Details
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Improvement
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Resolution: Fixed
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Major
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Morpheus
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1
Description
Currently, if an index scan is not covering, a fetch is done immediately after the index scan, and filters are evaluated after the fetch. There are situations where a filter cannot be effectively used to generate an index span, however the filter only depends on index keys and thus can potentially be evaluated with the index key values only. Such a filter can potentially discard result returned from the index scan and thus reduce unnecessary fetches.
Such filters can be something like:
lower(c1), when c1 is an index key
c1 LIKE "%abc%", like pattern with leading wild card
Attachments
Issue Links
- blocks
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MB-52254 [BP to 7.1.2] - Improve pagination queries with fetch
- Closed
- causes
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MB-51998 filter wrongly pushed on indexscan
- Resolved
- is a backport of
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MB-51817 Push filters to index scan to potentially reduce fetch size
- Resolved
- is triggering
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MB-54971 [BP to 7.2.0 MB-54952] - planner gives error and not considering other indexes
- Closed
For Gerrit Dashboard: MB-52253 | ||||||
---|---|---|---|---|---|---|
# | Subject | Branch | Project | Status | CR | V |
175291,2 | MB-52253 Push available filters to index scan to reduce fetch size | neo | query | Status: MERGED | +2 | +1 |
175639,3 | MB-52417 Retain covers from parent | master | query | Status: MERGED | +2 | +1 |
175661,2 | MB-52417 Retain covers from parent | neo | query | Status: MERGED | +2 | +1 |
188425,3 | MB-56039 Modify OR-clause handling | master | query | Status: MERGED | +2 | +1 |
188427,2 | MB-56039 Modify OR-clause handling | neo | query | Status: MERGED | +2 | +1 |
189184,2 | MB-56281 Modify OR-clause handling | cheshire-cat | query | Status: MERGED | +2 | +1 |
189957,4 | MB-53903 Proper setting of exact spans | master | query | Status: MERGED | +2 | +1 |
191063,2 | MB-56941 Modify OR-clause handling | 7.1.x | query | Status: MERGED | +2 | +1 |
191243,2 | MB-56563 Proper setting of exact spans | neo | query | Status: MERGED | +2 | +1 |
191247,2 | MB-56563 Proper setting of exact spans | 7.1.x | query | Status: MERGED | +2 | +1 |