org.apache.derby.impl.sql.execute
Class IndexRow

java.lang.Object
  org.apache.derby.impl.sql.execute.ValueRow
      org.apache.derby.impl.sql.execute.IndexRow

All Implemented Interfaces:

ExecIndexRow, ExecRow, java.io.Externalizable, Formatable, Row, java.io.Serializable, TypedFormat

public class IndexRow

extends ValueRow

implements ExecIndexRow

Basic implementation of ExecIndexRow.

Author:

jeff

See Also:

Serialized Form

Field Summary

private boolean[]

orderedNulls This class implements Formatable.

Fields inherited from class org.apache.derby.impl.sql.execute.ValueRow

Constructor Summary

IndexRow()
Public niladic constructor.

IndexRow(int ncols)

Method Summary

boolean	areNullsOrdered(int columnPosition) Return true if orderedNulls was called on this ExecIndexRow for the given column position.
(package private) ExecRow	cloneMe()
void	execRowToExecIndexRow(ExecRow valueRow) Turn the ExecRow into an ExecIndexRow.
int	getTypeFormatId() Get the formatID which corresponds to this class.
void	orderedNulls(int columnPosition) These two methods are a sort of a hack.
void	readExternal(java.io.ObjectInput in) Read this object from a stream of stored objects.
void	writeExternal(java.io.ObjectOutput out) Write this object to a stream of stored objects.

Methods inherited from class org.apache.derby.impl.sql.execute.ValueRow

cloneColumn, getClone, getClone, getColumn, getNewNullRow, getNewObjectArray, getRowArray, getRowArrayClone, nColumns, realloc, setColumn, setRowArray, setRowArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.derby.iapi.sql.execute.ExecRow

cloneColumn, getClone, getClone, getNewNullRow, getNewObjectArray, getRowArray, getRowArrayClone, setRowArray, setRowArray

Methods inherited from interface org.apache.derby.iapi.sql.Row

getColumn, nColumns, setColumn

Field Detail

orderedNulls

private boolean[] orderedNulls

This class implements Formatable. That means that it can write itself to and from a formatted stream. If you add more fields to this class, make sure that you also write/read them with the writeExternal()/readExternal() methods. If, inbetween releases, you add more fields to this class, then you should bump the version number emitted by the getTypeFormatId() method.

Constructor Detail

IndexRow

public IndexRow()

Public niladic constructor. Needed for Formatable interface to work.

IndexRow

public IndexRow(int ncols)

Method Detail

orderedNulls

public void orderedNulls(int columnPosition)

Description copied from interface: ExecIndexRow

These two methods are a sort of a hack. The store implements ordered null semantics for start and stop positioning, which is correct for IS NULL and incorrect for everything else. To work around this, TableScanResultSet will check whether the start and stop positions have NULL in any column position other than for an IS NULL check. If so, it won't do the scan (that is, it will return no rows). This method is to inform this ExecIndexRow (which can be used for start and stop positioning) that the given column uses ordered null semantics.

Specified by:

orderedNulls in interface ExecIndexRow

Parameters:

columnPosition - The position of the column that uses ordered null semantics (zero-based).

areNullsOrdered

public boolean areNullsOrdered(int columnPosition)

Description copied from interface: ExecIndexRow

Return true if orderedNulls was called on this ExecIndexRow for the given column position.

Specified by:

areNullsOrdered in interface ExecIndexRow

Parameters:

columnPosition - The position of the column (zero-based) for which we want to check if ordered null semantics are used.

Returns:

true if we are to use ordered null semantics on the given column

execRowToExecIndexRow

public void execRowToExecIndexRow(ExecRow valueRow)

Turn the ExecRow into an ExecIndexRow.

Specified by:

execRowToExecIndexRow in interface ExecIndexRow

Returns:

Nothing.

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Read this object from a stream of stored objects.

Specified by:

readExternal in interface java.io.Externalizable

Overrides:

readExternal in class ValueRow

Parameters:

in - read this.

Throws:

java.io.IOException - thrown on error

java.lang.ClassNotFoundException - thrown on error

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Write this object to a stream of stored objects.

Specified by:

writeExternal in interface java.io.Externalizable

Overrides:

writeExternal in class ValueRow

Parameters:

out - write bytes here.

Throws:

java.io.IOException - thrown on error

getTypeFormatId

public int getTypeFormatId()

Get the formatID which corresponds to this class.

Specified by:

getTypeFormatId in interface TypedFormat

Overrides:

getTypeFormatId in class ValueRow

Returns:

the formatID of this class

cloneMe

ExecRow cloneMe()

Overrides:

cloneMe in class ValueRow