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

Personally if you havea one to many relationship and each record in table a only relates to one record in table b, I would store the table b id in table a and then do a regular join to get the data. What you currently have is a bad design that can never be truly efficient.