org.apache.drill.exec.physical.base

Class AbstractGroupScan

java.lang.Object

org.apache.drill.exec.physical.base.AbstractBase

org.apache.drill.exec.physical.base.AbstractGroupScan

All Implemented Interfaces:

Iterable<PhysicalOperator>, GraphValue<PhysicalOperator>, FragmentLeaf, GroupScan, HasAffinity, Leaf, PhysicalOperator, Scan

Direct Known Subclasses:

AbstractFileGroupScan, DirectGroupScan, InfoSchemaGroupScan, MockGroupScanPOP, SystemTableScan

public abstract class AbstractGroupScan
extends AbstractBase
implements GroupScan

Field Summary

Fields inherited from class org.apache.drill.exec.physical.base.AbstractBase

INIT_ALLOCATION, initialAllocation, MAX_ALLOCATION, maxAllocation

Fields inherited from interface org.apache.drill.exec.physical.base.GroupScan

ALL_COLUMNS, NO_COLUMN_STATS

Fields inherited from interface org.apache.drill.common.graph.GraphValue

logger

Constructor Summary

Constructors

Constructor and Description
AbstractGroupScan(AbstractGroupScan that)
AbstractGroupScan(String userName)

Method Summary

Methods

Modifier and Type	Method and Description
<T,X,E extends Throwable> T	accept(PhysicalVisitor<T,X,E> physicalVisitor, X value) Provides capability to build a set of output based on traversing a query graph tree.
GroupScan	applyLimit(long maxRecords) By default, return null to indicate rowcount based prune is not supported.
boolean	canPushdownProjects(List<SchemaPath> columns) GroupScan should check the list of columns, and see if it could support all the columns in the list.
GroupScan	clone(List<SchemaPath> columns) Returns a clone of GroupScan instance, except that the new GroupScan will use the provided list of columns .
boolean	enforceWidth() Deprecated.
long	getColumnValueCount(SchemaPath column) By default, throw exception, since group scan does not have exact column value count.
DistributionAffinity	getDistributionAffinity() Get distribution affinity which describes the parallelization strategy of the operator.
Collection<String>	getFiles() Returns a collection of file names associated with this GroupScan.
long	getInitialAllocation()
long	getMaxAllocation()
int	getMinParallelizationWidth() At minimum, the GroupScan requires these many fragments to run.
List<EndpointAffinity>	getOperatorAffinity() Get the list of Endpoints with associated affinities that this operator has preference for.
int	getOperatorType()
List<SchemaPath>	getPartitionColumns() Returns a list of columns that can be used for partition pruning
ScanStats	getScanStats()
ScanStats	getScanStats(PlannerSettings settings)
boolean	hasFiles() Return true if this GroupScan can return its selection as a list of file names (retrieved by getFiles()).
boolean	isExecutable() Describes whether or not a particular physical operator can actually be executed.
Iterator<PhysicalOperator>	iterator()
boolean	supportsLimitPushdown() Default is not to support limit pushdown.
boolean	supportsPartitionFilterPushdown() Whether or not this GroupScan supports pushdown of partition filters (directories for filesystems)

Methods inherited from class org.apache.drill.exec.physical.base.AbstractBase

accept, getCost, getOperatorId, getSVMode, getUserName, isBufferedOperator, setCost, setMaxAllocation, setOperatorId

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.drill.exec.physical.base.GroupScan

applyAssignments, getDigest, getMaxParallelizationWidth, getSpecificScan

Methods inherited from interface org.apache.drill.exec.physical.base.PhysicalOperator

getCost, getNewWithChildren, getOperatorId, getSVMode, getUserName, isBufferedOperator, setCost, setMaxAllocation, setOperatorId

Methods inherited from interface org.apache.drill.common.graph.GraphValue

accept

Constructor Detail

AbstractGroupScan

public AbstractGroupScan(String userName)

AbstractGroupScan

public AbstractGroupScan(AbstractGroupScan that)

Method Detail

iterator

public Iterator<PhysicalOperator> iterator()

Specified by:

iterator in interface Iterable<PhysicalOperator>

getOperatorAffinity

public List<EndpointAffinity> getOperatorAffinity()

Description copied from interface: HasAffinity

Get the list of Endpoints with associated affinities that this operator has preference for.

Specified by:

getOperatorAffinity in interface HasAffinity

Returns:

List of EndpointAffinity objects.

isExecutable

public boolean isExecutable()

Description copied from interface: PhysicalOperator

Describes whether or not a particular physical operator can actually be executed. Most physical operators can be executed. However, Exchange nodes cannot be executed. In order to be executed, they must be converted into their Exec sub components.

Specified by:

isExecutable in interface PhysicalOperator

Overrides:

isExecutable in class AbstractBase

Returns:

accept

public <T,X,E extends Throwable> T accept(PhysicalVisitor<T,X,E> physicalVisitor,
                                 X value)
         throws E extends Throwable

Description copied from interface: PhysicalOperator

Provides capability to build a set of output based on traversing a query graph tree.

Specified by:

accept in interface PhysicalOperator

Returns:

Throws:

E extends Throwable

clone

public GroupScan clone(List<SchemaPath> columns)

Description copied from interface: GroupScan

Returns a clone of GroupScan instance, except that the new GroupScan will use the provided list of columns .

Specified by:

clone in interface GroupScan

getMinParallelizationWidth

public int getMinParallelizationWidth()

Description copied from interface: GroupScan

At minimum, the GroupScan requires these many fragments to run. Currently, this is used in SimpleParallelizer

Specified by:

getMinParallelizationWidth in interface GroupScan

Returns:

the minimum number of fragments that should run

getScanStats

public ScanStats getScanStats(PlannerSettings settings)

Specified by:

getScanStats in interface GroupScan

getScanStats

public ScanStats getScanStats()

enforceWidth

@Deprecated
public boolean enforceWidth()

Deprecated.

Description copied from interface: GroupScan

Check if GroupScan enforces width to be maximum parallelization width. Currently, this is used in ExcessiveExchangeIdentifier

Specified by:

enforceWidth in interface GroupScan

Returns:

if maximum width should be enforced

getInitialAllocation

public long getInitialAllocation()

Specified by:

getInitialAllocation in interface PhysicalOperator

Overrides:

getInitialAllocation in class AbstractBase

Returns:

The memory to preallocate for this operator

getMaxAllocation

public long getMaxAllocation()

Specified by:

getMaxAllocation in interface PhysicalOperator

Overrides:

getMaxAllocation in class AbstractBase

Returns:

The maximum memory this operator can allocate

canPushdownProjects

public boolean canPushdownProjects(List<SchemaPath> columns)

Description copied from interface: GroupScan

GroupScan should check the list of columns, and see if it could support all the columns in the list.

Specified by:

canPushdownProjects in interface GroupScan

supportsPartitionFilterPushdown

public boolean supportsPartitionFilterPushdown()

Description copied from interface: GroupScan

Whether or not this GroupScan supports pushdown of partition filters (directories for filesystems)

Specified by:

supportsPartitionFilterPushdown in interface GroupScan

getColumnValueCount

public long getColumnValueCount(SchemaPath column)

By default, throw exception, since group scan does not have exact column value count.

Specified by:

getColumnValueCount in interface GroupScan

getOperatorType

public int getOperatorType()

Specified by:

getOperatorType in interface PhysicalOperator

getPartitionColumns

public List<SchemaPath> getPartitionColumns()

Description copied from interface: GroupScan

Returns a list of columns that can be used for partition pruning

Specified by:

getPartitionColumns in interface GroupScan

supportsLimitPushdown

public boolean supportsLimitPushdown()

Default is not to support limit pushdown.

Specified by:

supportsLimitPushdown in interface GroupScan

Returns:

applyLimit

public GroupScan applyLimit(long maxRecords)

By default, return null to indicate rowcount based prune is not supported. Each groupscan subclass should override, if it supports rowcount based prune.

Specified by:

applyLimit in interface GroupScan

Parameters:

maxRecords - : the number of rows requested from group scan.

Returns:

a new instance of group scan if the prune is successful. null when either if row-based prune is not supported, or if prune is not successful.

hasFiles

public boolean hasFiles()

Description copied from interface: GroupScan

Return true if this GroupScan can return its selection as a list of file names (retrieved by getFiles()).

Specified by:

hasFiles in interface GroupScan

getFiles

public Collection<String> getFiles()

Description copied from interface: GroupScan

Returns a collection of file names associated with this GroupScan. This should be called after checking hasFiles(). If this GroupScan cannot provide file names, it returns null.

Specified by:

getFiles in interface GroupScan

getDistributionAffinity

public DistributionAffinity getDistributionAffinity()

Description copied from interface: HasAffinity

Get distribution affinity which describes the parallelization strategy of the operator.

Specified by:

getDistributionAffinity in interface HasAffinity