Class FetchDescriptor
- java.lang.Object
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- org.apache.derby.iapi.store.raw.FetchDescriptor
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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.
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Field Summary
Fields Modifier and Type Field Description private int[]
materialized_cols
private int
maxFetchColumnId
private Qualifier[][]
qualifier_list
private int
row_length
Fields of the classprivate FormatableBitSet
validColumns
private int[]
validColumnsArray
private static int[]
zero_fill_array
private static int
ZERO_FILL_LENGTH
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Constructor Summary
Constructors Constructor Description FetchDescriptor()
Constructors for This class:FetchDescriptor(int input_row_length)
FetchDescriptor(int input_row_length, int single_valid_column_number)
FetchDescriptor(int input_row_length, FormatableBitSet input_validColumns, Qualifier[][] input_qualifier_list)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description 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)
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Field Detail
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row_length
private int row_length
Fields of the class
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validColumns
private FormatableBitSet validColumns
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qualifier_list
private Qualifier[][] qualifier_list
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materialized_cols
private int[] materialized_cols
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maxFetchColumnId
private int maxFetchColumnId
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ZERO_FILL_LENGTH
private static final int ZERO_FILL_LENGTH
- See Also:
- Constant Field Values
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zero_fill_array
private static final int[] zero_fill_array
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validColumnsArray
private int[] validColumnsArray
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Constructor Detail
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FetchDescriptor
FetchDescriptor()
Constructors for This class:
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FetchDescriptor
public FetchDescriptor(int input_row_length)
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FetchDescriptor
public FetchDescriptor(int input_row_length, int single_valid_column_number)
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FetchDescriptor
public FetchDescriptor(int input_row_length, FormatableBitSet input_validColumns, Qualifier[][] input_qualifier_list)
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Method Detail
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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.
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getValidColumnsArray
public final int[] getValidColumnsArray()
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setValidColumns
public final void setValidColumns(FormatableBitSet input_validColumns)
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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.
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getMaterializedColumns
public final int[] getMaterializedColumns()
Internal to store.
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getMaxFetchColumnId
public final int getMaxFetchColumnId()
Internal to store.
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setMaxFetchColumnId
private final void setMaxFetchColumnId()
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reset
public final void reset()
Internal to store.
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