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<title>Berkeley DB: db_checkpoint</title>
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<b>db_checkpoint</b>
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<b><pre>db_checkpoint [<b>-1Vv</b>] [<b>-h home</b>]
[<b>-k kbytes</b>] [<b>-L file</b>] [<b>-P password</b>] [<b>-p min</b>]</pre></b>
<b>Description</b>
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<p>The db_checkpoint utility is a daemon process that monitors the
database log, and periodically calls <a href="../api_c/txn_checkpoint.html">DB_ENV->txn_checkpoint</a> to checkpoint
it.</p>
<p>The options are as follows:</p>
<br>
<b>-1</b><ul compact><li>Force a single checkpoint of the log (regardless of whether or not there
has been activity since the last checkpoint), and then exit.
<p>
When the <b>-1</b> flag is specified, the db_checkpoint
utility will checkpoint the log even if unable to find an existing
database environment. This functionality is useful when upgrading
database environments from one version of Berkeley DB to another.</p></ul>
<b>-h</b><ul compact><li>Specify a home directory for the database environment; by
default, the current working directory is used.</ul>
<b>-k</b><ul compact><li>Checkpoint the database at least as often as every <b>kbytes</b> of log
file are written.</ul>
<b>-L</b><ul compact><li>Log the execution of the db_checkpoint utility to the specified file in the
following format, where <i>###</i> is the process ID, and the date
is the time the utility was started.
<blockquote><pre>db_checkpoint: ### Wed Jun 15 01:23:45 EDT 1995</pre></blockquote>
This file will be removed if the db_checkpoint utility exits gracefully.</ul>
<b>-P</b><ul compact><li>Specify an environment password. Although Berkeley DB utilities overwrite
password strings as soon as possible, be aware there may be a window of
vulnerability on systems where unprivileged users can see command-line
arguments or where utilities are not able to overwrite the memory
containing the command-line arguments.</ul>
<b>-p</b><ul compact><li>Checkpoint the database at least every <b>min</b> minutes if there has
been any activity since the last checkpoint.</ul>
<b>-V</b><ul compact><li>Write the library version number to the standard output, and exit.</ul>
<b>-v</b><ul compact><li>Write the time of each checkpoint attempt to the standard output.</ul>
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<p>At least one of the <b>-1</b>, <b>-k</b>, and <b>-p</b> options
must be specified.</p>
<p>The db_checkpoint utility uses a Berkeley DB environment (as described for the
<b>-h</b> option, the environment variable <b>DB_HOME</b>, or
because the utility was run in a directory containing a Berkeley DB
environment). In order to avoid environment corruption when using a
Berkeley DB environment, db_checkpoint should always be given the chance to
detach from the environment and exit gracefully. To cause db_checkpoint
to release all environment resources and exit cleanly, send it an
interrupt signal (SIGINT).</p>
<p>The db_checkpoint utility does not attempt to create the Berkeley DB
shared memory regions if they do not already exist. The application
that creates the region should be started first, and once the region is
created, the db_checkpoint utility should be started.</p>
<p>The <a href="../api_c/txn_checkpoint.html">DB_ENV->txn_checkpoint</a> method is the underlying method used by the db_checkpoint utility.
See the db_checkpoint utility source code for an example of using <a href="../api_c/txn_checkpoint.html">DB_ENV->txn_checkpoint</a>
in a IEEE/ANSI Std 1003.1 (POSIX) environment.</p>
<p>The db_checkpoint utility exits 0 on success, and >0 if an error occurs.</p>
<br><b>Environment Variables</b>
<br>
<b>DB_HOME</b><ul compact><li>If the <b>-h</b> option is not specified and the environment variable
DB_HOME is set, it is used as the path of the database home, as described
in <a href="../api_c/env_open.html">DB_ENV->open</a>.</ul>
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