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<h2 class="title" style="clear: both"><a id="envset_blob_threshold"></a>
<span>DbEnv::set_ext_file_threshold()</span>
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<pre class="programlisting">#include <db_cxx.h>
int
DbEnv::set_ext_file_threshold(u_int32_t bytes, u_int32_t flags); </pre>
<p>
The <code class="methodname">DbEnv::set_ext_file_threshold()</code> method sets
a default size for the environment which is used to determine when
a data item will be stored as an external file. Data items sized less
than this threshold are stored as normal data within the database. Data
items larger than this size are stored on-disk in a subdirectory
set aside for the purpose.
</p>
<p>
If this threshold value is set to <code class="literal">0</code>, then external
file support is turned off by default for databases created in the
environment. If this method is never called, then the default external
file threshold is <code class="literal">0</code>.
</p>
<p>
This method only sets the default external file threshold for the
environment. The external file threshold can be set for individual
databases created within the environment using
<a class="xref" href="set_blob_threshold.html" title="Db::set_ext_file_threshold()">
<span>Db::set_ext_file_threshold()</span>
</a>.
</p>
<p>
This method configures operations performed using the specified
<a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a> handle, not all operations
performed on the underlying database environment.
</p>
<p>
You may call this method at any time after the DbEnv handle
has been created.
</p>
<p>
Unless otherwise specified, the
<code class="methodname">DbEnv::set_ext_file_threshold()</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>
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<div class="sect2" lang="en" xml:lang="en">
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<h3 class="title"><a id="idm139755608563472"></a>Parameters</h3>
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<h4 class="title"><a id="idm139755608563152"></a>bytes</h4>
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<p>
The <span class="bold"><strong>bytes</strong></span> parameter
identifies the threshold size, in bytes, beyond which a
data item is stored as an external file.
</p>
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<h4 class="title"><a id="idm139755608588896"></a>flags</h4>
</div>
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<p>
The <span class="bold"><strong>flags</strong></span> parameter must be
set to 0.
</p>
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<h3 class="title"><a id="idm139755608574064"></a>Errors</h3>
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<p>
The <code class="methodname">DbEnv::set_ext_file_threshold()</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>
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<h4 class="title"><a id="idm139755608548048"></a>EINVAL</h4>
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<p>
If an invalid flag or parameter was specified.
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<div class="sect2" lang="en" xml:lang="en">
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<h3 class="title"><a id="idm139755608551024"></a>Class</h3>
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<p>
<a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a>
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<h3 class="title"><a id="idm139755608558784"></a>See Also</h3>
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<p>
<a class="xref" href="blob.html#bloblist" title="External Files and Related Methods">External Files and Related Methods</a>
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