This might be a bit like asking how long a length of string is, but the stats are:

* Intel dual core 4GB RAM
* Table with 8million rows, ~ 20 columns, mostly varchars with an auto\_increment primary id
* Query is: ALTER TABLE my\_table ADD INDEX `my_index` (my\_column);
* my\_column is varchar(200)
* Storage is MyISAM

Order of magnitude, should it be 1 minute, 10 minutes, 100 minutes?

Thanks

**Edit:** OK it took 2 hours 37 minutes, compared to 0 hours 33 mins on a lesser spec machine, with essentially identical set ups. I've no idea why it took so much longer. The only possibility is that the prod machine HD is 85% full, with 100GB free. Should be enough, but i guess it depends on how that free space is distributed.