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<h1>DbEnv.set_tx_recover</h1>
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<h3><pre>
import com.sleepycat.db.*;
<p>
public interface DbTxnRecover
{
public abstract int
tx_recover(DbEnv dbenv, Dbt log_rec, DbLsn lsn, int op);
}
public class DbEnv
{
public void set_tx_recover(DbTxnRecover tx_recover)
throws DbException;
...
}
</pre></h3>
<h1>Description</h1>
<p>Set the application's method to be called during transaction abort
and recovery. This method must return 0 on success and either
<b>errno</b> or a value outside of the Berkeley DB error name space on
failure. It takes four arguments:
<p><dl compact>
<p><dt>dbenv <dd>A Berkeley DB environment.
<p><dt>log_rec<dd>A log record.
<p><dt>lsn<dd>A log sequence number.
<p><dt>op<dd>One of the following values:
<p><dl compact>
<p><dt><a name="Db.DB_TXN_BACKWARD_ROLL">Db.DB_TXN_BACKWARD_ROLL</a><dd>The log is being read backward to determine which transactions have been
committed and to abort those operations that were not; undo the operation
described by the log record.
<p><dt><a name="Db.DB_TXN_FORWARD_ROLL">Db.DB_TXN_FORWARD_ROLL</a><dd>The log is being played forward; redo the operation described by the log
record.
<p><dt><a name="Db.DB_TXN_ABORT">Db.DB_TXN_ABORT</a><dd>The log is being read backward during a transaction abort; undo the
operation described by the log record.
<p><dt><a name="Db.DB_TXN_APPLY">Db.DB_TXN_APPLY</a><dd>The log is being applied on a replica site; redo the operation
described by the log record.
</dl>
</dl>
<p>The Db.DB_TXN_FORWARD_ROLL and Db.DB_TXN_APPLY operations
frequently imply the same actions, redoing changes that appear in the
log record. The macro DB_REDO(op) checks that the operation is one of
Db.DB_TXN_FORWARD_ROLL or Db.DB_TXN_APPLY, and should be used
in the recovery code to refer to the conditions under which operations
should be redone. Similarly, the macro DB_UNDO(op) checks if the
operation is one of Db.DB_TXN_BACKWARD_ROLL or Db.DB_TXN_ABORT.
<p>The DbEnv.set_tx_recover interface may be used only to configure Berkeley DB before
the <a href="../../db4-devel-4.0.14/api_java/env_open.html">DbEnv.open</a> interface is called.
<p>The DbEnv.set_tx_recover method throws an exception that encapsulates a non-zero error value on
failure.
<h1>Errors</h1>
<p>The DbEnv.set_tx_recover method may fail and throw an exception encapsulating a non-zero error for the following conditions:
<p><dl compact>
<p><dt>EINVAL<dd>An invalid flag value or parameter was specified.
<p>Called after <a href="../../db4-devel-4.0.14/api_java/env_open.html">DbEnv.open</a> was called.
</dl>
<p>The DbEnv.set_tx_recover method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods.
If a catastrophic error has occurred, the DbEnv.set_tx_recover method may fail and throw
a <a href="../../db4-devel-4.0.14/api_java/runrec_class.html">DbRunRecoveryException</a>, in which case all subsequent Berkeley DB calls
will fail in the same way.
<h1>Class</h1>
<a href="../../db4-devel-4.0.14/api_java/dbenv_class.html">DbEnv</a>, <a href="../../db4-devel-4.0.14/api_java/txn_class.html">DbTxn</a>
<h1>See Also</h1>
<a href="../../db4-devel-4.0.14/api_java/env_set_tx_max.html">DbEnv.set_tx_max</a>,
<a href="../../db4-devel-4.0.14/api_java/env_set_tx_timestamp.html">DbEnv.set_tx_timestamp</a>,
<a href="../../db4-devel-4.0.14/api_java/txn_abort.html">DbTxn.abort</a>,
<a href="../../db4-devel-4.0.14/api_java/txn_begin.html">DbEnv.txn_begin</a>,
<a href="../../db4-devel-4.0.14/api_java/txn_checkpoint.html">DbEnv.txn_checkpoint</a>,
<a href="../../db4-devel-4.0.14/api_java/txn_commit.html">DbTxn.commit</a>,
<a href="../../db4-devel-4.0.14/api_java/txn_discard.html">DbTxn.discard</a>,
<a href="../../db4-devel-4.0.14/api_java/txn_id.html">DbTxn.id</a>,
<a href="../../db4-devel-4.0.14/api_java/txn_prepare.html">DbTxn.prepare</a>,
<a href="../../db4-devel-4.0.14/api_java/txn_recover.html">DbEnv.txn_recover</a>,
<a href="../../db4-devel-4.0.14/api_java/txn_set_timeout.html">DbTxn.set_timeout</a>
and
<a href="../../db4-devel-4.0.14/api_java/txn_stat.html">DbEnv.txn_stat</a>.
</tt>
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