2
<!--Copyright 1997-2002 by Sleepycat Software, Inc.-->
3
<!--All rights reserved.-->
4
<!--See the file LICENSE for redistribution information.-->
7
<title>Berkeley DB Reference Guide: Duplicating a cursor</title>
8
<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
9
<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++">
12
<a name="2"><!--meow--></a><a name="3"><!--meow--></a>
13
<table width="100%"><tr valign=top>
14
<td><h3><dl><dt>Berkeley DB Reference Guide:<dd>Access Methods</dl></h3></td>
15
<td align=right><a href="../../ref/am/curdel.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../reftoc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/am/join.html"><img src="../../images/next.gif" alt="Next"></a>
18
<h1 align=center>Duplicating a cursor</h1>
19
<p>Once a cursor has been initialized (for example, by a call to
20
<a href="../../api_c/dbc_get.html">DBcursor->c_get</a>), it can be thought of as identifying a particular
21
location in a database. The <a href="../../api_c/dbc_dup.html">DBcursor->c_dup</a> method permits an application to
22
create a new cursor that has the same locking and transactional
23
information as the cursor from which it is copied, and which optionally
24
refers to the same position in the database.
25
<p>In order to maintain a cursor position when an application is using
26
locking, locks are maintained on behalf of the cursor until the cursor is
27
closed. In cases when an application is using locking without
28
transactions, cursor duplication is often required to avoid
29
self-deadlocks. For further details, refer to
30
<a href="../../ref/lock/am_conv.html">Access method locking conventions</a>.
31
<table width="100%"><tr><td><br></td><td align=right><a href="../../ref/am/curdel.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../reftoc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/am/join.html"><img src="../../images/next.gif" alt="Next"></a>
33
<p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font>