MySQL Join Optimisation - 2 hours, for what should take seconds!!
I have been trying to optimise a MySQL script, which for some reason is taking over 2 hours to run! I've been unable to figure out why the script takes so long to run, so any help and tips for identifying the cause of the problem would be appreciated.
The script is very simple, essentially:
SELECT x.*, y.field1, y.field2, y.field3
FROM table1 x
LEFT JOIN table2 y
on x.date = y.date and x.id = y.id and x.id2 = y.id2
Both tables are approximately 90k rows.