org.apache.drill.exec.planner.logical

Class DrillPushProjectIntoScanRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.drill.exec.planner.logical.DrillPushProjectIntoScanRule

public class DrillPushProjectIntoScanRule
extends org.apache.calcite.plan.RelOptRule

When table support project push down, rule can be applied to reduce number of read columns thus improving scan operator performance.

Field Summary

Fields

Modifier and Type	Field and Description
static org.apache.calcite.plan.RelOptRule	DRILL_LOGICAL_INSTANCE
static org.apache.calcite.plan.RelOptRule	DRILL_PHYSICAL_INSTANCE
static org.apache.calcite.plan.RelOptRule	INSTANCE

Fields inherited from class org.apache.calcite.plan.RelOptRule

description, operands, relBuilderFactory

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DrillPushProjectIntoScanRule(Class<? extends org.apache.calcite.rel.core.Project> projectClass, Class<? extends org.apache.calcite.rel.core.TableScan> scanClass, String description)

Method Summary

Modifier and Type	Method and Description
protected boolean	canPushProjectIntoScan(org.apache.calcite.plan.RelOptTable table, DrillRelOptUtil.ProjectPushInfo projectPushInfo) Push project into scan be done only if this is not a star query and table supports project push down.
protected org.apache.calcite.rel.core.Project	createProject(org.apache.calcite.rel.core.Project project, org.apache.calcite.rel.core.TableScan newScan, List<org.apache.calcite.rex.RexNode> newProjects) Creates new DrillProjectRelBase instance with specified TableScan newScan child and List<RexNode> newProjects expressions using specified Project project as prototype.
protected org.apache.calcite.rel.core.TableScan	createScan(org.apache.calcite.rel.core.TableScan scan, DrillRelOptUtil.ProjectPushInfo projectPushInfo) Creates new DrillScanRelBase instance with row type and fields list obtained from specified ProjectPushInfo projectPushInfo using specified TableScan scan as prototype.
void	onMatch(org.apache.calcite.plan.RelOptRuleCall call)
protected boolean	skipScanConversion(org.apache.calcite.rel.type.RelDataType projectRelDataType, org.apache.calcite.rel.core.TableScan scan) Checks whether conversion of input TableScan instance to target TableScan may be omitted.

Methods inherited from class org.apache.calcite.plan.RelOptRule

any, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final org.apache.calcite.plan.RelOptRule INSTANCE

DRILL_LOGICAL_INSTANCE

public static final org.apache.calcite.plan.RelOptRule DRILL_LOGICAL_INSTANCE

DRILL_PHYSICAL_INSTANCE

public static final org.apache.calcite.plan.RelOptRule DRILL_PHYSICAL_INSTANCE

Constructor Detail

DrillPushProjectIntoScanRule

protected DrillPushProjectIntoScanRule(Class<? extends org.apache.calcite.rel.core.Project> projectClass,
                                       Class<? extends org.apache.calcite.rel.core.TableScan> scanClass,
                                       String description)

Method Detail

onMatch

public void onMatch(org.apache.calcite.plan.RelOptRuleCall call)

Specified by:

onMatch in class org.apache.calcite.plan.RelOptRule

skipScanConversion

protected boolean skipScanConversion(org.apache.calcite.rel.type.RelDataType projectRelDataType,
                                     org.apache.calcite.rel.core.TableScan scan)

Checks whether conversion of input TableScan instance to target TableScan may be omitted.

Parameters:

projectRelDataType - project rel data type

scan - TableScan to be checked

Returns:

true if specified TableScan has the same row type as specified.

createProject

protected org.apache.calcite.rel.core.Project createProject(org.apache.calcite.rel.core.Project project,
                                                            org.apache.calcite.rel.core.TableScan newScan,
                                                            List<org.apache.calcite.rex.RexNode> newProjects)

Creates new DrillProjectRelBase instance with specified TableScan newScan child and List<RexNode> newProjects expressions using specified Project project as prototype.

Parameters:

project - the prototype of resulting project

newScan - new project child

newProjects - new project expressions

Returns:

new project instance

createScan

protected org.apache.calcite.rel.core.TableScan createScan(org.apache.calcite.rel.core.TableScan scan,
                                                           DrillRelOptUtil.ProjectPushInfo projectPushInfo)

Creates new DrillScanRelBase instance with row type and fields list obtained from specified ProjectPushInfo projectPushInfo using specified TableScan scan as prototype.

Parameters:

scan - the prototype of resulting scan

projectPushInfo - the source of row type and fields list

Returns:

new scan instance

canPushProjectIntoScan

protected boolean canPushProjectIntoScan(org.apache.calcite.plan.RelOptTable table,
                                         DrillRelOptUtil.ProjectPushInfo projectPushInfo)
                                  throws IOException

Push project into scan be done only if this is not a star query and table supports project push down.

Parameters:

table - table instance

projectPushInfo - fields information

Returns:

true if push project into scan can be performed, false otherwise

Throws:

IOException