Examples of org.eigenbase.sql2rel.RelFieldTrimmer$TrimResult

org.eigenbase.sql2rel.RelFieldTrimmer

Result of an attempt to trim columns from a relational expression.

The mapping describes where to find the columns wanted by the parent of the current relational expression.

The mapping is a {@link org.eigenbase.util.mapping.Mappings.SourceMapping}, which means that no column can be used more than once, and some columns are not used. {@code columnsUsed.getSource(i)} returns the source of the i'th outputfield.

For example, consider the mapping for a relational expression that has 4 output columns but only two are being used. The mapping {2 → 1, 3 → 0} would give the following behavior:

columnsUsed.getSourceCount() returns 4
columnsUsed.getTargetCount() returns 2
columnsUsed.getSource(0) returns 3
columnsUsed.getSource(1) returns 2
columnsUsed.getSource(2) throws IndexOutOfBounds
columnsUsed.getTargetOpt(3) returns 0
columnsUsed.getTargetOpt(0) returns -1

          JoinRelBase.class, HiveFilterRel.DEFAULT_FILTER_FACTORY),
          // TODO: Enable it after OPTIQ-407 is fixed
          //RemoveTrivialProjectRule.INSTANCE,
          new HivePartitionPrunerRule(SemanticAnalyzer.this.conf));


      RelFieldTrimmer fieldTrimmer = new RelFieldTrimmer(null, HiveProjectRel.DEFAULT_PROJECT_FACTORY,
          HiveFilterRel.DEFAULT_FILTER_FACTORY, HiveJoinRel.HIVE_JOIN_FACTORY, RelFactories.DEFAULT_SEMI_JOIN_FACTORY,
          HiveSortRel.HIVE_SORT_REL_FACTORY, HiveAggregateRel.HIVE_AGGR_REL_FACTORY, HiveUnionRel.UNION_REL_FACTORY);
      basePlan = fieldTrimmer.trim(basePlan);


      basePlan = hepPlan(basePlan, true, mdProvider,
          new PushFilterPastProjectRule(FilterRelBase.class,
              HiveFilterRel.DEFAULT_FILTER_FACTORY, HiveProjectRel.class,
              HiveProjectRel.DEFAULT_PROJECT_FACTORY));

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Examples of org.eigenbase.sql2rel.RelFieldTrimmer$TrimResult

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