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  1. Qt
  2. QTBUG-20658

[Performance] QSqlQuery::boundValues has unneeded O(n^2) complexity, can be O(n)

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: P2: Important
    • Resolution: Done
    • Affects Version/s: 4.7.3
    • Fix Version/s: 5.0.0 Beta 1, 5.0.0
    • Component/s: SQL Support
    • Labels:
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      Description

      For each bound value a call is made to QSqlResult::private->indexes.index(QHash.index, which is O(n)), which results in overall complexity of O(n^2).

      For ORMs that select records by a list of primary or foreign keys this can end up taking much longer than needed.

      Attached patch makes the call O(n).

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          Task - A task that needs to be done. QTBUG-25005 Critical issues for Qt5 Beta 1

          • P0: Blocker - MUST be fixed ASAP. This includes issues that prevent/block further Qt development; Legal issues & Serious data loss issues.
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              Assignee:
              zhongle honglei zhang
              Reporter:
              newellm Matthew Newell
              Votes:
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                Dates

                Created:
                Updated:
                Resolved:

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