Package org.apache.calcite.rel.metadata

Class RelMdUniqueKeys

java.lang.Object

org.apache.calcite.rel.metadata.RelMdUniqueKeys

All Implemented Interfaces:

MetadataHandler<BuiltInMetadata.UniqueKeys>

public class RelMdUniqueKeys
extends Object
implements MetadataHandler<BuiltInMetadata.UniqueKeys>

RelMdUniqueKeys supplies a default implementation of RelMetadataQuery.getUniqueKeys(org.apache.calcite.rel.RelNode) for the standard logical algebra. The number of returned keys for each relational expression is bounded by a limit. The limit is used to restrict the exponential logic that can appear for certain query patterns and lead to CPU/memory exhaustion and crashes.

Field Summary

Fields

Modifier and Type	Field	Description
static final RelMetadataProvider	SOURCE

Constructor Summary

Constructors

Constructor	Description
RelMdUniqueKeys()	Creates a metadata handler for unique keys with the default limit.
RelMdUniqueKeys(int limit)	Creates a metadata handler for unique keys with the specified limit.

Method Summary

Modifier and Type	Method	Description
MetadataDef<BuiltInMetadata.UniqueKeys>	getDef()
Set<ImmutableBitSet>	getUniqueKeys(Aggregate rel, RelMetadataQuery mq, boolean ignoreNulls)
@Nullable Set<ImmutableBitSet>	getUniqueKeys(Calc rel, RelMetadataQuery mq, boolean ignoreNulls)
@Nullable Set<ImmutableBitSet>	getUniqueKeys(Correlate rel, RelMetadataQuery mq, boolean ignoreNulls)
@Nullable Set<ImmutableBitSet>	getUniqueKeys(Filter rel, RelMetadataQuery mq, boolean ignoreNulls)
Set<ImmutableBitSet>	getUniqueKeys(Intersect rel, RelMetadataQuery mq, boolean ignoreNulls)	Any unique key of any input of Intersect is an unique key of the Intersect.
@Nullable Set<ImmutableBitSet>	getUniqueKeys(Join rel, RelMetadataQuery mq, boolean ignoreNulls)
Set<ImmutableBitSet>	getUniqueKeys(Minus rel, RelMetadataQuery mq, boolean ignoreNulls)	The unique keys of Minus are precisely the unique keys of its first input.
Set<ImmutableBitSet>	getUniqueKeys(Project rel, RelMetadataQuery mq, boolean ignoreNulls)
@Nullable Set<ImmutableBitSet>	getUniqueKeys(Sort rel, RelMetadataQuery mq, boolean ignoreNulls)
@Nullable Set<ImmutableBitSet>	getUniqueKeys(TableModify rel, RelMetadataQuery mq, boolean ignoreNulls)
@Nullable Set<ImmutableBitSet>	getUniqueKeys(TableScan rel, RelMetadataQuery mq, boolean ignoreNulls)
Set<ImmutableBitSet>	getUniqueKeys(Union rel, RelMetadataQuery mq, boolean ignoreNulls)
@Nullable Set<ImmutableBitSet>	getUniqueKeys(Values rel, RelMetadataQuery mq, boolean ignoreNulls)
@Nullable Set<ImmutableBitSet>	getUniqueKeys(RelNode rel, RelMetadataQuery mq, boolean ignoreNulls)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

SOURCE

public static final RelMetadataProvider SOURCE

Constructor Details

RelMdUniqueKeys

public RelMdUniqueKeys()

Creates a metadata handler for unique keys with the default limit.

RelMdUniqueKeys

public RelMdUniqueKeys(int limit)

Creates a metadata handler for unique keys with the specified limit.

Parameters:

limit - a non-negative integer that bounds the number of unique keys returned for each relational expression.

Method Details

getDef

public MetadataDef<BuiltInMetadata.UniqueKeys> getDef()

Specified by:

getDef in interface MetadataHandler<BuiltInMetadata.UniqueKeys>

getUniqueKeys

public @Nullable Set<ImmutableBitSet> getUniqueKeys(Filter rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public @Nullable Set<ImmutableBitSet> getUniqueKeys(Sort rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public @Nullable Set<ImmutableBitSet> getUniqueKeys(Correlate rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public @Nullable Set<ImmutableBitSet> getUniqueKeys(TableModify rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public Set<ImmutableBitSet> getUniqueKeys(Project rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public @Nullable Set<ImmutableBitSet> getUniqueKeys(Calc rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public @Nullable Set<ImmutableBitSet> getUniqueKeys(Join rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public Set<ImmutableBitSet> getUniqueKeys(Aggregate rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public Set<ImmutableBitSet> getUniqueKeys(Union rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public Set<ImmutableBitSet> getUniqueKeys(Intersect rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

Any unique key of any input of Intersect is an unique key of the Intersect.

getUniqueKeys

public Set<ImmutableBitSet> getUniqueKeys(Minus rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

The unique keys of Minus are precisely the unique keys of its first input.

getUniqueKeys

public @Nullable Set<ImmutableBitSet> getUniqueKeys(TableScan rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public @Nullable Set<ImmutableBitSet> getUniqueKeys(Values rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)

getUniqueKeys

public @Nullable Set<ImmutableBitSet> getUniqueKeys(RelNode rel,
 RelMetadataQuery mq,
 boolean ignoreNulls)