mysql_explain_log reads its standard input
for query log contents. It uses EXPLAIN
to
analyze SELECT
statements found in the
input. UPDATE
statements are rewritten to
SELECT
statements and also analyzed with
EXPLAIN
.
mysql_explain_log then displays a summary
of its results.
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:
Select entries from the log only for the given date.
--host=
,
host_name
-h
host_name
Connect to the MySQL server on the given host.
--password=
,
password
-p
password
The password to use when connecting to the server.
Specifying a password on the command line should be considered insecure. See Section 5.9.6, “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.
--user=
,
user_name
-u
user_name
The MySQL username to use when connecting to the server.