org.apache.calcite.plan

Interface RelOptTable

All Superinterfaces:

Wrapper

All Known Subinterfaces:

Prepare.PreparingTable

All Known Implementing Classes:

Prepare.AbstractPreparingTable, RelOptAbstractTable, RelOptTableImpl

public interface RelOptTable
extends Wrapper

Represents a relational dataset in a RelOptSchema. It has methods to describe and implement itself.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	RelOptTable.ToRelContext Contains the context needed to convert a a table into a relational expression.
static interface	RelOptTable.ViewExpander Can expand a view into relational expressions.

Method Summary

Modifier and Type	Method and Description
RelOptTable	extend(List<RelDataTypeField> extendedFields) Returns a table with the given extra fields.
@Nullable List<RelCollation>	getCollationList() Returns a description of the physical ordering (or orderings) of the rows returned from this table.
List<ColumnStrategy>	getColumnStrategies() Returns a list describing how each column is populated.
@Nullable RelDistribution	getDistribution() Returns a description of the physical distribution of the rows in this table.
@Nullable org.apache.calcite.linq4j.tree.Expression	getExpression(Class clazz) Generates code for this table.
@Nullable List<ImmutableBitSet>	getKeys() Returns a list of unique keys, empty list if no key exist, the result should be consistent with isKey.
List<String>	getQualifiedName() Obtains an identifier for this table.
@Nullable List<RelReferentialConstraint>	getReferentialConstraints() Returns the referential constraints existing for this table.
@Nullable RelOptSchema	getRelOptSchema() Returns the RelOptSchema this table belongs to.
double	getRowCount() Returns an estimate of the number of rows in the table.
RelDataType	getRowType() Describes the type of rows returned by this table.
boolean	isKey(ImmutableBitSet columns) Returns whether the given columns are a key or a superset of a unique key of this table.
RelNode	toRel(RelOptTable.ToRelContext context) Converts this table into a relational expression.

Methods inherited from interface org.apache.calcite.schema.Wrapper

maybeUnwrap, unwrap, unwrapOrThrow

Method Detail

getQualifiedName

List<String> getQualifiedName()

Obtains an identifier for this table. The identifier must be unique with respect to the Connection producing this table.

Returns:

qualified name

getRowCount

double getRowCount()

Returns an estimate of the number of rows in the table.

getRowType

RelDataType getRowType()

Describes the type of rows returned by this table.

getRelOptSchema

@Nullable RelOptSchema getRelOptSchema()

Returns the RelOptSchema this table belongs to.

toRel

RelNode toRel(RelOptTable.ToRelContext context)

Converts this table into a relational expression.

The planner calls this method to convert a table into an initial relational expression, generally something abstract, such as a LogicalTableScan, then optimizes this expression by applying rules to transform it into more efficient access methods for this table.

getCollationList

@Nullable List<RelCollation> getCollationList()

Returns a description of the physical ordering (or orderings) of the rows returned from this table.

See Also:

RelMetadataQuery.collations(RelNode)

getDistribution

@Nullable RelDistribution getDistribution()

Returns a description of the physical distribution of the rows in this table.

See Also:

RelMetadataQuery.distribution(RelNode)

isKey

boolean isKey(ImmutableBitSet columns)

Returns whether the given columns are a key or a superset of a unique key of this table.

Parameters:

columns - Ordinals of key columns

Returns:

Whether the given columns are a key or a superset of a key

getKeys

@Nullable List<ImmutableBitSet> getKeys()

Returns a list of unique keys, empty list if no key exist, the result should be consistent with isKey.

getReferentialConstraints

@Nullable List<RelReferentialConstraint> getReferentialConstraints()

Returns the referential constraints existing for this table. These constraints are represented over other tables using RelReferentialConstraint nodes.

getExpression

@Nullable org.apache.calcite.linq4j.tree.Expression getExpression(Class clazz)

Generates code for this table.

Parameters:

clazz - The desired collection class; for example Queryable.

Returns:

the code for the table, or null if code generation is not supported

extend

RelOptTable extend(List<RelDataTypeField> extendedFields)

Returns a table with the given extra fields.

The extended table includes the fields of this base table plus the extended fields that do not have the same name as a field in the base table.

getColumnStrategies

List<ColumnStrategy> getColumnStrategies()

Returns a list describing how each column is populated. The list has the same number of entries as there are fields, and is immutable.