Package org.apache.calcite.rel.core
Class Union
java.lang.Object
org.apache.calcite.rel.AbstractRelNode
org.apache.calcite.rel.core.SetOp
org.apache.calcite.rel.core.Union
- All Implemented Interfaces:
Cloneable
,RelOptNode
,RelNode
- Direct Known Subclasses:
Bindables.BindableUnion
,EnumerableUnion
,JdbcRules.JdbcUnion
,LogicalUnion
public abstract class Union extends SetOp
Relational expression that returns the union of the rows of its inputs,
optionally eliminating duplicates.
Corresponds to SQL UNION
and UNION ALL
.
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Nested Class Summary
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Field Summary
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Constructor Summary
Constructors Modifier Constructor Description protected
Union(RelOptCluster cluster, RelTraitSet traits, List<RelNode> inputs, boolean all)
protected
Union(RelInput input)
Creates a Union by parsing serialized output. -
Method Summary
Modifier and Type Method Description double
estimateRowCount(RelMetadataQuery mq)
Returns an estimate of the number of rows this relational expression will return.static double
estimateRowCount(RelNode rel)
Deprecated.Methods inherited from class org.apache.calcite.rel.core.SetOp
copy, copy, deriveRowType, explainTerms, getInputs, isHomogeneous, replaceInput
Methods inherited from class org.apache.calcite.rel.AbstractRelNode
accept, accept, childrenAccept, collectVariablesSet, collectVariablesUsed, computeSelfCost, deepEquals, deepHashCode, equals, explain, getCluster, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getRelDigest, getRelTypeName, getRowType, getTable, getTraitSet, getVariablesSet, hashCode, isEnforcer, isValid, metadata, onRegister, recomputeDigest, register, sole, toString
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Constructor Details
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Method Details
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estimateRowCount
Description copied from interface:RelNode
Returns an estimate of the number of rows this relational expression will return.NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use
RelMetadataQuery.getRowCount(org.apache.calcite.rel.RelNode)
, which gives plugins a chance to override the rel's default ideas about row count.- Specified by:
estimateRowCount
in interfaceRelNode
- Overrides:
estimateRowCount
in classAbstractRelNode
- Parameters:
mq
- Metadata query- Returns:
- Estimate of the number of rows this relational expression will return
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estimateRowCount
Deprecated.
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