org.apache.calcite.rel.logical

Class LogicalTableScan

java.lang.Object

org.apache.calcite.rel.AbstractRelNode

org.apache.calcite.rel.core.TableScan

org.apache.calcite.rel.logical.LogicalTableScan

All Implemented Interfaces:

Cloneable, org.apache.calcite.plan.RelOptNode, org.apache.calcite.rel.hint.Hintable, org.apache.calcite.rel.RelNode

public final class LogicalTableScan
extends org.apache.calcite.rel.core.TableScan

A LogicalTableScan reads all the rows from a RelOptTable.

This class is copied from Calcite because the explainTerms(org.apache.calcite.rel.RelWriter) should consider hints.

If the table is a net.sf.saffron.ext.JdbcTable, then this is literally possible. But for other kinds of tables, there may be many ways to read the data from the table. For some kinds of table, it may not even be possible to read all of the rows unless some narrowing constraint is applied.

In the example of the net.sf.saffron.ext.ReflectSchema schema,

select from fields

cannot be implemented, but

select from fields as f
 where f.getClass().getName().equals("java.lang.String")

can. It is the optimizer's responsibility to find these ways, by applying transformation rules.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.calcite.rel.RelNode

org.apache.calcite.rel.RelNode.Context

Field Summary

Fields inherited from class org.apache.calcite.rel.core.TableScan

hints, table

Fields inherited from class org.apache.calcite.rel.AbstractRelNode

digest, id, rowType, traitSet

Constructor Summary

Constructors

Constructor and Description
LogicalTableScan(org.apache.calcite.rel.RelInput input) Creates a LogicalTableScan by parsing serialized output.
LogicalTableScan(org.apache.calcite.plan.RelOptCluster cluster, org.apache.calcite.plan.RelOptTable table) Deprecated.
LogicalTableScan(org.apache.calcite.plan.RelOptCluster cluster, org.apache.calcite.plan.RelTraitSet traitSet, List<org.apache.calcite.rel.hint.RelHint> hints, org.apache.calcite.plan.RelOptTable table) Creates a LogicalTableScan.
LogicalTableScan(org.apache.calcite.plan.RelOptCluster cluster, org.apache.calcite.plan.RelTraitSet traitSet, org.apache.calcite.plan.RelOptTable table) Deprecated.

Method Summary

Modifier and Type	Method and Description
org.apache.calcite.rel.RelNode	copy(org.apache.calcite.plan.RelTraitSet traitSet, List<org.apache.calcite.rel.RelNode> inputs)
static LogicalTableScan	create(org.apache.calcite.plan.RelOptCluster cluster, org.apache.calcite.plan.RelOptTable relOptTable, List<org.apache.calcite.rel.hint.RelHint> hints) Creates a LogicalTableScan.
org.apache.calcite.rel.RelWriter	explainTerms(org.apache.calcite.rel.RelWriter pw)
org.apache.calcite.rel.RelNode	withHints(List<org.apache.calcite.rel.hint.RelHint> hintList)

Methods inherited from class org.apache.calcite.rel.core.TableScan

accept, computeSelfCost, deriveRowType, estimateRowCount, getHints, getTable, identity, identity, project

Methods inherited from class org.apache.calcite.rel.AbstractRelNode

accept, childrenAccept, collectVariablesSet, collectVariablesUsed, deepEquals, deepHashCode, equals, explain, getCluster, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getInputs, getRelDigest, getRelTypeName, getRowType, getTraitSet, getVariablesSet, hashCode, isEnforcer, isValid, metadata, onRegister, recomputeDigest, register, replaceInput, sole, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.calcite.rel.hint.Hintable

attachHints

Methods inherited from interface org.apache.calcite.rel.RelNode

explain

Constructor Detail

LogicalTableScan

public LogicalTableScan(org.apache.calcite.plan.RelOptCluster cluster,
                        org.apache.calcite.plan.RelTraitSet traitSet,
                        List<org.apache.calcite.rel.hint.RelHint> hints,
                        org.apache.calcite.plan.RelOptTable table)

Creates a LogicalTableScan.

Use create(org.apache.calcite.plan.RelOptCluster, org.apache.calcite.plan.RelOptTable, java.util.List<org.apache.calcite.rel.hint.RelHint>) unless you know what you're doing.

LogicalTableScan

@Deprecated
public LogicalTableScan(org.apache.calcite.plan.RelOptCluster cluster,
                                    org.apache.calcite.plan.RelTraitSet traitSet,
                                    org.apache.calcite.plan.RelOptTable table)

Deprecated.

LogicalTableScan

@Deprecated
public LogicalTableScan(org.apache.calcite.plan.RelOptCluster cluster,
                                    org.apache.calcite.plan.RelOptTable table)

Deprecated.

LogicalTableScan

public LogicalTableScan(org.apache.calcite.rel.RelInput input)

Creates a LogicalTableScan by parsing serialized output.

Method Detail

copy

public org.apache.calcite.rel.RelNode copy(org.apache.calcite.plan.RelTraitSet traitSet,
                                           List<org.apache.calcite.rel.RelNode> inputs)

Specified by:

copy in interface org.apache.calcite.rel.RelNode

Overrides:

copy in class org.apache.calcite.rel.AbstractRelNode

explainTerms

public org.apache.calcite.rel.RelWriter explainTerms(org.apache.calcite.rel.RelWriter pw)

Overrides:

explainTerms in class org.apache.calcite.rel.core.TableScan

create

public static LogicalTableScan create(org.apache.calcite.plan.RelOptCluster cluster,
                                      org.apache.calcite.plan.RelOptTable relOptTable,
                                      List<org.apache.calcite.rel.hint.RelHint> hints)

Creates a LogicalTableScan.

Parameters:

cluster - Cluster

relOptTable - Table

hints - The hints

withHints

public org.apache.calcite.rel.RelNode withHints(List<org.apache.calcite.rel.hint.RelHint> hintList)