Package org.apache.calcite.adapter.clone

Enum ArrayTable.RepresentationType

    • Enum Constant Detail

      • OBJECT_ARRAY

        public static final ArrayTable.RepresentationType OBJECT_ARRAY
        Object array. Null values are represented by null. Values may or may not be canonized; if canonized, = and != can be implemented using pointer.
        See Also:
        ArrayTable.ObjectArray

      • BIT_SLICED_PRIMITIVE_ARRAY

        public static final ArrayTable.RepresentationType BIT_SLICED_PRIMITIVE_ARRAY
        Bit-sliced primitive array. Values are bitCount bits each, and interpreted as signed. Stored as an array of long values.

        If gcd(bitCount, 64) != 0, some values will cross boundaries. bits each. But for all of those values except 4, there is a primitive type (8 byte, 16 short, 32 int) which is more efficient.

        See Also:
        ArrayTable.BitSlicedPrimitiveArray

      • PRIMITIVE_DICTIONARY

        public static final ArrayTable.RepresentationType PRIMITIVE_DICTIONARY
        Dictionary of primitives. Use one of the previous methods to store unsigned offsets into the dictionary. Dictionary is canonized and sorted, so v1 < v2 if and only if code(v1) < code(v2). The dictionary may or may not contain a null value.

        The dictionary is not beneficial unless the codes are significantly shorter than the values. A column of long values with many duplicates is a win; a column of mostly distinct short values is likely a loss. The other win is if there are null values; otherwise the best option would be an OBJECT_ARRAY.

        See Also:
        ArrayTable.PrimitiveDictionary

      • STRING_DICTIONARY

        public static final ArrayTable.RepresentationType STRING_DICTIONARY
        Compressed string table. Block of char data. Strings represented using an unsigned offset into the table (stored using one of the previous methods).

        First 2 bytes are unsigned length; subsequent bytes are string contents. The null value, strings longer than 64k and strings that occur very commonly are held in an 'exceptions' array and are recognized by their high offsets. Other strings are created on demand (this reduces the number of objects that need to be created during deserialization from cache.

        See Also:
        ArrayTable.StringDictionary

    • Constructor Detail

      • RepresentationType

        private RepresentationType()

    • Method Detail

      • values

        public static ArrayTable.RepresentationType[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows: 
        for (ArrayTable.RepresentationType c : ArrayTable.RepresentationType.values())
    System.out.println(c);
        Returns:
        an array containing the constants of this enum type, in the order they are declared

      • valueOf

        public static ArrayTable.RepresentationType valueOf​(java.lang.String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        Parameters:
        name - the name of the enum constant to be returned.
        Returns:
        the enum constant with the specified name
        Throws:
        java.lang.IllegalArgumentException - if this enum type has no constant with the specified name
        java.lang.NullPointerException - if the argument is null