实验准备：

hr@ORCL> drop table t purge;

Table dropped.

hr@ORCL> create table t (code number);

Table created.

hr@ORCL> create table t_audit (code number,ins_date date);

Table created.

hr@ORCL> create or replace trigger tri_audit_t
  2      before insert     
  3      on t
  4      for each row
  5      begin
  6        insert into t_audit values(:new.code,sysdate);
  7      end;
  8      /

hr@ORCL> alter session set sql_trace=true;

Session altered.

hr@ORCL> alter session set tracefile_identifier=\'linwaterbin_null\';  --session_1

Session altered.

hr@ORCL> alter session set tracefile_identifier=\'linwaterbin\';  --session_2

Session altered.

hr@ORCL> set feedback off

hr@ORCL> ed
Wrote file afiedt.buf

  1  SELECT s.SID,VALUE,NAME
  2    FROM v$sesstat s,v$statname n WHERE s.sid = 139
  3*        AND s.STATISTIC#=n.STATISTIC# AND n.NAME IN( \'parse count (total)\',\'parse count (hard)\')
hr@ORCL> /

       SID      VALUE NAME
---------- ---------- ----------------------------------------------------------------
       139        304 parse count (total)
       139         99 parse count (hard)

hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> ed
Wrote file afiedt.buf

  1  SELECT s.SID,VALUE,NAME
  2    FROM v$sesstat s,v$statname n WHERE s.sid = 139
  3*        AND s.STATISTIC#=n.STATISTIC# AND n.NAME IN( \'parse count (total)\',\'parse count (hard)\')
hr@ORCL> /

       SID      VALUE NAME
---------- ---------- ----------------------------------------------------------------
       139        344 parse count (total)
       139        101 parse count (hard)

       session_2实验：

hr@ORCL> ed
Wrote file afiedt.buf

  1  create or replace procedure pro_t_audit(p_code number)
  2  is
  3  begin
  4   insert into t_audit values(p_code,sysdate);
  5* end;
hr@ORCL> /

Procedure created.

hr@ORCL> ed
Wrote file afiedt.buf

  1  create or replace trigger tri_audit_t
  2  before insert
  3  on t
  4  for each row
  5* call pro_t_audit(:new.code)
hr@ORCL> /

Trigger created.

hr@ORCL> ed
Wrote file afiedt.buf

  1  SELECT s.SID,VALUE,NAME
  2    FROM v$sesstat s,v$statname n WHERE s.sid = 159
  3*        AND s.STATISTIC#=n.STATISTIC# AND n.NAME IN( \'parse count (total)\',\'parse count (hard)\')
hr@ORCL> /

       SID      VALUE NAME
---------- ---------- ----------------------------------------------------------------
       159        414 parse count (total)
       159        176 parse count (hard)

hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> insert into t values(1);
hr@ORCL> ed
Wrote file afiedt.buf

  1  SELECT s.SID,VALUE,NAME
  2    FROM v$sesstat s,v$statname n WHERE s.sid = 159
  3*        AND s.STATISTIC#=n.STATISTIC# AND n.NAME IN( \'parse count (total)\',\'parse count (hard)\')
hr@ORCL> /

       SID      VALUE NAME
---------- ---------- ----------------------------------------------------------------
       159        447 parse count (total)
       159        178 parse count (hard)

INSERT INTO T_AUDIT 
VALUES
(:B1 ,SYSDATE)


call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse       10      0.00       0.00          0          0          0           0
Execute     10      0.01       0.04          4         10         34          10
Fetch        0      0.00       0.00          0          0          0           0
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total       20      0.01       0.04          4         10         34          10 
  

INSERT INTO T_AUDIT 
VALUES
(:B1 ,SYSDATE)


call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse        1      0.00       0.00          0          0          0           0
Execute     10      0.00       0.04          4          1         14          10
Fetch        0      0.00       0.00          0          0          0           0
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total       11      0.00       0.04          4          1         14          10