
This is reduced number operation on bitmaps and amount of memory needed for second bitmap
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Description
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When two index scan's AND'ed pass first bitmap into second scan and set bit in second bitmap only if corresponding bit is set in first bitmap.
Then no need to perform AND operation on both bitmap's as second already ANDed with first one
This is reduced number operation on bitmaps and amount of memory needed for second bitmap |
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Improvement
Closed
Major
Optimize index scan when more than one index scanned and ANDed
directly in it for hits in the second index.