查看是否为分布键查询
最近更新时间: 2025-10-11 18:10:00
postgres=# explain select * from tbase_1 where f1=1;
QUERY PLAN
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Remote Fast Query Execution (cost=0.00..0.00 rows=0 width=0)
Node/s: dn001, dn002
-> Gather (cost=1000.00..7827.20 rows=1 width=14)
Workers Planned: 2
-> Parallel Seq Scan on tbase_1 (cost=0.00..6827.10 rows=1 width=14)
Filter: (f1 = 1)
(6 rows)
postgres=# explain select * from tbase_1 where f2=1;
QUERY PLAN
--------------------------------------------------------------------------------
Remote Fast Query Execution (cost=0.00..0.00 rows=0 width=0)
Node/s: dn001
-> Gather (cost=1000.00..7827.20 rows=1 width=14)
Workers Planned: 2
-> Parallel Seq Scan on tbase_1 (cost=0.00..6827.10 rows=1 width=14)
Filter: (f2 = 1)
(6 rows)上面第一个查询为非分布键查询，需要发往所有节点，这样最慢的节点决定了整个业务的速度，需要保持所有节点的响应性能一致，业务设计查询时尽可能带上分布键。