Package org.apache.flink.table.types.logical

Enum LogicalTypeRoot

  • All Implemented Interfaces:
    Serializable, Comparable<LogicalTypeRoot>
    @PublicEvolving
public enum LogicalTypeRoot
extends Enum<LogicalTypeRoot>
    An enumeration of logical type roots containing static information about logical data types.

    A root is an essential description of a LogicalType without additional parameters. For example, a parameterized logical type DECIMAL(12,3) possesses all characteristics of its root DECIMAL. Additionally, a logical type root enables efficient comparison during the evaluation of types.

    The enumeration is very close to the SQL standard in terms of naming and completeness. However, it reflects just a subset of the evolving standard and contains some extensions (such as NULL, SYMBOL, or RAW).

    See the type-implementing classes for a more detailed description of each type.

    Note to implementers: Whenever we perform a match against a type root (e.g. using a switch/case statement), it is recommended to:

    • Order the items by the type root definition in this class for easy readability.
    • Think about the behavior of all type roots for the implementation. A default fallback is dangerous when introducing a new type root in the future.
    • In many runtime cases, resolve the indirection of DISTINCT_TYPE: return myMethod(((DistinctType) type).getSourceType)