<!--$Id: nosync.so,v 1.7 2004/09/28 14:13:09 bostic Exp $--> <!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB Reference Guide: Release 4.2: Client replication environments</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><dl><dt>Berkeley DB Reference Guide:<dd>Upgrading Berkeley DB Applications</dl></b></td> <td align=right><a href="../upgrade.4.2/repinit.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../upgrade.4.2/tcl.html"><img src="../../images/next.gif" alt="Next"></a> </td></tr></table> <p align=center><b>Release 4.2: Client replication environments</b></p> <p>In previous Berkeley DB releases, replication clients always behaved as if <a href="../../api_c/env_set_flags.html#DB_TXN_NOSYNC">DB_TXN_NOSYNC</a> behavior was configured, that is, clients would not write or synchronously flush their log when receiving a transaction commit or prepare message. However, applications needing a high level of transactional guarantee may need a write and synchronous flush on the client. By default in the Berkeley DB 4.2 release, client database environments write and synchronously flush their logs when receiving a transaction commit or prepare message. Applications not needing such a high level of transactional guarantee should use the environment's <a href="../../api_c/env_set_flags.html#DB_TXN_NOSYNC">DB_TXN_NOSYNC</a> flag to configure their client database environments to not do the write or flush on transaction commit, as this will increase their performance. Regardless of the setting of the <a href="../../api_c/env_set_flags.html#DB_TXN_NOSYNC">DB_TXN_NOSYNC</a> flag, clients will always write and flush on transaction prepare.</p> <table width="100%"><tr><td><br></td><td align=right><a href="../upgrade.4.2/repinit.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../upgrade.4.2/tcl.html"><img src="../../images/next.gif" alt="Next"></a> </td></tr></table> <p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> </body> </html>