org.apache.derby.iapi.store.raw
Class FetchDescriptor

java.lang.Object
  extended by org.apache.derby.iapi.store.raw.FetchDescriptor

public final class FetchDescriptor
extends java.lang.Object

FetchDescriptor is used to package up all the arguments necessary to describe what rows and what row parts should be returned from the store back to language as part of a fetch.

The FetchDescriptor may also contain scratch space used to process the qualifiers passed in the scan. This scratch space will be used to cache information about the qualifiers, valid column list, row size so that calculations need only be done once per scan rather than every iteration.


Field Summary
private  int[] materialized_cols
           
private  int maxFetchColumnId
           
private  Qualifier[][] qualifier_list
           
private  int row_length
          Fields of the class
private  FormatableBitSet validColumns
           
private  int[] validColumnsArray
           
private static int[] zero_fill_array
           
private static int ZERO_FILL_LENGTH
           
 
Constructor Summary
FetchDescriptor()
          Constructors for This class:
FetchDescriptor(int input_row_length)
           
FetchDescriptor(int input_row_length, FormatableBitSet input_validColumns, Qualifier[][] input_qualifier_list)
           
FetchDescriptor(int input_row_length, int single_valid_column_number)
           
 
Method Summary
 int[] getMaterializedColumns()
          Internal to store.
 int getMaxFetchColumnId()
          Internal to store.
 Qualifier[][] getQualifierList()
          Return the qualifier array.
 FormatableBitSet getValidColumns()
          Return the column list bit map.
 int[] getValidColumnsArray()
           
 void reset()
          Internal to store.
private  void setMaxFetchColumnId()
           
 void setValidColumns(FormatableBitSet input_validColumns)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

row_length

private int row_length
Fields of the class


validColumns

private FormatableBitSet validColumns

qualifier_list

private Qualifier[][] qualifier_list

materialized_cols

private int[] materialized_cols

maxFetchColumnId

private int maxFetchColumnId

ZERO_FILL_LENGTH

private static final int ZERO_FILL_LENGTH
See Also:
Constant Field Values

zero_fill_array

private static final int[] zero_fill_array

validColumnsArray

private int[] validColumnsArray
Constructor Detail

FetchDescriptor

FetchDescriptor()
Constructors for This class:


FetchDescriptor

public FetchDescriptor(int input_row_length)

FetchDescriptor

public FetchDescriptor(int input_row_length,
                       int single_valid_column_number)

FetchDescriptor

public FetchDescriptor(int input_row_length,
                       FormatableBitSet input_validColumns,
                       Qualifier[][] input_qualifier_list)
Method Detail

getValidColumns

public final FormatableBitSet getValidColumns()
Return the column list bit map.

A description of which columns to return from every fetch in the scan. A row array and a valid column bit map work together to describe the row to be returned by the scan - see RowUtil for description of how these two parameters work together to describe a "row".

Returns:
The column list bit map.
Throws:
StandardException - Standard exception policy.

getValidColumnsArray

public final int[] getValidColumnsArray()

setValidColumns

public final void setValidColumns(FormatableBitSet input_validColumns)

getQualifierList

public final Qualifier[][] getQualifierList()
Return the qualifier array.

Return the array of qualifiers in this FetchDescriptor. The array of qualifiers which, applied to each key, restricts the rows returned by the scan. Rows for which any one of the qualifiers returns false are not returned by the scan. If null, all rows are returned. Qualifiers can only reference columns which are included in the scanColumnList. The column id that a qualifier returns in the column id the table, not the column id in the partial row being returned.

A null qualifier array means there are no qualifiers.

Returns:
The qualifier array, it may be null.
Throws:
StandardException - Standard exception policy.

getMaterializedColumns

public final int[] getMaterializedColumns()
Internal to store.


getMaxFetchColumnId

public final int getMaxFetchColumnId()
Internal to store.


setMaxFetchColumnId

private final void setMaxFetchColumnId()

reset

public final void reset()
Internal to store.


Built on Thu 2011-03-10 11:54:14+0000, from revision ???

Apache Derby V10.6 Internals - Copyright © 2004,2007 The Apache Software Foundation. All Rights Reserved.