[20181105]再论12c set feedback only.txt

  时间:2018-11-06
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[20181105]再论12c set feedback only.txt

--//前一阵子的测试,链接:http://blog.itpub.net/267265/viewspace-2216290/
--//12CR2 ,增强了set FEEDBACK功能,加入only选项可以禁止输出信息显示,仅仅显示返回几行,有利于dba集中精力调试
--//sql语句,18c还增加返回执行语句的sql_id的功能,简单测试.

--//我一直以为这种功能是针对特定版本的比如仅仅对12c有效,实际上如果你使用12c的客户端连接11g,执行set feedback only应该不支持.
--//通过测试说明问题.

1.环境:
d:\temp>sqlplus scott/book@78
SQL*Plus: Release 12.2.0.1.0 Production on 星期一 11月 5 10:47:35 2018
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Copyright (c) 1982, 2016, Oracle.  All rights reserved.
连接到:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SCOTT@78> @ ver1
PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

--//我刚刚在办法环境重新安装12cR2版本.使用sqlplus连接11g.

SCOTT@78> set feedback only
SCOTT@78> select * from emp;
     EMPNO ENAME      JOB              MGR HIREDATE                   SAL       COMM     DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------

已选择 14 行。
--//没有多余的显示.

SCOTT@78> set feedback 6
SCOTT@78> @ dpc '' ''
PLAN_TABLE_OUTPUT
-------------------------------------
SQL_ID  a2dk8bdn0ujx7, child number 0
-------------------------------------
select * from emp
Plan hash value: 3956160932
---------------------------------------------------------------------------
| Id  | Operation         | Name | E-Rows |E-Bytes| Cost (%CPU)| E-Time   |
---------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |      |        |       |     3 (100)|          |
|   1 |  TABLE ACCESS FULL| EMP  |     14 |   532 |     3   (0)| 00:00:01 |
---------------------------------------------------------------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
   1 - SEL$1 / EMP@SEL$1

2.补充测试连接的http://blog.itpub.net/267265/viewspace-2216326/特性是否有效:
SCOTT@78> set history 10
SCOTT@78> select sysdate from dual ;
SYSDATE
-------------------
2018-11-05 10:51:00

SCOTT@78> select user from dual ;
USER
------------------------------
SCOTT

SCOTT@78> history
  1  select sysdate from dual ;
  2  select user from dual ;

--//可以发现一样有效.

SCOTT@78> variable b number = 20;
SCOTT@78> select * from dept where deptno = :b ;
    DEPTNO DNAME          LOC
---------- -------------- -------------
        20 RESEARCH       DALLAS

--//这样定义变量也没有问题.

3.最后测试Statement caching:
--//Statement caching有点像软软解析.

SCOTT@78> @ spid
       SID    SERIAL# PROCESS                  SERVER    SPID       PID  P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- ----------------------------------------------
        41          7 5512:516                 DEDICATED 62921       27          3 alter system kill session '41,7' immediate;
variable b number = 20;
Select * from dept where deptno = :b ;
Select * from dept where deptno = :b ;

--//通过查询执行计划,确定sql_id=2b073tss4h1f3.

SCOTT@78> select sql_id,executions,parse_calls,sql_text from v$sql where sql_id='2b073tss4h1f3';
SQL_ID        EXECUTIONS PARSE_CALLS SQL_TEXT
------------- ---------- ----------- ------------------------------------------------------------
2b073tss4h1f3          2           2 Select * from dept where deptno = :b

--//执行2次,分析2次.
--//如果采用Statement caching
--//sesson 1:

set statementcache 100
variable c number = 10;
select * from dept where deptno = :c ;
select * from dept where deptno = :c ;
select sysdate from dual;
--//通过查询执行计划,确定sql_id='abzxwsyzmsu8h',另外打开会话:

--//sesson 2:
SYS@book> select sql_id,executions,parse_calls,sql_text from v$sql where sql_id='abzxwsyzmsu8h';
SQL_ID        EXECUTIONS PARSE_CALLS SQL_TEXT
------------- ---------- ----------- ------------------------------------------------------------
abzxwsyzmsu8h          2           1 select * from dept where deptno = :c
--//执行2次,分析1次.

SYS@book> @ sharepool/shp4 abzxwsyzmsu8h 0
TEXT           KGLHDADR         KGLHDPAR         C40                                        KGLHDLMD   KGLHDPMD   KGLHDIVC KGLOBHD0         KGLOBHD6           KGLOBHS0   KGLOBHS6   KGLOBT16   N0_6_16        N20   KGLNAHSH KGLOBT03        KGLOBT09
-------------- ---------------- ---------------- ---------------------------------------- ---------- ---------- ---------- ---------------- ---------------- ---------- ---------- ---------- --------- ---------- ---------- ------------- ----------
子游标句柄地址 000000007E344808 000000007E0F7020 select * from dept where deptno = :c              1          0          0 000000007E373578 000000007C5D06C8       8600      12144       3086     23830      23830 3208407312 abzxwsyzmsu8h          0
父游标句柄地址 000000007E0F7020 000000007E0F7020 select * from dept where deptno = :c              1          0          0 000000007E33C8A8 00                     4720          0          0      4720       4720 3208407312 abzxwsyzmsu8h      65535

--//KGLHDLMD=1.session 1最后执行的是select sysdate from dual;

SYS@book> select * from v$open_cursor where sql_id='abzxwsyzmsu8h';
SADDR            SID USER_NAME ADDRESS          HASH_VALUE SQL_ID        SQL_TEXT                             LAST_SQL_ACTIVE_TIM SQL_EXEC_ID CURSOR_TYPE
---------------- --- --------- ---------------- ---------- ------------- ------------------------------------ ------------------- ----------- -----------
000000008631DDF0  41 SCOTT     000000007E0F7020 3208407312 abzxwsyzmsu8h select * from dept where deptno = :c                                 OPEN
--//可以发现光标状态已经是open,仅仅执行2次.

--//session 1:
SCOTT@78> variable c number = 30;
SCOTT@78> select * from dept where deptno = :c ;
    DEPTNO DNAME          LOC
---------- -------------- -------------
        30 SALES          CHICAGO

SCOTT@book> select sql_id,executions,parse_calls,sql_text from v$sql where sql_id='abzxwsyzmsu8h';
SQL_ID        EXECUTIONS PARSE_CALLS SQL_TEXT
------------- ---------- ----------- ------------------------------------------------------------
abzxwsyzmsu8h          3           1 select * from dept where deptno = :c
--//执行3次,分析1次.

4.支持CSV数据格式显示:
SCOTT@78> set markup csv on
SCOTT@78> select * from emp ;
"EMPNO","ENAME","JOB","MGR","HIREDATE","SAL","COMM","DEPTNO"
7369,"SMITH","CLERK",7902,"1980-12-17 00:00:00",800,,20
7499,"ALLEN","SALESMAN",7698,"1981-02-20 00:00:00",1600,300,30
7521,"WARD","SALESMAN",7698,"1981-02-22 00:00:00",1250,500,30
7566,"JONES","MANAGER",7839,"1981-04-02 00:00:00",2975,,20
7654,"MARTIN","SALESMAN",7698,"1981-09-28 00:00:00",1250,1400,30
7698,"BLAKE","MANAGER",7839,"1981-05-01 00:00:00",2850,,30
7782,"CLARK","MANAGER",7839,"1981-06-09 00:00:00",2450,,10
7788,"SCOTT","ANALYST",7566,"1987-04-19 00:00:00",3000,,20
7839,"KING","PRESIDENT",,"1981-11-17 00:00:00",5000,,10
7844,"TURNER","SALESMAN",7698,"1981-09-08 00:00:00",1500,0,30
7876,"ADAMS","CLERK",7788,"1987-05-23 00:00:00",1100,,20
7900,"JAMES","CLERK",7698,"1981-12-03 00:00:00",950,,30
7902,"FORD","ANALYST",7566,"1981-12-03 00:00:00",3000,,20
7934,"MILLER","CLERK",7782,"1982-01-23 00:00:00",1300,,10
已选择 14 行。

--//ok.剩下的不在测试了,剩下大家自行测试.

set markup csv on delimiter '|'
select * from dept;

set markup csv on delimiter '|' quote off
select * from dept;

set markup csv off
select * from dept;

5.看来自己以前感觉错误,sqlplus的特性与oracle版本无关,你只要安装12cR2版本的client端,就可以使用新版本的sqlplus的特性.
  也说明一点,做事情不能评感觉,还是以测试为准,当然理论的理解也很重要.
 

原文地址:http://www.manongjc.com/article/17440.html