Package org.apache.calcite.rel.metadata
Interface BuiltInMetadata.Distribution
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- All Superinterfaces:
Metadata
- All Known Subinterfaces:
BuiltInMetadata.All
- Enclosing class:
- BuiltInMetadata
public static interface BuiltInMetadata.Distribution extends Metadata
Metadata about how a relational expression is distributed.If you are an operator consuming a relational expression, which subset of the rows are you seeing? You might be seeing all of them (BROADCAST or SINGLETON), only those whose key column values have a particular hash code (HASH) or only those whose column values have particular values or ranges of values (RANGE).
When a relational expression is partitioned, it is often partitioned among nodes, but it may be partitioned among threads running on the same node.
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Nested Class Summary
Nested Classes Modifier and Type Interface Description static interface
BuiltInMetadata.Distribution.Handler
Handler API.
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Field Summary
Fields Modifier and Type Field Description static MetadataDef<BuiltInMetadata.Distribution>
DEF
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description RelDistribution
distribution()
Determines how the rows are distributed.
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Field Detail
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DEF
static final MetadataDef<BuiltInMetadata.Distribution> DEF
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Method Detail
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distribution
RelDistribution distribution()
Determines how the rows are distributed.
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