Re: Most efficient way to insert without duplicates

> INSERT INTO persona_followers(service_id, follower_id, valid_at)
> SELECT service_id, follower_id, NOW()
> FROM (SELECT DISTINCT service_id, follower_id FROM import) AS import
> WHERE NOT EXISTS(SELECT * FROM persona_followers WHERE import.service_id
> = persona_followers.service_id AND import.follower_id =
> persona_followers.follower_id);
>
>
I'm wondering if you have an unneeded level of nesting. (I don't know if it
would make any difference, but it might).

INSERT INTO persona_followers(service_id, follower_id, valid_at)
SELECT DISTINCT service_id, follower_id, now()
FROM import
WHERE NOT EXISTS(SELECT * FROM persona_followers WHERE import.service_id =
persona_followers.service_id AND import.follower_id =
persona_followers.follower_id);