Re: Nested query performance issue

(This is related to an earlier post on -sql.)

I'm querying for the N high scores for each game, with two tables:
scores and games.

CREATE TABLE game (id SERIAL NOT NULL PRIMARY KEY);
CREATE TABLE score (id SERIAL NOT NULL PRIMARY KEY, score REAL,
game_id INTEGER REFERENCES game (id));
-- test data: 1000 games, 100000 scores
INSERT INTO game (id) select generate_series(1,1000);
INSERT INTO score (game_id, score) select game.id, random() from game,
generate_series(1,100);
CREATE INDEX score_idx1 ON score (game_id, score desc);
ANALYZE;