> I have two tables. One table is 13 million rows the other is about
> 250,000. I am trying to join the two to find users. The tables are not
> indexed and I know that will effect the speed, but the join never
> completes. I let it run for about 10 hours and the process was stuck in
> the "sending" state, which I don't really understand. What is taking so
> long? The join size should be no greater than 250,000 which is the size
> of the second table. Yes???
> I am using the default join_buffer size, which seems to low. Might this
> be the problem?
Well, running a join on tables without indexes is like running a simple
select on a table that is the cartesian product of both tables.
In your case, you are trying to run a select on a table with:
13million x 250,000 = 3,250,000,000,000 rows !
I am afraid that you won't get any result soon, even with a big join