merge join

最近更新时间: 2025-02-18 16:02:00

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postgres=# explain select * from t1,t2 where t1.f1=t2.f1;
                                        QUERY PLAN                                        
------------------------------------------------------------------------------------------
 Remote Fast Query Execution  (cost=0.00..0.00 rows=0 width=0)
   Node/s: dn001, dn002
   ->  Merge Join  (cost=1.91..380.65 rows=5039 width=45)
         Merge Cond: (t1.f1 = t2.f1)
         ->  Index Scan using tf_f1_idx on t1  (cost=0.42..15956.88 rows=500564 width=37)
         ->  Index Scan using t2_f1_idx on t2  (cost=0.28..146.87 rows=5039 width=8)
(6 rows)