Interface FlinkMetadata.UniqueGroups
- All Superinterfaces:
org.apache.calcite.rel.metadata.Metadata
- Enclosing class:
- FlinkMetadata
public static interface FlinkMetadata.UniqueGroups
extends org.apache.calcite.rel.metadata.Metadata
Metadata about the (minimum) unique groups of the given columns from a specified relational
expression.
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Nested Class Summary
Nested ClassesModifier and TypeInterfaceDescriptionstatic interfaceHandler API. -
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final org.apache.calcite.rel.metadata.MetadataDef<FlinkMetadata.UniqueGroups>static final Method -
Method Summary
Modifier and TypeMethodDescriptionorg.apache.calcite.util.ImmutableBitSetgetUniqueGroups(org.apache.calcite.util.ImmutableBitSet columns) Returns the (minimum) unique groups of the given columns from a specified relational expression.Methods inherited from interface org.apache.calcite.rel.metadata.Metadata
rel
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Field Details
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METHOD
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DEF
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Method Details
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getUniqueGroups
org.apache.calcite.util.ImmutableBitSet getUniqueGroups(org.apache.calcite.util.ImmutableBitSet columns) Returns the (minimum) unique groups of the given columns from a specified relational expression.- Parameters:
columns- the given columns in a specified relational expression. The given columns should not be null.- Returns:
- the (minimum) unique columns which should be a sub-collection of the given columns, and should not be null or empty. If none unique columns can be found, return the given columns.
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