Class ConstantActionActivation

java.lang.Object
org.apache.derby.impl.sql.execute.BaseActivation
org.apache.derby.impl.sql.execute.ConstantActionActivation
All Implemented Interfaces:
Dependable, GeneratedByteCode, Activation, Dependent, CursorActivation

public final class ConstantActionActivation extends BaseActivation
A pre-compiled activation that supports a single ResultSet with a single constant action. All the execution logic is contained in the constant action.

At compile time for DDL statements this class will be picked as the implementation of Activation. The language PreparedStatement will contain the ConstantAction created at compiled time. At execute time this class then fetches a language ResultSet using ResultSetFactory.getDDLResultSet and executing the ResultSet will invoke the execute on the ConstantAction.

  • Constructor Details

    • ConstantActionActivation

      public ConstantActionActivation()
  • Method Details

    • shouldWeCheckRowCounts

      protected boolean shouldWeCheckRowCounts()
      Always return false since constant actions don't need recompilation when the row counts change.
      Overrides:
      shouldWeCheckRowCounts in class BaseActivation
      Returns:
      true if the row counts should be checked, false otherwise
    • createResultSet

      protected ResultSet createResultSet() throws StandardException
      Description copied from class: BaseActivation
      Create the ResultSet tree for this statement.
      Specified by:
      createResultSet in class BaseActivation
      Returns:
      the root of the ResultSet tree for this statement
      Throws:
      StandardException - standard error policy
    • postConstructor

      public void postConstructor()
      Description copied from interface: GeneratedByteCode
      Called by the class manager just after calling setGC().