... don't work very well using the MyISAM table type. Corruptions and system lock-ups are a-plenty when you have MyISAM tables with more than 1,000,000 records. The only reason that you would want to use MyISAM tables is to use the full-text searching functionality, and this feature is only marginally better than using the SQL 'like' statement.
Oh hell, my data is no more,
It all lies on the floor!
I used a cheap database,
And now I've lost some face.
MySQL is just such a chore!
If you are hosting millions of records and need any text-searching capability, then your data is probably worth more than the system itself. So go for a proper, but paid-for, RDBMS like Oracle, which also has excellent full-text searching capability.
"Don't spoil the boat for a ha'penny's worth of tar" as they say.