Package com.sleepycat.db

Class JoinConfig

java.lang.Object
com.sleepycat.db.JoinConfig
All Implemented Interfaces:
Cloneable
public class JoinConfig extends Object implements Cloneable
The configuration properties of a JoinCursor. The join cursor configuration is specified when calling Database.join.

To create a configuration object with default attributes: 

    JoinConfig config = new JoinConfig();
To set custom attributes: 
    JoinConfig config = new JoinConfig();
    config.setNoSort(true);

See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final JoinConfig
    DEFAULT
    Default configuration used if null is passed to Database.join

  • Constructor Summary

    Constructors
    Constructor
    Description
    JoinConfig()
    Creates an instance with the system's default settings.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    getNoSort()
    Returns whether automatic sorting of the input cursors is disabled.
    void
    setNoSort(boolean noSort)
    Specifies whether automatic sorting of the input cursors is disabled.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

  • Constructor Details

    • JoinConfig

      public JoinConfig()
      Creates an instance with the system's default settings.

  • Method Details

    • setNoSort

      public void setNoSort(boolean noSort)
      Specifies whether automatic sorting of the input cursors is disabled.

      Joined values are retrieved by doing a sequential iteration over the first cursor in the cursor array, and a nested iteration over each following cursor in the order they are specified in the array. This requires database traversals to search for the current datum in all the cursors after the first. For this reason, the best join performance normally results from sorting the cursors from the one that refers to the least number of data items to the one that refers to the most. Unless this method is called with true, Database.join does this sort on behalf of its caller.

      If the data are structured so that cursors with many data items also share many common elements, higher performance will result from listing those cursors before cursors with fewer data items; that is, a sort order other than the default. Calling this method permits applications to perform join optimization prior to calling Database.join.

      Parameters:
      noSort - whether automatic sorting of the input cursors is disabled.

      See Also:

    • getNoSort

      public boolean getNoSort()
      Returns whether automatic sorting of the input cursors is disabled.

      Returns:
      whether automatic sorting of the input cursors is disabled.

      See Also: