Berkeley DB XML
version 2.5.16

Interface SecondaryKeyCreator

All Known Implementing Classes:
SerialSerialKeyCreator, TupleSerialKeyCreator, TupleSerialMarshalledKeyCreator, TupleTupleKeyCreator, TupleTupleMarshalledKeyCreator

public interface SecondaryKeyCreator

The interface implemented for extracting single-valued secondary keys from primary records.

The key creator object is specified by calling SecondaryConfig.setKeyCreator. The secondary database configuration is specified when calling Environment.openSecondaryDatabase.

For example:

    class MyKeyCreator implements SecondaryKeyCreator {
        public boolean createSecondaryKey(SecondaryDatabase secondary,
                                            DatabaseEntry key,
                                            DatabaseEntry data,
                                            DatabaseEntry result)
            throws DatabaseException {
            // DO HERE: Extract the secondary key from the primary key and
            // data, and set the secondary key into the result parameter.
            return true;
    SecondaryConfig secConfig = new SecondaryConfig();
    secConfig.setKeyCreator(new MyKeyCreator());
    // Now pass secConfig to Environment.openSecondaryDatabase

Method Summary
 boolean createSecondaryKey(SecondaryDatabase secondary, DatabaseEntry key, DatabaseEntry data, DatabaseEntry result)
          Creates a secondary key entry, given a primary key and data entry.

Method Detail


boolean createSecondaryKey(SecondaryDatabase secondary,
                           DatabaseEntry key,
                           DatabaseEntry data,
                           DatabaseEntry result)
                           throws DatabaseException
Creates a secondary key entry, given a primary key and data entry.

A secondary key may be derived from the primary key, primary data, or a combination of the primary key and data. For secondary keys that are optional, the key creator method may return false and the key/data pair will not be indexed. To ensure the integrity of a secondary database the key creator method must always return the same result for a given set of input parameters.

secondary - the database to which the secondary key will be added. This parameter is passed for informational purposes but is not commonly used.

key - the primary key entry. This parameter must not be modified by this method.

data - the primary data entry. This parameter must not be modified by this method.

result - the secondary key created by this method.

true if a key was created, or false to indicate that the key is not present.

DatabaseException - if an error occurs attempting to create the secondary key.

Berkeley DB XML
version 2.5.16

Copyright (c) 1996,2009 Oracle. All rights reserved.