Hello, I'm running MySQL 5.1.46 on Linux. It works fine. I have a larger database that has one 700MB table. Its slow because of the way to do my selects. I'm not very good at optimizing things so I don't know how to improve it.

For example when I do:
select distinct channel_num from Track where account_num = '123'

I get this for "show processlist" and of course it takes like 500 seconds:
Copying to tmp table

How can I improve this?

channel_num along with some text fields are pretty much what makes up the table.

what indexes are defined on the table?

Theres a bunch of indexes, but I don't know if they're helping or hurting the problem. For example theres a field account_num, video_num, channel_num and some dates which all have a unique index. Theres 11 indexes on this table. Is that too much?

for a SELECT, no

please do a SHOW CREATE TABLE for this table

The table is called Track. This is it below.

Track | CREATE TABLE `Track` (
`track_num` int(8) NOT NULL AUTO_INCREMENT,
`track_type` varchar(32) DEFAULT NULL,
`account_num` int(8) DEFAULT NULL,
`video_num` int(8) DEFAULT NULL,
`channel_num` int(8) DEFAULT NULL,
`channel_name` varchar(255) DEFAULT NULL,
`channel_name_internal_label` varchar(255) DEFAULT NULL,
`video_title` varchar(254) DEFAULT NULL,
`video_name_internal_label` varchar(255) DEFAULT NULL,
`video_date` date DEFAULT NULL,
`full_datetime` varchar(64) DEFAULT NULL,
`ip` varchar(32) DEFAULT NULL,
`video_filename` varchar(254) DEFAULT NULL,
`referrer` varchar(254) DEFAULT NULL,
`embed_autostart` int(1) DEFAULT NULL,
`timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`track_num`),
KEY `key_account_video_num` (`account_num`,`video_num`),
KEY `key_account_num` (`account_num`),
KEY `key_video_num` (`video_num`),
KEY `key_account_num_channel` (`account_num`,`channel_name`),
KEY `key_account_num_video_date` (`account_num`,`video_date`),
KEY `key_account_num_type` (`account_num`,`track_type`),
KEY `key_channel_num` (`channel_num`)
) ENGINE=MyISAM AUTO_INCREMENT=3947519 DEFAULT CHARSET=latin1

see the index called key_account_num_channel?

that would really work well for this query if it was indeed an index on account_num and channel_num

unfortunately it's on account_num and channel_name

so you will have to add yet another index --

ALTER TABLE
ADD INDEX key_account_num_channel_num ( account_num , channel_num )

p.s. some of your indexes are redundant, but that only hurts INSERTs, UPDATEs, and DELETEs