Class 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 Detail

      • row_length

        private int row_length
        Fields of the class
      • qualifier_list

        private Qualifier[][] qualifier_list
      • materialized_cols

        private int[] materialized_cols
      • maxFetchColumnId

        private int maxFetchColumnId
      • 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.
      • 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.
      • 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.