PostgreSQL query runs faster with index scan, but engine chooses hash join

Question

The query:

SELECT \"replays_game\".*
FROM \"replays_game\"
INNER JOIN
 \"replays_playeringame\" ON \"replays_game\".\"id\" = \"replays_playeringame\".\"game_         


        

Answer 1

You might get a better execution plan using a multiple column (player_id, game_id) index on the replays_playeringame table. This avoids having to use a random page seek to look up the game id(s) for the player id.