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Ruben Q L edited comment on CALCITE-4094 at 6/30/20, 7:55 AM: -------------------------------------------------------------- [~danny0405] the idea is having always the default policy {{Strong.Policy.AS_IS}} (so it will remain backwards compatible, the one who writes the udf does not need to specify it); but add mechanism (I guess another constructor in {{SqlUserDefinedFunction.java}}) so that we can specify a different policy value. was (Author: rubenql): [~danny0405] the idea is having always the default policy {{Strong.Policy.AS_IS}} (so it will remain backwards compatible, the one who writes the udf does not need to specify it); but add mechanism (I guess another constructor) so that we can specify a different policy value. > Allow SqlUserDefinedFunction to define an optional Strong.Policy > ---------------------------------------------------------------- > > Key: CALCITE-4094 > URL: https://issues.apache.org/jira/browse/CALCITE-4094 > Project: Calcite > Issue Type: Improvement > Components: core > Reporter: Ruben Q L > Assignee: Ruben Q L > Priority: Major > > {{FilterJoinRule}} performs some optimizations based on > {{RelOptUitl#simplifyJoin}}. Specifically, this part of the code: > {code} > if (joinType.generatesNullsOnRight() > && Strong.isNotTrue(filter, rightBitmap)) { > joinType = joinType.cancelNullsOnRight(); > } > {code} > allows e.g. a LEFT join with a condition on its RHS to be transformed into an > INNER join, with the condition pushed on its right input. > In order to achieve this, the utility class {{Strong}} defines a certain > {{Policy}} map, depending on the {{SqlKind}} of a {{RexNode}} (i.e. depending > on the filter condition). In case of operators such as {{EQUALS}}, > {{NOT_EQUALS}}, {{LESS_THAN}}, etc, it defines {{Policy.ANY}} (i.e. > expression is null if and only if at least one of its arguments is null). In > case of a left join with conditions with this policy on the right-hand-side, > the join gets simplified by this module because of the nullability of the > right columns. However, in the case of {{SqlUserDefinedFunction}} the policy > is the default {{Policy.AS_IS}}, which prevents the simplification from > happening. > It is proposed to enrich {{SqlUserDefinedFunction}} with an optional > {{Strong.Policy}}, and adapt {{Strong#isNull}} so that these functions can > also benefit from this simplification. -- This message was sent by Atlassian Jira (v8.3.4#803005)