<!--$Id: db_sync.so,v 10.37 2007/10/24 16:06:06 bostic Exp $--> <!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB: Db::sync</title> <meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> <meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> </head> <body bgcolor=white> <table width="100%"><tr valign=top> <td> <b>Db::sync</b> </td> <td align=right> <a href="../api_cxx/api_core.html"><img src="../images/api.gif" alt="API"></a> <a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a></td> </tr></table> <hr size=1 noshade> <tt> <b><pre> #include <db_cxx.h> <p> int Db::sync(u_int32_t flags); </pre></b> <hr size=1 noshade> <b>Description: Db::sync</b> <p>The Db::sync method flushes any cached information to disk.</p> <p>If the database is in memory only, the Db::sync method has no effect and will always succeed.</p> <p><b>It is important to understand that flushing cached information to disk only minimizes the window of opportunity for corrupted data.</b> Although unlikely, it is possible for database corruption to happen if a system or application crash occurs while writing data to the database. To ensure that database corruption never occurs, applications must either: use transactions and logging with automatic recovery; use logging and application-specific recovery; or edit a copy of the database, and once all applications using the database have successfully called <a href="../api_cxx/db_close.html">Db::close</a>, atomically replace the original database with the updated copy.</p> <p>The Db::sync method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success. </p> <b>Parameters</b> <br> <b>flags</b><ul compact><li>The <b>flags</b> parameter is currently unused, and must be set to 0.</ul> <br> <br><b>Errors</b> <p>The Db::sync method may fail and throw <a href="../api_cxx/except_class.html">DbException</a>, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:</p> <br> <b>DB_REP_HANDLE_DEAD</b><ul compact><li>The database handle has been invalidated because a replication election unrolled a committed transaction.</ul> <br> <br> <b>DB_REP_LOCKOUT</b><ul compact><li>The operation was blocked by client/master synchronization.</ul> <br> <br> <b>EINVAL</b><ul compact><li>An invalid flag value or parameter was specified.</ul> <br> <hr size=1 noshade> <br><b>Class</b> <a href="../api_cxx/db_class.html">Db</a> <br><b>See Also</b> <a href="../api_cxx/db_list.html">Databases and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <a href="../api_cxx/api_core.html"><img src="../images/api.gif" alt="API"></a><a href="../ref/toc.html"><img src="../images/ref.gif" alt="Ref"></a> </td></tr></table> <p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> </body> </html>