Package com.denodo.common.custom.annotations

Annotation Interface CustomExecutor

@Target(METHOD) @Retention(RUNTIME) @Documented public @interface CustomExecutor

The method marked with this annotation will be executed when invoking this Custom Function or Custom Policy.

Custom functions that can be delegated to a database

A custom function that can be delegated to a database is a custom function that when used, the Virtual DataPort Server may invoke a function of the database, instead of executing the Java code of the custom function.

See more about this in the section Developing Custom Functions that Can Be Delegated to a Database of the Virtual DataPort Developer Guide.

To develop a Custom Function that can be delegated to a database, add the parameters implementation and delegationPatterns

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    DelegationPattern[]
    delegationPatterns
    Array of DelegationPattern objects that indicate to what databases a custom function can be delegated and what function of the database the Server has to execute.
    boolean
    implementation
    It indicates if the code of the function can be executed.
    String
    syntax
    Syntax of the Custom Element.

  • Element Details

    • syntax

      String syntax
      Syntax of the Custom Element.

      The Administration Tool uses this value to display the syntax of this element to the users.

      The default value is an empty String

      Returns:
      syntax of the Custom Element
      Default:
      ""

    • implementation

      boolean implementation
      It indicates if the code of the function can be executed.

      If true, it indicates that the code of the function also can return the proper result. The Server will execute this code when the function cannot be delegated to the database.

      If false, it indicates that the code of the custom function is not valid and the Server will never execute it. Therefore, the Server will return an error if it cannot delegate the function to the database.

      Use only when the class represents a scalar function ( CustomElementType.VDPFUNCTION) or an aggregation function ( CustomElementType.VDPAGGREGATEFUNCTION)

      Returns:
      true if the code of the function can be executed.
      Default:
      true

    • delegationPatterns

      DelegationPattern[] delegationPatterns

      Array of DelegationPattern objects that indicate to what databases a custom function can be delegated and what function of the database the Server has to execute.

      Use only when the class represents a scalar function (CustomElementType.VDPFUNCTION) or an aggregation function (CustomElementType.VDPAGGREGATEFUNCTION)

      Returns:
      Array of DelegationPattern objects
      Default:
      {}