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 126.96.36.199, "End-User Guidelines for Password Security".
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 user name to use when connecting to the server.
Copyright 2007-2008 MySQL AB, 2009 Sun Microsystems, Inc.
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