Best way to join on a range?

Question

I think this may be a common problem that may not have an answer for every tool. Right now we are trying to use amazons Redshift. The only problem we have now is we are tryi

Answer 1

Beginning with PostgreSQL 9.2 you could use one of the new range types,int4range or int8range.

CREATE TABLE city (
  city_id serial PRIMARY KEY 
 ,ip_range int4range
 ,city text
 ,zip  text
);

Then your query could simply be:

SELECT c.zip
FROM   city_ip 
WHERE  $intip <@ i.ip_range;

<@ .. "element is contained by"

To make this fast for a big table use a GiST index:

CREATE INDEX city_ip_range_idx ON city USING gist (ip_range);

But I doubt Amazon Redshift is up to date. We had other people with problems recently:
Using sql function generate_series() in redshift

Answer 2

Assuming the range is contained within TableA, and the ID is in TableB, the following query should work with SQL

SELECT TableA.*, TableB.*
FROM TableA JOIN TableB 
ON TableA.StartIP <= TableB.ID AND TableB.ID <= TableA.EndIP

Answer 3

Try using between, listing the table with the target value second:

select *
from table1 t1
join table2 t2
  on t2.ip between t1.startip and t1.endip

And make sure there's an index on table2.ip.

It should perform pretty well.