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<b>DbEnv::set_cache_max</b>
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<b><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></b>
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<b>Description: DbEnv::set_cache_max</b>
<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="../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 <a href="../ref/env/db_config.html#DB_CONFIG">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 size in bytes.
Because the <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> 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="../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>
<b>Parameters</b> <br>
<b>mp_mmapsize</b><ul compact><li>The <b>mp_mmapsize</b> parameter is the maximum file size, in bytes,
for a file to be mapped into the process address space.</ul>
<br>
<br><b>Errors</b>
<p>The DbEnv::set_cache_max 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>EINVAL</b><ul compact><li>If the method was called after <a href="../api_cxx/env_open.html">DbEnv::open</a> was called; or if an
invalid flag value or parameter was specified.</ul>
<br>
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<b>Description: DbEnv::get_cache_max</b>
<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>
<b>Parameters</b> <br>
<b>bytesp</b><ul compact><li>The <b>bytesp</b> parameter references memory into which
the additional bytes of memory in the cache is copied.</ul>
<b>gbytesp</b><ul compact><li>The <b>gbytesp</b> parameter references memory into which
the gigabytes of memory in the cache is copied.</ul>
<br>
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<br><b>Class</b>
<a href="../api_cxx/env_class.html">DbEnv</a>
<br><b>See Also</b>
<a href="../api_cxx/env_list.html">Database Environments and Related Methods</a>
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