修改一行代码提升 Postgres 性能 100 倍
http://www.datadoghq.com/2013/08/100x-faster-postgres-performance-by-changing-1-line/
SELECT c.key,
c.x_key,
c.tags,
x.name
FROM context c
JOIN x
ON c.x_key = x.key
WHERE c.key = ANY (ARRAY[15368196, -- 11,000 other keys --)])
AND c.x_key = 1
AND c.tags @> ARRAY[E'blah'];
SELECT c.key,
c.x_key,
c.tags,
x.name
FROM context c
JOIN x
ON c.x_key = x.key
WHERE c.key = ANY (VALUES (15368196), -- 11,000 other keys --)
AND c.x_key = 1
AND c.tags @> ARRAY[E'blah'];