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Db::set_h_ffactor
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#include &lt;db_cxx.h&gt;

int
Db::set_h_ffactor(u_int32_t h_ffactor);

int Db::get_h_ffactor(u_int32_t *h_ffactorp);
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Description: Db::set_h_ffactor
Set the desired density within the hash table. If no value is
specified, the fill factor will be selected dynamically as pages are
filled.
The Db::set_h_ffactor method configures a database, not only operations performed
using the specified <a href="../../db4-devel-4.7.25/api_cxx/db_class.html">Db</a> handle.
The Db::set_h_ffactor method may not be called after the <a href="../../db4-devel-4.7.25/api_cxx/db_open.html">Db::open</a> method is called.
If the database already exists when
<a href="../../db4-devel-4.7.25/api_cxx/db_open.html">Db::open</a> is called, the information specified to Db::set_h_ffactor will
be ignored.

The Db::set_h_ffactor 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.

Parameters 
 h_ffactor<ul compact><li>The h_ffactor parameter is the desired density within the hash table.</ul>
The density is an approximation of the number of keys allowed to
accumulate in any one bucket, determining when the hash table grows or
shrinks. If you know the average sizes of the keys and data in your
data set, setting the fill factor can enhance performance. A reasonable
rule computing fill factor is to set it to the following:
<blockquote><pre>(pagesize - 32) / (average_key_size + average_data_size + 8)</pre></blockquote>
 
 Errors
The Db::set_h_ffactor method
may fail and throw
<a href="../../db4-devel-4.7.25/api_cxx/except_class.html">DbException</a>,
encapsulating one of the following non-zero errors, or return one of
the following non-zero errors:
 
EINVAL<ul compact><li>If the method was called after <a href="../../db4-devel-4.7.25/api_cxx/db_open.html">Db::open</a> was called; or if an
invalid flag value or parameter was specified.</ul>
 
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Description: Db::get_h_ffactor
The Db::get_h_ffactor method returns the hash table density.
The Db::get_h_ffactor method may be called at any time during the life of the
application.
The Db::get_h_ffactor 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.

Parameters 
 h_ffactorp<ul compact><li>The Db::get_h_ffactor method returns the
hash table density in h_ffactorp.</ul>
 
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 Class
<a href="../../db4-devel-4.7.25/api_cxx/db_class.html">Db</a>
 See Also
<a href="../../db4-devel-4.7.25/api_cxx/db_list.html">Databases and Related Methods</a>
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