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<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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Binary Large Objects
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<div class="sect1" lang="en" xml:lang="en">
<div class="titlepage">
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<div>
<h2 class="title" style="clear: both"><a id="set_blob_threshold"></a>DB->set_blob_threshold()</h2>
</div>
</div>
</div>
<pre class="programlisting">#include <db.h>
int
DB->set_blob_threshold(DB *db, u_int32_t bytes, u_int32_t flags); </pre>
<p>
The <code class="methodname">DB->set_blob_threshold()</code> method sets
a size which is used to determine when a data item will be
stored as a BLOB. 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 BLOBs
will never be used by the database.
</p>
<p>
It is illegal to set a BLOB threshold if any of the following flags
were specified for the database:
<a class="link" href="dbset_flags.html#dbset_flags_DB_CHKSUM">DB_CHKSUM</a>,
<a class="link" href="dbset_flags.html#dbset_flags_DB_ENCRYPT">DB_ENCRYPT</a>,
<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 a BLOB 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()">DB->set_bt_compress()</a> has
been called for the database handle.
</p>
<p>
This method configures the underlying database. The BLOB threshold
is stored in the database at database creation time. Any BLOB
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()">DB->open()</a> is called.
</p>
<p>
Unless otherwise specified, the
<code class="methodname">DB->set_blob_threshold()</code> <span>
<span>
method returns a non-zero error value on failure and 0 on success.
</span>
</span>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp4799520"></a>Parameters</h3>
</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp4800184"></a>bytes</h4>
</div>
</div>
</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 a BLOB.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp4789296"></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="idp4784864"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="methodname">DB->set_blob_threshold()</code> <span>
<span>
method may fail and 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="idp4799688"></a>EINVAL</h4>
</div>
</div>
</div>
<p>
If the method was called after <a class="xref" href="dbopen.html" title="DB->open()">DB->open()</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_CHKSUM">DB_CHKSUM</a>,
<a class="link" href="dbset_flags.html#dbset_flags_DB_ENCRYPT">DB_ENCRYPT</a>,
<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>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp4808696"></a>Class</h3>
</div>
</div>
</div>
<p>
<a class="link" href="db.html" title="Chapter 2. The DB Handle">DB</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="idp4806272"></a>See Also</h3>
</div>
</div>
</div>
<p>
<a class="xref" href="blob.html#bloblist" title="BLOBs and Related Methods">BLOBs and Related Methods</a>
</p>
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