Re: How to improve query performance in expression related order by?

[Rick James]

To assist in analyzing slow SELECTs, please provide
* SHOW CREATE TABLE tbl\G <-- Engine type? Indexes?
* SHOW TABLE STATUS LIKE 'tbl'\G <-- row size
* EXPLAIN SELECT ...\G <-- what it decided to do
and surround them with [ code ] and [ / code ]

Is the query optimizer smart enough to use INDEX(lat) on expressions like
(lat - 12.34) < 0.1 (lat-12.34) > -0.1
instead of a simple range like
lat BETWEEN 12.34 - 0.1 AND 12.34 + 0.1

Do you have an ID for each row?