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<h2 class="title" style="clear: both"><a id="dbset_pagesize"></a>Db::set_pagesize()</h2>
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<pre class="programlisting">#include <db_cxx.h>
int
Db::set_pagesize(u_int32_t pagesize); </pre>
<p>
Set the size of the pages used to hold items in the database, in
bytes. The minimum page size is 512 bytes, the maximum page size is
64K bytes, and the page size must be a power-of-two. If the page size
is not explicitly set, one is selected based on the underlying
filesystem I/O block size. The automatically selected size has a
lower limit of 512 bytes and an upper limit of 16K bytes.
</p>
<p>
For information on tuning the Berkeley DB page size, see
<a href="../../programmer_reference/general_am_conf.html#am_conf_pagesize" class="olink">Selecting a page size</a>.
</p>
<p>
The <code class="methodname">Db::set_pagesize()</code> method configures
a database, not only operations performed using the specified
<a class="link" href="db.html" title="Chapter 2. The Db Handle">Db</a> handle.
</p>
<p>
The <code class="methodname">Db::set_pagesize()</code> method may not be
called after the <a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a>
method is called. If the database already exists when
<a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a> is called, the
information specified to
<code class="methodname">Db::set_pagesize()</code> will be ignored.
</p>
<p>
If creating additional databases in a single physical file,
information specified to
<code class="methodname">Db::set_pagesize()</code> will be ignored and
the page size of the existing databases will be used.
</p>
<p>
The <code class="methodname">Db::set_pagesize()</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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<div>
<h3 class="title"><a id="idp351376"></a>Parameters</h3>
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<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="idp350728"></a>pagesize</h4>
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<p>
The <span class="bold"><strong>pagesize</strong></span> parameter sets the
database page size.
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<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
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<h3 class="title"><a id="idp346632"></a>Errors</h3>
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<p>
The <code class="methodname">Db::set_pagesize()</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>
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<div class="sect3" lang="en" xml:lang="en">
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<h4 class="title"><a id="idp362480"></a>EINVAL</h4>
</div>
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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 value or parameter was specified.
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<h3 class="title"><a id="idp363808"></a>Class</h3>
</div>
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<a class="link" href="db.html" title="Chapter 2. The Db Handle">Db</a>
</p>
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<h3 class="title"><a id="idp352024"></a>See Also</h3>
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<a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a>
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