Hi again!
I was scanning through some old mails to check if we had some unsolved
things before doing a new relase and stumbled across the following mail:
>>>>> "Jochen" == Jochen Wiedmann <joe@stripped> writes:
Jochen> Hi,
Jochen> I have a table similar to the following:
Jochen> start INTEGER
Jochen> end INTEGER
Jochen> where start <= end are arbitrary ranges.
Jochen> Does anyone have recommendations of how to choose an index
Jochen> that allows me to select those records that include a certain
Jochen> number? In other words, I like to optimize the query
Jochen> SELECT * FROM mytable WHERE start <= mynumber AND
Jochen> end >= mynumber;
The only 'easy' thing I can think of is if you know how big the biggest
start-end range is. In this case you can do:
SELECT * FROM mytable WHERE start between my_number-max_range and mynumber AND
end between mynumber and my_number+max_range;
This will let MySQL use a much smaller set of rows to examine for the
range.
Regards,
Monty
PS: Sorry for the delay, hope late was better than never.
