Looking at my favorite rss feeds today, I found this post on great MySQL Performance Blog:
…if you press CTRL-C MySQL Command Line Client will not exit but will terminate query being executed.
In other words, in previous versions of MySQL client program, if you issue a query and try to interrupt it by hitting CTRL-C, CTRL-C would actually kill MySQL client itself, but query still continue running in background! In this case the only solution to really kill that query is to find it’s ID on process list (by issuing “show full processlist” query), and then to kill it with a query like “kill 12345”, where 12345 is ID of query that you want to be killed. In other words, something like this:
mysql> select * from odm_result_keywords where keyword like '%foo%joe%';
^CAborted
bash-2.05b$ mysql -A --enable-local-infile -udinke -ppass mydb
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1512 to server version: 4.1.18-log
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> show full processlist;
+------+-------+----------------------------+-------------------+---------+------+--------------+--------------------------------------------------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+------+-------+----------------------------+-------------------+---------+------+--------------+--------------------------------------------------------------------+
| 1486 | dinke | localhost | mydb | Query | 3 | Sending data | select * from odm_result_keywords where keyword like '%foo%joe.cl' |
+------+-------+----------------------------+-------------------+---------+------+--------------+--------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql> kill 1486;
mysql>
Thanks to changes in MySQL client program, all you have to do now is to hit CTRL-C, and query will be stopped immediately:
mysql> select domain from odm_result_keywords_de where whois_status is null and domain like '%.%.%';
Query aborted by Ctrl+C
ERROR 1317 (70100): Query execution was interrupted
mysql>
For more information about this feature (as well as other changes in MySQL 5.0.25) please follow this link.