Bug #29054 log-output=TABLE will still log headers to the log FILE.
Submitted: 12 Jun 2007 16:52 Modified: 13 Jun 2007 4:20
Reporter: Tobias Asplund Email Updates:
Status: Not a Bug Impact on me:
None 
Category:MySQL Server: Logging Severity:S3 (Non-critical)
Version:5.1.19 OS:MacOS
Assigned to: CPU Architecture:Any

[12 Jun 2007 16:52] Tobias Asplund 
Description:
Even when logging to a file is disabled, the slow query log will write it's header information on server startup to the log file.

How to repeat:
start a server up with:

--log-output=TABLE
--log-slow-queries=/path/file

check the /path/file, it'll now have a header.
[12 Jun 2007 17:05] Paul DuBois 
As documented.

"The --log[=file_name] option, if given, enables logging to the general query log for the selected log destinations. Similarly, the --log-slow-queries[=file_name] option, if given, enables logging to the slow query log for the selected destinations. If you specify either option, the server opens the corresponding log file and writes startup messages to it. However, logging of queries to the file does not occur unless the FILE log destination is selected."

http://dev.mysql.com/doc/refman/5.1/en/log-tables.html
[13 Jun 2007 4:20] Valeriy Kravchuk 
So, this is not a bug, but intended(?) and documented behaviour.