I am not very familiar with Berkeley DB . I was trying to delete an entry from database. i am able to insert to the database and view the database. For viewing entries i used the command
symbolsByName.subIndex(symbolName).entities();
where symbolsByName is a secondary index and symbolName is the search string.
for deletion i used this command.
boolean b=symbolsByName.delete(symbolName);
the function returned true value. But that entry is still in the databse.