MySQL
MySQL
... without destroying the database.
... 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.
A quick and dirty way of stripping duplicate records out of a MySQL table!, if your table has no indexes or constraints.