The results may assist you in determining which queries result in table scans and where it would be beneficial to add indexes to your tables.
Invoke mysql_explain_log like this, where log_file contains all or part of a MySQL query log:
shell> mysql_explain_log [options] < log_file
mysql_explain_log understands the following options:
Display a help message and exit.
Select entries from the log only for the given date.
Connect to the MySQL server on the given host.
The password to use when connecting to the server.
Specifying a password on the command line should be considered insecure. See Section 5.6, "Keeping Your Password Secure".
Enable error output.
For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.
The MySQL username to use when connecting to the server.
Copyright 2007-2008 MySQL AB
This documentation is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License.
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You should have received a copy of the GNU General Public License along with the program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see http://www.gnu.org/licenses/.