----测试参数与parse_calls及executions的关系
----修改此参数要重启数据库
SQL> show parameter session_cached

NAME                                 TYPE
------------------------------------ --------------------------------
VALUE
------------------------------
session_cached_cursors               integer
200

---测试会话
SQL> show user
USER is "WISDOMONE"

SQL> select /*+ test */ a from t_version;

no rows selected

--管理会话
set linesize 200
col sql_text for a40
select sql_text,version_count,loads,parse_calls,invalidations from v$sqlarea where sql_text like '%select /*+ test */ a from t_version%'

SQL_TEXT                                 VERSION_COUNT      LOADS PARSE_CALLS INVALIDATIONS
---------------------------------------- ------------- ---------- ----------- -------------
select /*+ test */ a from t_version                  1          1           1             0

---测试会话,运行sql 4次
SQL> /

SQL_TEXT                                 VERSION_COUNT      LOADS PARSE_CALLS EXECUTIONS INVALIDATIONS
---------------------------------------- ------------- ---------- ----------- ---------- -------------
select /*+ test */ a from t_version                  1          1           4          4             0

小结：parse_calls与executions相同

---再看下update的的表现

---测试会话
SQL> var x number

SQL> exec :x:=20;

PL/SQL procedure successfully completed.

SQL> update t_version set a=:x;

0 rows updated.

---管理会话
SQL> select sql_text,version_count,loads,parse_calls,executions,invalidations from v$sqlarea where sql_text like '%update t_version set%';

SQL_TEXT                                 VERSION_COUNT      LOADS PARSE_CALLS EXECUTIONS INVALIDATIONS
---------------------------------------- ------------- ---------- ----------- ---------- -------------
update t_version set a=:x                            1          1           1          1             0

---测试会话
SQL> exec :x:=100;

PL/SQL procedure successfully completed.

SQL> update t_version set a=:x;

0 rows updated.

SQL> /

SQL_TEXT                                 VERSION_COUNT      LOADS PARSE_CALLS EXECUTIONS INVALIDATIONS
---------------------------------------- ------------- ---------- ----------- ---------- -------------
update t_version set a=:x                            1          2           2          2             1

小结：update sql与select sql一样的

      session_cached_cursors与parse_calls及executions无关