8-2-1. 머지 조인의 비효율

-- [SQL-8-2-1-a] EXPLAIN (ANALYZE,COSTS OFF) SELECT /*+ MergeJoin(t1 t2) */ t1.mbr_id ,t1.nick_nm ,t2.ord_dtm ,t2.ord_amt FROM startdbpg.ms_mbr_big t1 INNER JOIN startdbpg.tr_ord_big t2 ON (t2.mbr_id = t1.mbr_id) WHERE t2.shop_id = 'S025';