该计划看起来正常吗？ INDEX RANGE SCAN MTL_ITEM_CATEGORIES_N4正在读取769549行，然后从表中读取了相同数量的行。这正常吗？
0 0 0 HASH JOIN (cr=0 pr=0 pw=0 time=19 us cost=181693 size=1530 card=15)
1146877 1146877 1146877 NESTED LOOPS (cr=3545011 pr=167590 pw=0 time=3850324669 us cost=181689 size=1005 card=15)
1146878 1146878 1146878 NESTED LOOPS (cr=1888277 pr=14528 pw=0 time=1674644783 us cost=181689 size=1005 card=1255314)
769549 769549 769549 TABLE ACCESS BY INDEX ROWID BATCHED MTL_ITEM_CATEGORIES (cr=51305 pr=7253 pw=0 time=56155426 us cost=6029 size=607410 card=40494)
769549 769549 769549 INDEX RANGE SCAN MTL_ITEM_CATEGORIES_N4 (cr=2441 pr=809 pw=0 time=8372404 us cost=190 size=0 card=40494)(object id 24699978)
1146878 1146878 1146878 INDEX RANGE SCAN MTL_MATERIAL_TRANSACTIONS_N1 (cr=1836972 pr=7275 pw=0 time=323445690 us cost=3 size=0 card=31)(object id 1215228)
1146877 1146877 1146877 TABLE ACCESS BY INDEX ROWID MTL_MATERIAL_TRANSACTIONS (cr=1656734 pr=153062 pw=0 time=2130656126 us cost=30 size=52 card=1)
0 0 0 TABLE ACCESS FULL MTL_TRANSACTION_TYPES (cr=0 pr=0 pw=0 time=0 us cost=4 size=4095 card=117)
0 0 0 TABLE ACCESS BY INDEX ROWID BATCHED CST_AE_HEADERS (cr=0 pr=0 pw=0 time=0 us cost=3 size=30 card=1)