8-1-7. 무조건 작은 집합을 드라이빙 할 것인가?

-- [SQL-8-1-7-a]

SELECT  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 (t1.mbr_id =  t2.mbr_id) 
WHERE   t1.mbr_gd = 'PLAT' 
AND     t2.ord_dtm >= '2023-01-01'::date
AND     t2.ord_dtm <  '2025-01-01'::date;
SQL
복사

-- [SQL-8-1-7-b]: NestLoop 힌트를 추가하여 [SQL-8-1-7-a]를 실행

EXPLAIN (ANALYZE,COSTS OFF)
SELECT  /*+ NestLoop(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 (t1.mbr_id =  t2.mbr_id) 
WHERE   t1.mbr_gd = 'PLAT' 
AND     t2.ord_dtm >= '2023-01-01'::date
AND     t2.ord_dtm <  '2025-01-01'::date;
SQL
복사

-- [SQL-8-1-7-c]: [SQL-8-1-7-a]에 NestLoop와 NoMemoize 힌트를 추가

EXPLAIN (ANALYZE,COSTS OFF)
SELECT  /*+ NestLoop(t1 t2) NoMemoize(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 (t1.mbr_id =  t2.mbr_id) 
WHERE   t1.mbr_gd = 'PLAT' 
AND     t2.ord_dtm >= '2023-01-01'::date
AND     t2.ord_dtm <  '2025-01-01'::date;
SQL
복사