5-2-6. 복합 인덱스의 선두 조건 누락

-- [SQL-5-2-6-a] EXPLAIN (ANALYZE,BUFFERS,COSTS OFF) SELECT /*+ IndexScan(t1 tr_ord_big_x03) */ t1.* FROM startdbpg.tr_ord_big t1 WHERE t1.mbr_id = 'M00031';

-- [SQL-5-2-6-b] SELECT t1.relname ,t1.relpages block_cnt FROM pg_class t1 WHERE t1.oid = 'startdbpg.tr_ord_big_x03'::regclass;