[jira] [Created] (CALCITE-2968) New AntiJoin relational expression

["Ruben Quesada Lopez (JIRA)" <ji...@apache.org>]

Ruben Quesada Lopez created CALCITE-2968:
--------------------------------------------

             Summary: New AntiJoin relational expression
                 Key: CALCITE-2968
                 URL: https://issues.apache.org/jira/browse/CALCITE-2968
             Project: Calcite
          Issue Type: New Feature
            Reporter: Ruben Quesada Lopez


The goal of this ticket is to follow the discussion started in CALCITE-2920 (and its [PR|https://github.com/apache/calcite/pull/1110]).

With the implementation of CALCITE-2920, RelBuilder has now a method to create an AntiJoin. However, since, for the moment, there is no "AntiJoin" expression, the only possibility to build an AntiJoin is using a LogicalCorrelate with SemiJoinType.ANTI, and that's exactly what this method does, for now.
The idea would be to "generalize" this with the creation of a new AntiJoin (a.k.a. AntiSemiJoin) relational expression.

Some ideas about how to implement it:
- Modify SemiJoin class: add a new instance field protected final SemiJoinType semiJoinType;, which will be by default SemiJoinType.SEMI (to ensure backwards compatibility); but that could also be SemiJoinType.ANTI, to represent an AntiJoin (a.k.a. AntiSemiJoin)
- We could easily have two implementations of Antijoin:
-- a) Enumerable: small modification in EnumerableSemiJoin and EnumerableSemiJoinRule in order to propagate the SemiJoinType, plus a new antiJoin method in EnumerableDefaults (basically the same as semiJoin method, but with a "not contains" predicate instead of "contains")
-- b) Correlate: small modification in JoinToCorrelateRule to propagate the SemiJoin.semiJoinType will suffice to create the appropriate LogicalCorrelate with type SEMI / ANTI
- RelBuilder antiJoin method would no longer create a LogicalCorrelate type=ANTI, but instead a SemiJoin type=ANTI (using a new method in SemiJoinFactory that would accept an additional SemiJoinType parameter).




--
This message was sent by Atlassian JIRA
(v7.6.3#76005)