Package se.kuseman.payloadbuilder.api.catalog

Class DatasourceData

java.lang.Object

se.kuseman.payloadbuilder.api.catalog.DatasourceData

public class DatasourceData
extends Object

Data used when a catalog is asked for creation of a data source

Constructor Summary

Constructors

Constructor	Description
DatasourceData(int nodeId, Optional<Schema> schema, List<IPredicate> predicates, List<? extends ISortItem> sortItems, List<String> projection, List<Option> options)

Method Summary

Modifier and Type	Method	Description
IExpression	extractEqualsPredicate(QualifiedName column)	Convenience method for extracting a equals predicate for specific column.
int	getNodeId()	Return the node id for this datasource.
List<Option>	getOptions()	Return defined options for this data source
List<IPredicate>	getPredicates()	Return predicates if any to push down to data source if supported by catalog
List<String>	getProjection()	Return the projected columns needed for this data source.
Optional<Schema>	getSchema()	Return the planned schema for this data source.
List<? extends ISortItem>	getSortItems()	Return sort items if any to push down to data soource if supported by catalog.

Methods inherited from class java.lang.Object

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

Constructor Details

DatasourceData

public DatasourceData(int nodeId,
 Optional<Schema> schema,
 List<IPredicate> predicates,
 List<? extends ISortItem> sortItems,
 List<String> projection,
 List<Option> options)

Method Details

getNodeId

public int getNodeId()

Return the node id for this datasource. The operator ID that this data source belongs to. Can be used in IStatementContext.getNodeData(Integer) to store custom data.

getSchema

public Optional<Schema> getSchema()

Return the planned schema for this data source. If the table was planned with a non asterisk schema then this schema should be used in the returned TupleVector's. Otherwise this value is Optional.empty() and the actual runtime schema should be provided in tuples.

getPredicates

public List<IPredicate> getPredicates()

Return predicates if any to push down to data source if supported by catalog

getSortItems

public List<? extends ISortItem> getSortItems()

Return sort items if any to push down to data soource if supported by catalog. NOTE! All or no sort items must be consumed

getProjection

public List<String> getProjection()

Return the projected columns needed for this data source. This is a optimization hint that can be used for catalogs that supports fetching of specific columns only like RDMBS:es. If empty then all column should be returned

getOptions

public List<Option> getOptions()

Return defined options for this data source

extractEqualsPredicate

public IExpression extractEqualsPredicate(QualifiedName column)

Convenience method for extracting a equals predicate for specific column.

   Ie.

   select *
   from table t
   where 'val' = t.col

 Calling this method with value 'col' would return in
 the literal string expression 'val'
 
 NOTE! Mutates the predicates list if column was found.