Re: Slow select with sub queries

[Tom Clark]

Thank you both, very much. If I understand the suggestion correctly, rather than unnecessarily search through the "Coordinates" table for each row of the "Main" table, this JOIN only searches through rows in the "Coordinates" table where the keys match... Wish I'd thought of that.

The suggestion works very well, by the way. Query took 0.0442 seconds, faster by a factor of 633+. Awesome.

Would either of you (or anyone) care to explain the results of the EXPLAIN SELECT that I included? In particular, I don't understand the NULL values in columns "possible_keys" and "key", and the entries in the "Extra" column.

Thanks again,
Tom



Edited 1 time(s). Last edit at 12/01/2010 02:26PM by Tom Clark.