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  1. Couchbase Server
  2. MB-52253

[BP to 7.1.2] - Push filters to index scan to potentially reduce fetch size

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    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

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          blocks

          Improvement - An improvement or enhancement to an existing feature or task. MB-52254 [BP to 7.1.2] - Improve pagination queries with fetch

          • Major - Major loss of function.
          • Closed
          causes

          Bug - A problem which impairs or prevents the functions of the product. MB-51998 filter wrongly pushed on indexscan

          • Major - Major loss of function.
          • Resolved
          is a backport of

          Improvement - An improvement or enhancement to an existing feature or task. MB-51817 Push filters to index scan to potentially reduce fetch size

          • Major - Major loss of function.
          • Resolved
          is triggering

          Bug - A problem which impairs or prevents the functions of the product. MB-54971 [BP to 7.2.0 MB-54952] - planner gives error and not considering other indexes

          • Major - Major loss of function.
          • Closed
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              ajay.bhullar Ajay Bhullar
              bingjie.miao Bingjie Miao
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                Created:
                Updated:
                Resolved:

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