<!--$Id: env_set_cache_max.so,v 1.2 2007/07/07 14:40:15 bostic Exp $--> <!--Copyright (c) 1997,2007 Oracle. All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB: DbEnv::set_cache_max</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> <h3>DbEnv::set_cache_max</h3> </td> <td align=right> <a href="../../db46-devel-4.6.21/api_cxx/api_core.html"><img src="../../db46-devel-4.6.21/images/api.gif" alt="API"></a> <a href="../../db46-devel-4.6.21/ref/toc.html"><img src="../../db46-devel-4.6.21/images/ref.gif" alt="Ref"></a></td> </tr></table> <hr size=1 noshade> <tt> <h3><pre> #include <db_cxx.h> <p> int DbEnv::set_cache_max(u_int32_t gbytes, u_int32_t bytes); <p> int DbEnv::get_cache_max(u_int32_t *gbytesp, u_int32_t *bytesp); </pre></h3> <hr size=1 noshade> <h3>Description: DbEnv::set_cache_max</h3> <p>The DbEnv::set_cache_max method sets the maximum cache size, in bytes. The specified size is rounded to the nearest multiple of the cache region size, which is the initial cache size divided by the number of regions specified to the <a href="../../db46-devel-4.6.21/api_cxx/env_set_cachesize.html">DbEnv::set_cachesize</a> method. If no value is specified, it defaults to the initial cache size.</p> <p>The database environment's maximum cache size may also be configured using the environment's <b>DB_CONFIG</b> file. The syntax of the entry in that file is a single line with the string "set_cache_max", one or more whitespace characters, and the size in bytes. Because the <b>DB_CONFIG</b> file is read when the database environment is opened, it will silently overrule configuration done before that time.</p> <p>The DbEnv::set_cache_max method configures a database environment, not only operations performed using the specified <a href="../../db46-devel-4.6.21/api_cxx/env_class.html">DbEnv</a> handle.</p> <p>The DbEnv::set_cache_max method may be called at any time during the life of the application.</p> <p>The DbEnv::set_cache_max 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> <h3>Parameters</h3> <dl compact> <dt><b>mp_mmapsize</b><dd>The <b>mp_mmapsize</b> parameter is the maximum file size, in bytes, for a file to be mapped into the process address space. </dl> <h3>Errors</h3> <p>The DbEnv::set_cache_max method may fail and throw <a href="../../db46-devel-4.6.21/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> <dl compact> <dt>EINVAL<dd>If the method was called after <a href="../../db46-devel-4.6.21/api_cxx/env_open.html">DbEnv::open</a> was called; or if an invalid flag value or parameter was specified. </dl> <hr size=1 noshade> <h3>Description: DbEnv::get_cache_max</h3> <p>The DbEnv::get_cache_max method returns the maximum size of the cache.</p> <p>The DbEnv::get_cache_max method may be called at any time during the life of the application.</p> <p>The DbEnv::get_cache_max 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> <h3>Parameters</h3> <dl compact> <dt><b>bytesp</b><dd>The <b>bytesp</b> parameter references memory into which the additional bytes of memory in the cache is copied. <dt><b>gbytesp</b><dd>The <b>gbytesp</b> parameter references memory into which the gigabytes of memory in the cache is copied. </dl> <hr size=1 noshade> <h3>Class</h3> <a href="../../db46-devel-4.6.21/api_cxx/env_class.html">DbEnv</a> <h3>See Also</h3> <a href="../../db46-devel-4.6.21/api_cxx/env_list.html">Database Environments and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <a href="../../db46-devel-4.6.21/api_cxx/api_core.html"><img src="../../db46-devel-4.6.21/images/api.gif" alt="API"></a><a href="../../db46-devel-4.6.21/ref/toc.html"><img src="../../db46-devel-4.6.21/images/ref.gif" alt="Ref"></a> </td></tr></table> <p><font size=1>Copyright (c) 1996,2007 Oracle. All rights reserved.</font> </body> </html>