I suspect, without knowing for sure, that the server will preallocate the 16MB (or
whatever) and then proceed to fill it in. Such a malloc is not costly, and not risky
(unless you have thousands of threads doing the same thing at the same time).
Who cares? If GROUP_CONCAT() is what you need, then pay whatever the price is.
"If you hit a MySQL limit, you are probably mis-using MySQL."
> -----Original Message-----
> From: Paul Halliday [mailto:paul.halliday@stripped]
> Sent: Friday, January 04, 2013 5:12 AM
> To: mysql mailing list
> Subject: questions about group_concat_max_len
> Are there performance considerations if this value is set really high,
> say big enough to fit into max_allowed_packet? Does it matter?
> Paul Halliday
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe: http://lists.mysql.com/mysql