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<h2 class="title" style="clear: both"><a id="mempset_mp_max_write"></a>DbEnv::set_mp_max_write()</h2>
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<pre class="programlisting">#include <db_cxx.h>
int
DbEnv::set_mp_max_write(int maxwrite, db_timeout_t maxwrite_sleep); </pre>
<p>
The <code class="methodname">DbEnv::set_mp_max_write()</code> method limits the number of sequential
write operations scheduled by the library when flushing dirty pages
from the cache.
</p>
<p>
The database environment's maximum number of sequential write
operations 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_mp_max_write", one or more whitespace
characters, and the maximum number of sequential writes and the
number of microseconds to sleep, also separated by whitespace
characters. 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_mp_max_write()</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_mp_max_write()</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="idp8828480"></a>Parameters</h3>
</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp8827832"></a>maxwrite</h4>
</div>
</div>
</div>
<p>
The maximum number of sequential write operations scheduled by the
library when flushing dirty pages from the cache, or 0 if there is no
limitation on the number of sequential write operations.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp8834968"></a>maxwrite_sleep</h4>
</div>
</div>
</div>
<p>
The number of microseconds the thread of control should pause before
scheduling further write operations. It must be specified as an
unsigned 32-bit number of microseconds, limiting the maximum pause to
roughly 71 minutes.
</p>
</div>
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<h3 class="title"><a id="idp8829560"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="methodname">DbEnv::set_mp_max_write()</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="idp8832968"></a>EINVAL</h4>
</div>
</div>
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<p>
An invalid flag value or parameter was specified.
</p>
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<h3 class="title"><a id="idp8797648"></a>Class</h3>
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</div>
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<p>
<a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a>, <a class="link" href="memp.html" title="Chapter 9. The DbMpoolFile Handle">DbMpoolFile</a>
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<h3 class="title"><a id="idp8827616"></a>See Also</h3>
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<a class="xref" href="memp.html#memplist" title="Memory Pools and Related Methods">Memory Pools and Related Methods</a>
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