Sindbad~EG File Manager
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<h2 class="title" style="clear: both"><a id="set_blob_threshold"></a>
<span>Db::set_ext_file_threshold()</span>
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<pre class="programlisting">#include <db_cxx.h>
int
Db::set_ext_file_threshold(u_int32_t bytes, u_int32_t flags); </pre>
<p>
The <code class="methodname">Db::set_ext_file_threshold()</code> method sets
a size 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
files will never be used by the database.
</p>
<p>
It is illegal to set an external file threshold if any of the
following flags were specified for the database:
<a class="link" href="dbset_flags.html#dbset_flags_DB_DUP">DB_DUP</a>, and
<a class="link" href="dbset_flags.html#dbset_flags_DB_DUPSORT">DB_DUPSORT</a>.
</p>
<p>
It is also illegal to set an external file threshold if compression is
turned on for the database. That is, if <a class="xref" href="dbset_bt_compress.html" title="Db::set_bt_compress()">
<span>Db::set_bt_compress()</span>
</a> has
been called for the database handle.
</p>
<p>
This method configures the underlying database. The external file
threshold is stored in the database at database creation time. Any
external file threshold set after creating the database is ignored.
</p>
<p>
This method may not be called after <a class="xref" href="dbopen.html" title="Db::open()">
<span>Db::open()</span>
</a> is called.
</p>
<p>
Unless otherwise specified, the
<code class="methodname">Db::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>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
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<h3 class="title"><a id="idm139755608761808"></a>Parameters</h3>
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<div class="sect3" lang="en" xml:lang="en">
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<h4 class="title"><a id="idm139755608762096"></a>bytes</h4>
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</div>
<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>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idm139755608788192"></a>flags</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>flags</strong></span> parameter must be set to 0.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idm139755608770352"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="methodname">Db::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>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idm139755608788944"></a>EINVAL</h4>
</div>
</div>
</div>
<p>
If the method was called after <a class="xref" href="dbopen.html" title="Db::open()">
<span>Db::open()</span>
</a> was called; or if
an invalid flag or parameter was specified; or if
compression is turned on for the database; or if the
database is configured with one or more of the following
flags:
<a class="link" href="dbset_flags.html#dbset_flags_DB_DUP">DB_DUP</a>, and
<a class="link" href="dbset_flags.html#dbset_flags_DB_DUPSORT">DB_DUPSORT</a>.
</p>
</div>
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<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idm139755608752384"></a>Class</h3>
</div>
</div>
</div>
<p>
<a class="link" href="db.html" title="Chapter 2. The Db Handle">Db</a>
</p>
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<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idm139755608757248"></a>See Also</h3>
</div>
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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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