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Release 5.2.28 on 6/10/2011
2011-09-13 17:44:24 +00:00
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<th colspan="3" align="center">DbEnv::log_get_config()</th>
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<td width="20%" align="left"><a accesskey="p" href="logflush.html">Prev</a> </td>
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The DbLsn Handle
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<div class="sect1" lang="en" xml:lang="en">
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<h2 class="title" style="clear: both"><a id="envlog_get_config"></a>DbEnv::log_get_config()</h2>
</div>
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</div>
<pre class="programlisting">#include &lt;db_cxx.h&gt;
int
DbEnv::log_get_config(u_int32_t which, int *onoffp)</pre>
<p>
The <code class="methodname">DbEnv::log_get_config()</code> method returns whether the specified
<span class="bold"><strong>which</strong></span> parameter is currently set or
not. You can manage this value using the
<a class="xref" href="envlog_set_config.html" title="DbEnv::log_set_config()">DbEnv::log_set_config()</a>
method.
</p>
<p>
The <code class="methodname">DbEnv::log_get_config()</code> method may be called at any time during
the life of the application.
</p>
<p>
The <code class="methodname">DbEnv::log_get_config()</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">
<div>
<div>
Release 5.2.36 on 9/14/2022
2011-12-20 00:07:10 +00:00
<h3 class="title"><a id="id3619270"></a>Parameters</h3>
Release 5.2.28 on 6/10/2011
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</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
Release 5.2.36 on 9/14/2022
2011-12-20 00:07:10 +00:00
<h4 class="title"><a id="id3619259"></a>which</h4>
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</div>
</div>
</div>
<p>
The <span class="bold"><strong>which</strong></span> parameter is the message
value for which configuration is being checked. Must be set to one of the following values:
</p>
<div class="itemizedlist">
<ul type="disc">
<li>
<p><a id="log_get_config_DB_LOG_DIRECT"></a>
<code class="literal">DB_LOG_DIRECT</code>
</p>
<p>
System buffering is turned off for Berkeley DB log files to avoid double
caching.
</p>
</li>
<li>
<p><a id="log_get_config_DB_LOG_DSYNC"></a>
<code class="literal">DB_LOG_DSYNC</code>
</p>
<p>
Berkeley DB is configured to flush log writes to the backing disk before
returning from the write system call, rather than flushing log writes
explicitly in a separate system call, as necessary.
</p>
</li>
<li>
<p><a id="log_get_config_DB_LOG_AUTO_REMOVE"></a>
<code class="literal">DB_LOG_AUTO_REMOVE</code>
</p>
<p>
Berkeley DB automatically removes log files that are no
longer needed.
</p>
</li>
<li>
<p><a id="log_get_config_DB_LOG_IN_MEMORY"></a>
<code class="literal">DB_LOG_IN_MEMORY</code>
</p>
<p>
Transaction logs are maintained in memory rather than on disk. This
means that transactions exhibit the ACI (atomicity, consistency, and
isolation) properties, but not D (durability).
</p>
</li>
<li>
<p><a id="log_get_config_DB_LOG_ZERO"></a>
<code class="literal">DB_LOG_ZERO</code>
</p>
<p>
All pages of a log file are zeroed when that log file is created.
</p>
</li>
</ul>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
Release 5.2.36 on 9/14/2022
2011-12-20 00:07:10 +00:00
<h4 class="title"><a id="id3619450"></a>onoffp</h4>
Release 5.2.28 on 6/10/2011
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</div>
</div>
</div>
<p>
The <span class="bold"><strong>onoffp</strong></span> parameter references
memory into which the configuration of the specified <span class="bold"><strong>which</strong></span> parameter is copied.
</p>
<p>
If the returned <span class="bold"><strong>onoff</strong></span> value is zero, the
parameter is off; otherwise, on.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
Release 5.2.36 on 9/14/2022
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<h3 class="title"><a id="id3619454"></a>Class</h3>
Release 5.2.28 on 6/10/2011
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</div>
</div>
</div>
<p>
<a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
Release 5.2.36 on 9/14/2022
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<h3 class="title"><a id="id3619277"></a>See Also</h3>
Release 5.2.28 on 6/10/2011
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</div>
</div>
</div>
<p>
<a class="xref" href="lsn.html#loglist" title="Logging Subsystem and Related Methods">Logging Subsystem and Related Methods</a>,
<a class="xref" href="envlog_set_config.html" title="DbEnv::log_set_config()">DbEnv::log_set_config()</a>
</p>
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