Merge branch 'master' into ENG-3038-merge-join-code-paths
Merge remote-tracking branch 'alexeev/ENG-3038-merge-join-code-paths' into ENG-3038-merge-join-code-paths

Conflicts:
	tests/scripts/examples/sql_coverage/join-template.sql
ENG-4096: optimize query only with GROUP BY on indexed columns (no WHERE, ORDER BY) to use IndexScan instead of SeqScan; moreover, apply SerialAgg on this IndexScan if it's unique.
Prep for ENG-5135, improve some tests, rework VoltDB patches to hsql NumberType.
ENG-4096: add test cases; use ParsedColInfo not groupbyExprs in ParsedSelectStmt to find the right index.
ENG-4096: remove unique check and change cooresponding test cases
ENG-4096: remove unnecessary unique index in test ddl; only apply this optimization when needed.
Merge branch 'master' into ENG-4096
ENG-4096: changes based on Paul's review.
ENG-5135 Allow live widen of columns used in expression matviews. Cleanup AbstractExpression from JSON.
Merge branch 'master' into ENG-5135-live-expr-matview
restore a test table used in pro testing
Merge branch 'ENG-5135-prep' into ENG-5135-live-expr-matview
Merge branch 'master' into ENG-5135-live-expr-matview
Turn the multi outer join feature on
ENG-4625: use existing index only to speed up min/max maintainance; add indexForMinMax in MaterializedViewInfo catalog definition.
TODO: add more test cases when using indexes.
ENG-4625: a minor change
ENG-4625
ENG-4625: new ddl compiler and indexed min/max matview test cases.
ENG-3135-prep improve sqlcoverage UPDATE testing, remove outdated "regression" scripts.