Package org.apache.druid.sql.calcite.rel

Class DruidRels

java.lang.Object

org.apache.druid.sql.calcite.rel.DruidRels

public class DruidRels
extends Object

Constructor Summary

Constructors

Constructor	Description
DruidRels()

Method Summary

Modifier and Type	Method	Description
static RowSignature	dataSourceSignature(DruidRel<?> druidRel)	Returns the signature of the datasource of a DruidRel.
static Optional<DruidTable>	druidTableIfLeafRel(DruidRel<?> druidRel)	Returns the DataSource involved in a leaf query of class DruidQueryRel.
static boolean	isScanOrMapping(DruidRel<?> druidRel, boolean canBeJoinOrUnion)	Check if a druidRel is a simple table scan, or a projection that merely remaps columns without transforming them.
static boolean	isScanOrProject(DruidRel<?> druidRel, boolean canBeJoinOrUnion)	Check if a druidRel is a simple table scan or a scan + projection.

Methods inherited from class java.lang.Object

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

Constructor Details

DruidRels

public DruidRels()

Method Details

druidTableIfLeafRel

public static Optional<DruidTable> druidTableIfLeafRel(DruidRel<?> druidRel)

Returns the DataSource involved in a leaf query of class DruidQueryRel.

isScanOrMapping

public static boolean isScanOrMapping(DruidRel<?> druidRel,
 boolean canBeJoinOrUnion)

Check if a druidRel is a simple table scan, or a projection that merely remaps columns without transforming them. Like isScanOrProject(org.apache.druid.sql.calcite.rel.DruidRel<?>, boolean) but more restrictive: only remappings are allowed.

Parameters:

druidRel - the rel to check

canBeJoinOrUnion - consider a DruidJoinQueryRel or DruidUnionDataSourceRel as possible scans-and-mappings too.

isScanOrProject

public static boolean isScanOrProject(DruidRel<?> druidRel,
 boolean canBeJoinOrUnion)

Check if a druidRel is a simple table scan or a scan + projection.

Parameters:

druidRel - the rel to check

canBeJoinOrUnion - consider a DruidJoinQueryRel or DruidUnionDataSourceRel as possible scans-and-mappings too.

dataSourceSignature

public static RowSignature dataSourceSignature(DruidRel<?> druidRel)

Returns the signature of the datasource of a DruidRel. This is not the signature of the DruidRel itself: in particular, it ignores any operations that are layered on top of the datasource.