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  1. MariaDB Server
  2. MDEV-4120

UNIQUE indexes should not be considered for loose index scan

        Details

        • Type: Task
        • Status: Closed
        • Priority: Minor
        • Resolution: Fixed
        • Fix Version/s: 10.0.5
        • Component/s: None
        • Labels:
          None

          Description

          Currently the loose scan code in opt_range.cc considers all indexes as possible for the access method. Due to inexact statistics it may happen that a loose scan is selected over a unique index.

          This is clearly wrong since a "loose scan" over a unique index will read the same keys as a direct index scan, but the loose scan has more overhead.

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                relates to

                Bug - A problem which impairs or prevents the functions of the product. MDEV-7118 Anemometer stop working after upgrade to from 5.6 to 10.0

                • Critical - Crashes, loss of data, severe memory leak.
                • Closed

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                  timour Timour Katchaounov added a comment -

                  Assigned to SergeyP for review.

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                  timour Timour Katchaounov added a comment - Assigned to SergeyP for review.
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                  psergey Sergei Petrunia added a comment -

                  Patch approved with comments (see email)

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                  psergey Sergei Petrunia added a comment - Patch approved with comments (see email)

                    People

                    • Assignee:
                      timour Timour Katchaounov
                      Reporter:
                      timour Timour Katchaounov
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