[CALCITE-1627] Statistics.of() instance doesn't acknowledge super sets of keys

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Invalid
• Fix Version/s: 1.12.0
• Component/s: core
• Assignee: Julian Hyde
• Reporter: Jess Balint
• Created: 09/Feb/17 17:26
• Updated: 24/Mar/17 03:20
• Resolved: 09/Feb/17 17:58

Description

The default instance of Statistic returned by Statistics.of() doesn't acknowledge keys which contain other keys.

      public boolean isKey(ImmutableBitSet columns) {
        for (ImmutableBitSet key : keys) {
          if (columns.contains(key)) {
            return true;
          }
        }
        return false;
      }

This test should also return true for bit sets which subsume a key, e.g. if A is a key then AB is also a key.