com.hazelcast.org.apache.calcite.plan.RelOptTable Maven / Gradle / Ivy
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* (the "License"); you may not use this file except in com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.org.licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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package com.hazelcast.org.apache.calcite.plan;
import com.hazelcast.org.apache.calcite.linq4j.tree.Expression;
import com.hazelcast.org.apache.calcite.rel.RelCollation;
import com.hazelcast.org.apache.calcite.rel.RelDistribution;
import com.hazelcast.org.apache.calcite.rel.RelNode;
import com.hazelcast.org.apache.calcite.rel.RelReferentialConstraint;
import com.hazelcast.org.apache.calcite.rel.RelRoot;
import com.hazelcast.org.apache.calcite.rel.hint.RelHint;
import com.hazelcast.org.apache.calcite.rel.metadata.RelMetadataQuery;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.rel.type.RelDataTypeField;
import com.hazelcast.org.apache.calcite.schema.ColumnStrategy;
import com.hazelcast.org.apache.calcite.schema.Wrapper;
import com.hazelcast.org.apache.calcite.util.ImmutableBitSet;
import java.util.List;
/**
* Represents a relational dataset in a {@link RelOptSchema}. It has methods to
* describe and implement itself.
*/
public interface RelOptTable extends Wrapper {
//~ Methods ----------------------------------------------------------------
/**
* Obtains an identifier for this table. The identifier must be unique with
* respect to the Connection producing this table.
*
* @return qualified name
*/
List getQualifiedName();
/**
* Returns an estimate of the number of rows in the table.
*/
double getRowCount();
/**
* Describes the type of rows returned by this table.
*/
RelDataType getRowType();
/**
* Returns the {@link RelOptSchema} this table belongs to.
*/
RelOptSchema getRelOptSchema();
/**
* Converts this table into a {@link RelNode relational expression}.
*
* The {@link com.hazelcast.org.apache.calcite.plan.RelOptPlanner planner} calls this
* method to convert a table into an initial relational expression,
* generally something abstract, such as a
* {@link com.hazelcast.org.apache.calcite.rel.logical.LogicalTableScan},
* then optimizes this expression by
* applying {@link com.hazelcast.org.apache.calcite.plan.RelOptRule rules} to transform it
* into more efficient access methods for this table.
*/
RelNode toRel(ToRelContext context);
/**
* Returns a description of the physical ordering (or orderings) of the rows
* returned from this table.
*
* @see RelMetadataQuery#collations(RelNode)
*/
List getCollationList();
/**
* Returns a description of the physical distribution of the rows
* in this table.
*
* @see RelMetadataQuery#distribution(RelNode)
*/
RelDistribution getDistribution();
/**
* Returns whether the given columns are a key or a superset of a unique key
* of this table.
*
* @param columns Ordinals of key columns
* @return Whether the given columns are a key or a superset of a key
*/
boolean isKey(ImmutableBitSet columns);
/**
* Returns a list of unique keys, empty list if no key exist,
* the result should be consistent with {@code isKey}
*/
List getKeys();
/**
* Returns the referential constraints existing for this table. These constraints
* are represented over other tables using {@link RelReferentialConstraint} nodes.
*/
List getReferentialConstraints();
/**
* Generates code for this table.
*
* @param clazz The desired collection class; for example {@code Queryable}.
*
* @return the code for the table, or null if code generation is not supported
*/
Expression getExpression(Class clazz);
/** 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.
*/
RelOptTable extend(List extendedFields);
/** Returns a list describing how each column is populated. The list has the
* same number of entries as there are fields, and is immutable. */
List getColumnStrategies();
/** Can expand a view into relational expressions. */
interface ViewExpander {
/**
* Returns a relational expression that is to be substituted for an access
* to a SQL view.
*
* @param rowType Row type of the view
* @param queryString Body of the view
* @param schemaPath Path of a schema wherein to find referenced tables
* @param viewPath Path of the view, ending with its name; may be null
* @return Relational expression
*/
RelRoot expandView(RelDataType rowType, String queryString,
List schemaPath, List viewPath);
}
/** Contains the context needed to convert a a table into a relational
* expression. */
interface ToRelContext extends ViewExpander {
RelOptCluster getCluster();
/**
* Returns the table hints of the table to convert,
* usually you can use the hints to pass along some dynamic params.
*
* @return the hints attached to the table, never null
*/
List getTableHints();
}
}