Oracle Arraysize设置对于逻辑读的影响实例分析

-- 查看当前的Arraysize
SQL> show arraysize
arraysize 15

SQL> set autotrace traceonly statistics
SQL> select * from dba_objects;

72457 rows selected.

Statistics
----------------------------------------------------------
     0 recursive calls
     0 db block gets
    7675 consistent gets
     5 physical reads
     0 redo size
  3463453 bytes sent via SQL*Net to client
   53549 bytes received via SQL*Net from client
    4832 SQL*Net roundtrips to/from client
     0 sorts (memory)
     0 sorts (disk)
   72457 rows processed

-- 设置Arraysize为50
SQL> set arraysize 50
SQL> /

72457 rows selected.

Statistics
----------------------------------------------------------
     15 recursive calls
     0 db block gets
    3618 consistent gets
     0 physical reads
     0 redo size
  3034066 bytes sent via SQL*Net to client
   16358 bytes received via SQL*Net from client
    1451 SQL*Net roundtrips to/from client
     0 sorts (memory)
     0 sorts (disk)
   72457 rows processed