Class GenericScanQualifier

  • All Implemented Interfaces:
    ScanQualifier, Qualifier

    public class GenericScanQualifier
    extends java.lang.Object
    implements ScanQualifier
    This is the implementation for ScanQualifier. It is used for system and user scans.
    Version:
    0.1
    • Field Detail

      • columnId

        private int columnId
      • operator

        private int operator
      • negateCR

        private boolean negateCR
      • orderedNulls

        private boolean orderedNulls
      • unknownRV

        private boolean unknownRV
      • properInit

        private boolean properInit
    • Constructor Detail

      • GenericScanQualifier

        public GenericScanQualifier()
    • Method Detail

      • getColumnId

        public int getColumnId()
        Description copied from interface: Qualifier
        Get the (zero based) id of the column to be qualified.

        This id is the column number of the column in the table, no matter whether a partial column set is being retrieved by the actual fetch. Note that the column being specified in the qualifier must appear in the column list being fetched.

        Specified by:
        getColumnId in interface Qualifier
        See Also:
        Qualifier.getColumnId()
      • clearOrderableCache

        public void clearOrderableCache()
        Clear the DataValueDescriptor cache, if one exists. (The DataValueDescriptor can be 1 of 3 types: o VARIANT - cannot be cached as its value can vary within a scan o SCAN_INVARIANT - can be cached within a scan as its value will not change within a scan o QUERY_INVARIANT- can be cached across the life of the query as its value will never change o CONSTANT - immutable
        Specified by:
        clearOrderableCache in interface Qualifier
        See Also:
        Qualifier.getUnknownRV()
      • reinitialize

        public void reinitialize()
        This method reinitializes all the state of the Qualifier. It is used to distinguish between resetting something that is query invariant and something that is constant over every execution of a query. Basically, clearOrderableCache() will only clear out its cache if it is a VARIANT or SCAN_INVARIANT value. However, each time a query is executed, the QUERY_INVARIANT qualifiers need to be reset.
        Specified by:
        reinitialize in interface Qualifier