Doing a select on a large table

[Kris Peeters]

I'm having troubles doing an ordinary select on a large MyISAM table (26 milion records).

I have to walk through the entire table and return the next thousand lines each time, so I'm not using a WHERE clause. I just adjust the LIMIT parameters in every step. I wrote a shell script for this, and it works fine.

When I select the first couple of thousand lines, mysql returned them in no time. But now, I'm selecting from near the end of the table, and it takes 2000 seconds before I get results.

I performed an EXPLAIN on these queries, and because I'm not using a WHERE clause, MySQL doesn't use any keys. Does this mean it has to iterate over the first 20 milion records, just to get the 20 000 001st?

Has anybody got an idea how I can boost up the speed of those queries?

Thanks a lot !!