oracle 11g禁用和强制direct path read

How To Force Direct Path Read for SQL Statements (Doc ID 2426051.1)

Exadata Smartscan Is Not Being Used On Insert As Select (Doc ID 1348116.1)

--alter system set event='10949 TRACE NAME CONTEXT FOREVER, level 1' scope=spfile; 
SQL> alter system set "_serial_direct_read"=false scope=both sid='*'; 
SQL> SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ
  FROM SYS.x$ksppi x, SYS.x$ksppcv y
 where x.indx = y.indx
   AND (x.ksppinm = '_small_table_threshold' or
       x.ksppinm = '_serial_direct_read');

https://www.cnblogs.com/zhjh256/p/9506247.html