目前,我有以下幾點: User (id, fname, lname, deleted_at, guest)
我可以像這樣通過他們fname初始查詢用戶的列表: User Load (9.6ms) SELECT "users".* FROM "users" WHERE (users.deleted_at IS NULL) AND (lower(left(fname, 1)) = 's') ORD
我給這個查詢PostgreSQL的9.2優化: SELECT C.name, COUNT(DISTINCT I.id) AS NumItems, COUNT(B.id)
FROM Categories C INNER JOIN Items I ON(C.id = I.category)
INNER JOIN Bids B ON (I.id = B.item_id)
GROUP