1. 10 Feb, 2021 28 commits
  2. 09 Feb, 2021 1 commit
    • Vincent Pelletier's avatar
      CMFActivity: Simplify validation queries further. · e4273c58
      Vincent Pelletier authored
      The query planner does not seem to notice that we are trying to know if
      any row exists matching a set of dependency values, and it keeps scanning
      multiple row for each value - which is unproductive.
      So split dependency queries from (pseudo-code)
        WHERE <column{,s}> IN <values{, pairs}>
      to unions of
        WHERE <column{,s}> = <value{, pair}> LIMIT 1
      which produces query plans which do stop immediately when finding a
      candidate row.
      On a serialization_tag query with 40 values and real-world indexations,
      this reduces the number of rows scanned by mariadb from 500 (<10%
      efficiency) to 40 (100% efficiency).
      The produced SQL is significantly larger (~3x, around 500kB on
      real-world sample data, but may vary a lot depending on value length),
      but if this has any effect is is more than compensated by the improved
      query plan efficiency.
      e4273c58
  3. 08 Feb, 2021 3 commits
  4. 05 Feb, 2021 3 commits
  5. 04 Feb, 2021 5 commits