hash join

最近更新时间: 2025-02-18 16:02:00

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postgres=# explain select * from t3,t4 where t3.f1=t4.f1;
                               QUERY PLAN                               
------------------------------------------------------------------------
 Remote Fast Query Execution  (cost=0.00..0.00 rows=0 width=0)
   Node/s: dn001, dn002
   ->  Hash Join  (cost=76.62..209.52 rows=2561 width=16)
         Hash Cond: (t4.f1 = t3.f1)
         ->  Seq Scan on t4  (cost=0.00..88.39 rows=5039 width=8)
         ->  Hash  (cost=44.61..44.61 rows=2561 width=8)
               ->  Seq Scan on t3  (cost=0.00..44.61 rows=2561 width=8)
(7 rows)