org.apache.iceberg

Class BaseScanTaskGroup<T extends ScanTask>

java.lang.Object

org.apache.iceberg.BaseScanTaskGroup<T>

All Implemented Interfaces:

java.io.Serializable, ScanTask, ScanTaskGroup<T>

public class BaseScanTaskGroup<T extends ScanTask>
extends java.lang.Object
implements ScanTaskGroup<T>

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
BaseScanTaskGroup(java.util.Collection<T> tasks)
BaseScanTaskGroup(StructLike groupingKey, java.util.Collection<T> tasks)

Method Summary

Modifier and Type	Method and Description
long	estimatedRowsCount() The estimated number of rows produced by this scan task.
int	filesCount() The number of files that will be opened by this scan task.
StructLike	groupingKey() Returns a grouping key for this task group.
long	sizeBytes() The number of bytes that should be read by this scan task.
java.util.Collection<T>	tasks() Returns scan tasks in this group.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.iceberg.ScanTask

asCombinedScanTask, asDataTask, asFileScanTask, isDataTask, isFileScanTask

Constructor Detail

BaseScanTaskGroup

public BaseScanTaskGroup(StructLike groupingKey,
                         java.util.Collection<T> tasks)

BaseScanTaskGroup

public BaseScanTaskGroup(java.util.Collection<T> tasks)

Method Detail

groupingKey

public StructLike groupingKey()

Description copied from interface: ScanTaskGroup

Returns a grouping key for this task group.

A grouping key is a set of values that are common amongst all rows produced by the tasks in this task group. The values may be the result of transforming the underlying data. For example, a grouping key can consist of a bucket ordinal computed by applying a bucket transform to a column of the underlying rows. The grouping key type is determined at planning time and is identical across all task groups produced by a scan.

Implementations should return an empty struct if the data grouping is random or unknown.

Specified by:

groupingKey in interface ScanTaskGroup<T extends ScanTask>

Returns:

a grouping key for this task group

tasks

public java.util.Collection<T> tasks()

Description copied from interface: ScanTaskGroup

Returns scan tasks in this group.

Specified by:

tasks in interface ScanTaskGroup<T extends ScanTask>

sizeBytes

public long sizeBytes()

Description copied from interface: ScanTask

The number of bytes that should be read by this scan task.

Specified by:

sizeBytes in interface ScanTask

Specified by:

sizeBytes in interface ScanTaskGroup<T extends ScanTask>

Returns:

the total number of bytes to read

estimatedRowsCount

public long estimatedRowsCount()

Description copied from interface: ScanTask

The estimated number of rows produced by this scan task.

Specified by:

estimatedRowsCount in interface ScanTask

Specified by:

estimatedRowsCount in interface ScanTaskGroup<T extends ScanTask>

Returns:

the estimated number of produced rows

filesCount

public int filesCount()

Description copied from interface: ScanTask

The number of files that will be opened by this scan task.

Specified by:

filesCount in interface ScanTask

Specified by:

filesCount in interface ScanTaskGroup<T extends ScanTask>

Returns:

the number of files to open

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object