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<title>Berkeley DB Reference Guide: Log file limits</title>
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<td><h3><dl><dt>Berkeley DB Reference Guide:<dd>Logging Subsystem</dl></h3></td>
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<h1 align=center>Log file limits</h1>
<p>Log file names and sizes impose a limit on how long databases may be
used in a Berkeley DB database environment. It is quite unlikely that an
application will reach this limit, however, if the limit is reached,
the Berkeley DB environment's databases must be dumped and reloaded.
<p>The log file name consists of <b>log.</b> followed by 10 digits, with
a maximum of 2,000,000,000 log files. Consider an application performing
6000 transactions per second, for 24 hours a day, logged into 10MB log
files, where each transaction is logging approximately 500 bytes of data.
The calculation:
<p><blockquote><pre>(10 * 2^20 * 2000000000) / (6000 * 500 * 365 * 60 * 60 * 24) = ~221</pre></blockquote>
<p>indicates that the system will run out of log file names in roughly 221
years.
<p>There is no way to reset the log file name space in Berkeley DB. If your
application is reaching the end of its log file name space, you must:
<p><ol>
<p><li>Archive your databases as if to prepare for catastrophic failure (see
<a href="../../utility/db_archive.html">db_archive</a> for more information).
<p><li>Dump and re-load all your databases (see <a href="../../utility/db_dump.html">db_dump</a> and
<a href="../../utility/db_load.html">db_load</a> for more information).
<p><li>Remove all of the log files from the database environment. Note, this
is the only situation where all of the log files are removed from an
environment, in all other cases at least a single log file is
retained.
<p><li>Restart your application.
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