As I have a large database, I need to do some form of data indexing.

The problem is I need to search the database again with a value that fits within a range. For eg.

a = [12 23 16 31 42] may be stored under one particular index (<50). I know need to search for a value within a range of the values in 'a'.

[10-14, 21-25, 14-18, 29-33, 40-44]

If I have a value 30, it should match the fourth value in 'a'.

What would be the best data indexing method to do this?

Any help would be appreciated. Thanks.