云原生数据库PieCloudDB 性能优化之路* FROM foo LEFT JOIN bar ON TRUE WHERE COALESCE(bar.c, 1) = 42; QUERY PL AN ----------------------- ---- ----- ---- - Nested Loop Left Join Filter: (COALESCE( bar.c, 1) = 42) -> Seq Scan on foo0 码力 | 26 页 | 711.44 KB | 1 年前3- PostgreSQL 查询优化器解析JOIN bar ON foo.a = bar.c WHERE COALESCE(bar.c, 1) = 42; QUERY PLAN ------------------------------------- Hash Left Join Hash Cond: (foo.a = bar.c) Filter: (COALESCE(bar.c, 1) = 42) -> Seq Scan on0 码力 | 37 页 | 851.23 KB | 1 年前3
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