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<h2 class="title" style="clear: both"><a id="envset_cache_max"></a>DbEnv::set_cache_max()</h2>
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<pre class="programlisting">#include <db_cxx.h>
int
DbEnv::set_cache_max(u_int32_t gbytes, u_int32_t bytes); </pre>
<p>
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 class="xref" href="envset_cachesize.html" title="DbEnv::set_cachesize()">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 <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> 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
maximum cache size in bytes, specified in two parts: the gigabytes
of cache and the additional bytes of cache. Because the
<a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file is read when the database environment is opened,
it will silently overrule configuration done before that time.
</p>
<p>
The <code class="methodname">DbEnv::set_cache_max()</code> method configures a database environment,
not only operations performed using the specified
<a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a> handle.
</p>
<p>
The <code class="methodname">DbEnv::set_cache_max()</code> method must be
called prior to opening the database environment.
</p>
<p>
The <code class="methodname">DbEnv::set_cache_max()</code> <span>
<span>
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.
</span>
</span>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
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<h3 class="title"><a id="idp3423456"></a>Parameters</h3>
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<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp3422808"></a>gbytes</h4>
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</div>
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<p>
The <span class="bold"><strong>gbytes</strong></span> parameter specifies the number of
bytes which, when added to the <span class="bold"><strong>bytes</strong></span>
parameter, specifies the maximum size of the cache.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp3403312"></a>bytes</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>bytes</strong></span> parameter specifies the number of
bytes which, when added to the <span class="bold"><strong>gbytes</strong></span>
parameter, specifies the maximum size of the cache.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp3425616"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="methodname">DbEnv::set_cache_max()</code> <span>
<span>
method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a>
exception, encapsulating one of the following non-zero errors, or return one
of the following non-zero errors:
</span>
</span>
</p>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp3432848"></a>EINVAL</h4>
</div>
</div>
</div>
<p>
An invalid flag value or parameter was specified.
</p>
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<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
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<div>
<h3 class="title"><a id="idp3430872"></a>Class</h3>
</div>
</div>
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<p>
<a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a>
</p>
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<div class="sect2" lang="en" xml:lang="en">
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<h3 class="title"><a id="idp3426408"></a>See Also</h3>
</div>
</div>
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<a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a>
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