com.sleepycat.client

Class SJoinConfig

java.lang.Object

com.sleepycat.client.SJoinConfig

public class SJoinConfig
extends java.lang.Object

The configuration properties of a SJoinCursor. The join cursor configuration is specified when calling SDatabase.join(com.sleepycat.client.SCursor[], com.sleepycat.client.SJoinConfig).

To create a configuration object with default attributes:

  SJoinConfig config = new SJoinConfig();
 

To set custom attributes:

  SJoinConfig config = new SJoinConfig();
  config.setNoSort(true);
 

Constructor Summary

Constructors

Constructor and Description
SJoinConfig() Creates an instance with the default settings.

Method Summary

Modifier and Type	Method and 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

Constructor Detail

SJoinConfig

public SJoinConfig()

Creates an instance with the default settings.

Method Detail

getNoSort

public boolean getNoSort()

Returns whether automatic sorting of the input cursors is disabled.

Returns:

whether automatic sorting of the input cursors is disabled

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, SDatabase.join(com.sleepycat.client.SCursor[], com.sleepycat.client.SJoinConfig) 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 SDatabase.join(com.sleepycat.client.SCursor[], com.sleepycat.client.SJoinConfig).

Parameters:

noSort - whether automatic sorting of the input cursors is disabled