Details
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Improvement
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Resolution: Unresolved
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Major
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None
Description
When a prefix to be read is only present in a single sstable, it is wasteful to insert every entry to the hash table. The hash table insertion for dedup consumes significant CPU (20+%). See the attached CPU profile.
We can skip hash table insertion when the the entire prefix is read from a single sstable and no merge is required. This should improve performance in those cases.