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18          <th colspan="3" align="center">Secondary Indices with Transaction Applications</th>
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32            <h2 class="title" style="clear: both"><a id="txnindices"></a>Secondary Indices with Transaction Applications</h2>
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34        </div>
35        <div></div>
36      </div>
37      <p>
38            
39            <span>
40                If you are using the base API, then you
41            </span>
42
43                can use transactions with your secondary indices so long as you
44
45            
46
47            <span>
48                open the secondary index so that it is transactional. 
49            </span>
50                
51            
52        </p>
53      <p>
54            All other aspects of using secondary indices with transactions are
55            identical to using secondary indices without transactions. In
56            addition, transaction-protecting 
57                
58                <span>
59                    secondary cursors is performed just as you protect normal
60                    cursors — you simply have to make sure the cursor is
61                    opened using a transaction handle, and that the cursor is
62                    closed before the handle is either either committed or
63                    aborted.
64                </span>
65                    See <a href="txncursor.html">Transactional Cursors</a> for details.
66        </p>
67      <p>
68            Note that when you use transactions to protect your database writes, your secondary indices are protected from
69            corruption because updates to the primary and the secondaries are performed in a single atomic transaction.
70        </p>
71      <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
72        <h3 class="title">Note</h3>
73        <p>
74                            If you are using the DPL, then be aware that
75                            you never have to provide a transactional
76                            handle when opening an index, be it a primary
77                            or a secondary. However, transactions are
78                            enabled for your store, then all of the indexes
79                            that you open will be enabled for transactional
80                            usage. More, any write operation performed
81                            using that index will be done using a
82                            transaction, regardless of whether you
83                            explictly provide a transactional handle to the
84                            write operation.
85                    </p>
86        <p>
87                            If you do not explictly provide a transaction
88                            handle to DPL write operations performed on a
89                            transactional store, then auto commit is
90                            silently used for that operation.
91                    </p>
92      </div>
93      <p>
94            For example:
95        </p>
96      <pre class="programlisting">package db.GettingStarted;
97
98import com.sleepycat.bind.tuple.TupleBinding;
99import com.sleepycat.db.Database;
100import com.sleepycat.db.DatabaseType;
101import com.sleepycat.db.DatabaseConfig;
102import com.sleepycat.db.DatabaseException;
103import com.sleepycat.db.Environment;
104import com.sleepycat.db.EnvironmentConfig;
105import com.sleepycat.db.SecondaryDatabase;
106import com.sleepycat.db.SecondaryConfig;
107
108import java.io.FileNotFoundException;
109
110...
111
112// Environment and primary database opens omitted.
113
114SecondaryConfig mySecConfig = new SecondaryConfig();
115mySecConfig.setAllowCreate(true);
116mySecConfig.setType(DatabaseType.BTREE);
117mySecConfig.setTransactional(true);
118
119SecondaryDatabase mySecDb = null;
120try {
121    // A fake tuple binding that is not actually implemented anywhere.
122    // The tuple binding is dependent on the data in use.
123    // See the Getting Started Guide for details
124    TupleBinding myTupleBinding = new MyTupleBinding();
125
126    // Open the secondary. FullNameKeyCreator is not actually implemented
127    // anywhere. See the Getting Started Guide for details.
128    FullNameKeyCreator keyCreator = new FullNameKeyCreator(myTupleBinding);
129
130    // Set the key creator on the secondary config object.
131    mySecConfig.setKeyCreator(keyCreator);
132
133    // Perform the actual open. Because this database is configured to be
134    // transactional, the open is automatically wrapped in a transaction.
135    //      - myEnv is the environment handle.
136    //      - myDb is the primary database handle.
137    String secDbName = "mySecondaryDatabase";
138    mySecDb = myEnv.openSecondary(null, secDbName, null, myDb, mySecConfig);
139} catch (DatabaseException de) {
140    // Exception handling goes here ...
141} catch (FileNotFoundException fnfe) {
142    // Exception handling goes here ...
143}</pre>
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