Optimize SQL that uses between clause

Question

Consider the following 2 tables:

Table A:
id
event_time

Table B
id
start_time
end_time

Every record in table A is mapped to exactly 1 reco

Answer 1

You may want to try something like this

Select A.ID,
(SELECT B.ID FROM B
WHERE A.EventTime BETWEEN B.start_time AND B.end_time LIMIT 1) AS B_ID
FROM A

If you have an index on the Start_Time,End_Time fields for B, then this should work quite well.