Hello,
The problem I'm working on is to order table scans so that one scan can
insert filters into the another. It seems like it should be a common
problem so I'm sure I'm missing some context. Taking a concrete example,
imagine two tables Users and Movies with the following schema
User {
id: long
name: String
}
Movie {
id : long
name: String
director_user_id : long
}
movie.director_user_id is a foreign key to user.id
So for this query,
SELECT m.name as movieName, u.name as directorName
FROM Movie as m
JOIN User as u
ON m.director_user_id = u.id
WHERE m.id = 1;
Ideally, I'd like the table scan of Movie to go first, retrieve the
director_user_id and then inject the value(s) as a filter into the scan for
User (instead of doing a full table scan on User).
My question is
- Does Calcite provide an inbuilt way to do this?
- If not, could you help me by pointing to any implementations that do this
so that I can learn from them and apply it to my use case?
I'v tried to search in stack overflow and the dev archives but haven't been
able to find something that can help. Any guidance is much appreciated !
Cheers,
Gopal
