net.sf.farrago.namespace.ftrs
Class FtrsIndexScanRel

java.lang.Object
  org.eigenbase.rel.AbstractRelNode
      org.eigenbase.rel.TableAccessRelBase
          net.sf.farrago.namespace.ftrs.FtrsIndexScanRel

All Implemented Interfaces:

Cloneable, FennelRel, RelNode

 class FtrsIndexScanRel
extends TableAccessRelBase
implements FennelRel

FtrsIndexScanRel is the relational expression corresponding to a scan via a particular index over the contents of a table stored in FTRS format.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/namespace/ftrs/FtrsIndexScanRel.java#31 $

Author:

John V. Sichi

Field Summary

(package private) FtrsTable	ftrsTable Refinement for super.table.
(package private) FemLocalIndex	index Index to use for access.
private FtrsIndexGuide	indexGuide
(package private) boolean	isOrderPreserving
(package private) Integer[]	projectedColumns Array of 0-based flattened column ordinals to project; if null, project all columns.

Fields inherited from class org.eigenbase.rel.TableAccessRelBase

connection, table

Fields inherited from class org.eigenbase.rel.AbstractRelNode

digest, id, rowType, traits

Fields inherited from interface net.sf.farrago.query.FennelRel

FENNEL_EXEC_CONVENTION

Fields inherited from interface org.eigenbase.rel.RelNode

emptyArray

Constructor Summary

FtrsIndexScanRel(RelOptCluster cluster, FtrsTable ftrsTable, FemLocalIndex index, RelOptConnection connection, Integer[] projectedColumns, boolean isOrderPreserving)
Creates a new FtrsIndexScanRel object.

Method Summary

FtrsIndexScanRel	clone() Clones this RelNode.
(package private) RelOptCost	computeCost(RelOptPlanner planner, double dRows)
private Integer[]	computeProjectedColumns()
RelOptCost	computeSelfCost(RelOptPlanner planner) Returns the cost of this plan (not including children).
(package private) void	defineScanStream(FemIndexScanDef scanStream) Fills in a stream definition for this scan.
RelDataType	deriveRowType()
void	explain(RelOptPlanWriter pw)
RelFieldCollation[]	getCollations() TODO: jhyde, 2006/3/28: unify with RelNode.getCollationList()
FemAbstractColumn	getColumnForFieldAccess(int fieldOrdinal) Gets the column referenced by a FieldAccess relative to this scan.
FtrsIndexGuide	getIndexGuide()
Object	implementFennelChild(FennelRelImplementor implementor) Visits this relational expression as part of the implementation process.
FemExecutionStreamDef	toStreamDef(FennelRelImplementor implementor) Converts this relational expression to FemExecutionStreamDef form.

Methods inherited from class org.eigenbase.rel.TableAccessRelBase

getCollationList, getConnection, getRows, getTable

Methods inherited from class org.eigenbase.rel.AbstractRelNode

childrenAccept, cloneTraits, collectVariablesSet, collectVariablesUsed, computeDigest, getChildExps, getCluster, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getInputs, getOrCreateCorrelVariable, getQuery, getRelTypeName, getRowType, getTraits, getVariablesStopped, inheritTraitsFrom, isAccessTo, isDistinct, isValid, onRegister, recomputeDigest, register, registerCorrelVariable, replaceInput, setCorrelVariable, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eigenbase.rel.RelNode

childrenAccept, collectVariablesSet, collectVariablesUsed, getChildExps, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getInputs, getOrCreateCorrelVariable, getQuery, getRelTypeName, getRows, getRowType, getTable, getTraits, getVariablesStopped, isAccessTo, isDistinct, isValid, onRegister, recomputeDigest, registerCorrelVariable, replaceInput, setCorrelVariable

Field Detail

index

final FemLocalIndex index

Index to use for access.

ftrsTable

final FtrsTable ftrsTable

Refinement for super.table.

projectedColumns

final Integer[] projectedColumns

Array of 0-based flattened column ordinals to project; if null, project all columns. Note that these ordinals are relative to the table, not the index.

isOrderPreserving

final boolean isOrderPreserving

indexGuide

private FtrsIndexGuide indexGuide

Constructor Detail

FtrsIndexScanRel

public FtrsIndexScanRel(RelOptCluster cluster,
                        FtrsTable ftrsTable,
                        FemLocalIndex index,
                        RelOptConnection connection,
                        Integer[] projectedColumns,
                        boolean isOrderPreserving)

Creates a new FtrsIndexScanRel object.

Parameters:

cluster - RelOptCluster for this rel

ftrsTable - table being scanned

index - index to use for table access

connection - connection

projectedColumns - array of 0-based table-relative column ordinals, or null to project all columns

isOrderPreserving - if true, returned rows must be in index order; if false, rows can be returned out of order

Method Detail

getIndexGuide

public FtrsIndexGuide getIndexGuide()

getColumnForFieldAccess

public FemAbstractColumn getColumnForFieldAccess(int fieldOrdinal)

Gets the column referenced by a FieldAccess relative to this scan.

Parameters:

fieldOrdinal - 0-based ordinal of an output field of the scan

Returns:

underlying column

clone

public FtrsIndexScanRel clone()

Description copied from interface: RelNode

Clones this RelNode.

Traits of the RelNode must be explicitly cloned, using AbstractRelNode.inheritTraitsFrom(AbstractRelNode), as the RelNode may have traits of which it has no knowledge. Example implementation:

     public MyRelNode clone()
     {
         MyRelNode clone = new MyRelNode(...);
         clone.inheritTraitsFrom(this);
         return clone;
     }
 

N.B.: This method must be overridden whenever an existing, concrete RelNode is extended. Otherwise, calling clone() will produce a differently typed RelNode, resulting in invalid or incorrect query plans.

Specified by:

clone in interface RelNode

Overrides:

clone in class TableAccessRelBase

Returns:

a clone of this RelNode

computeSelfCost

public RelOptCost computeSelfCost(RelOptPlanner planner)

Description copied from interface: RelNode

Returns the cost of this plan (not including children). The base implementation throws an error; derived classes should override.

NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use RelMetadataQuery.getNonCumulativeCost(org.eigenbase.rel.RelNode), which gives plugins a chance to override the rel's default ideas about cost.

Specified by:

computeSelfCost in interface RelNode

Overrides:

computeSelfCost in class TableAccessRelBase

deriveRowType

public RelDataType deriveRowType()

Overrides:

deriveRowType in class TableAccessRelBase

explain

public void explain(RelOptPlanWriter pw)

Specified by:

explain in interface RelNode

Overrides:

explain in class TableAccessRelBase

implementFennelChild

public Object implementFennelChild(FennelRelImplementor implementor)

Description copied from interface: FennelRel

Visits this relational expression as part of the implementation process. Fennel relational expressions are implemented in a two-phase process: first call this method, then call FennelRel.toStreamDef(net.sf.farrago.query.FennelRelImplementor).

Specified by:

implementFennelChild in interface FennelRel

toStreamDef

public FemExecutionStreamDef toStreamDef(FennelRelImplementor implementor)

Description copied from interface: FennelRel

Converts this relational expression to FemExecutionStreamDef form. In the process, the relational expression will almost certainly call FennelRelImplementor.visitFennelChild(net.sf.farrago.query.FennelRel, int) on each of its children.

Specified by:

toStreamDef in interface FennelRel

Parameters:

implementor - for generating Java code

Returns:

generated FemExecutionStreamDef

computeCost

RelOptCost computeCost(RelOptPlanner planner,
                       double dRows)

defineScanStream

void defineScanStream(FemIndexScanDef scanStream)

Fills in a stream definition for this scan.

Parameters:

scanStream - stream definition to fill in

computeProjectedColumns

private Integer[] computeProjectedColumns()

getCollations

public RelFieldCollation[] getCollations()

Description copied from interface: FennelRel

TODO: jhyde, 2006/3/28: unify with RelNode.getCollationList()

Specified by:

getCollations in interface FennelRel

Returns:

the sort order produced by this FennelRel, or an empty array if the output is not guaranteed to be in any particular order.