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<title>Berkeley DB Reference Guide: Hash table size</title>
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<td><h3><dl><dt>Berkeley DB Reference Guide:<dd>Access Methods</dl></h3></td>
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<h1 align=center>Hash table size</h1>
<p>When setting up the hash database, knowing the expected number of elements
that will be stored in the hash table is useful. This value can be used
by the Hash access method implementation to more accurately construct the
necessary number of buckets that the database will eventually require.
<p>The anticipated number of elements in the hash table can be specified by
calling the <a href="../../api_c/db_set_h_nelem.html">DB->set_h_nelem</a> function. If not specified, or set too low,
hash tables will expand gracefully as keys are entered, although a slight
performance degradation may be noticed. In order for the estimated number
of elements to be a useful value to Berkeley DB, the <a href="../../api_c/db_set_h_ffactor.html">DB->set_h_ffactor</a> function
must also be called to set the page fill factor.
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