Enum IsolationLevel

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Comparable<IsolationLevel>

    public enum IsolationLevel
    extends java.lang.Enum<IsolationLevel>
    An isolation level in a table.

    Two isolation levels are supported: serializable and snapshot isolation. Both of them provide a read consistent view of the table to all operations and allow readers to see only already committed data. While serializable is the strongest isolation level in databases, snapshot isolation is beneficial for environments with many concurrent writers.

    The serializable isolation level guarantees that an ongoing UPDATE/DELETE/MERGE operation fails if a concurrent transaction commits a new file that might contain rows matching the condition used in UPDATE/DELETE/MERGE. For example, if there is an ongoing update on a subset of rows and a concurrent transaction adds a new file with records that potentially match the update condition, the update operation must fail under the serializable isolation but can still commit under the snapshot isolation.

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static IsolationLevel fromName​(java.lang.String levelName)  
      static IsolationLevel valueOf​(java.lang.String name)
      Returns the enum constant of this type with the specified name.
      static IsolationLevel[] values()
      Returns an array containing the constants of this enum type, in the order they are declared.
      • Methods inherited from class java.lang.Enum

        clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf
      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, wait, wait, wait
    • Method Detail

      • values

        public static IsolationLevel[] 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 (IsolationLevel c : IsolationLevel.values())
            System.out.println(c);
        
        Returns:
        an array containing the constants of this enum type, in the order they are declared
      • valueOf

        public static IsolationLevel 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
      • fromName

        public static IsolationLevel fromName​(java.lang.String levelName)