Oracle 12c New Feature – Online Partitioning.txt
作者：互联网
--//oracle 12c 支持建立分区表新特性，就是在线修改普通表为分区表。
1.环境：
SCOTT@test01p> @ ver1
PORT_STRING VERSION BANNER CON_ID
-------------------- ---------- ---------------------------------------------------------------------------- ------
IBMPC/WIN_NT64-9.1.0 12.2.0.1.0 Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production 0
SCOTT@test01p> create table tx as select rownum id ,'test' name from dual connect by level<=2e4;
Table created.
SCOTT@test01p> create unique index i_t_id on tx (id);
Index created.
SCOTT@test01p> create index i_t_name on tx (name);
Index created.
SCOTT@test01p> create index i_t_id_name on tx (id,name);
Index created.
--//分析略。
2.测试：
--//session 1,插入不提交。
SCOTT@test01p> insert into tx values (2e4+1,'aaaa');
1 row created.
--//session 2,执行如下：
alter table tx modify partition by range (id)
(PARTITION p1 VALUES LESS THAN (10000),
PARTITION p2 VALUES LESS THAN (20000),
PARTITION px VALUES LESS THAN (MAXVALUE)) ONLINE ;
--//挂起!!
--//session 1:
SCOTT@test01p> @ spid
SID SERIAL# PROCESS SERVER SPID PID P_SERIAL# C50
---------- ---------- ------------------------ --------- -------------------- ------- ---------- --------------------------------------------------
251 41873 7720:4852 DEDICATED 6316 27 4 alter system kill session '251,41873' immediate;
SCOTT@test01p> @ viewlock
SID SERIAL# USERNAME OSUSER MACHINE MODULE LOCK_TYPE MODE_HELD MODE_REQUE LOCK_ID1 LOCK_ID2 OWNER OBJECT_TYP OBJECT_NAME BLOCK LOCKWAIT
------ ---------- ---------- ---------- ---------- ------------ --------------- ---------- ---------- ---------- ---------- ------ ---------- -------------------- ----- --------------------
24 45764 SCOTT ZWS\Admini WORKGROUP\ SQL*Plus TM DML(TM) Row-X (SX) None 27765 0 SCOTT TABLE TX No 000007FF091426B8
24 45764 SCOTT ZWS\Admini WORKGROUP\ SQL*Plus TM DML(TM) Exclusive None 27775 0 SCOTT TABLE SYS_RMTAB$$_H27765 No 000007FF091426B8
24 45764 SCOTT ZWS\Admini WORKGROUP\ SQL*Plus TX Transaction None Share 589839 1387 No 000007FF091426B8
24 45764 SCOTT ZWS\Admini WORKGROUP\ SQL*Plus TM DML(TM) Exclusive None 27773 0 SCOTT TABLE SYS_JOURNAL_27765 No 000007FF091426B8
24 45764 SCOTT ZWS\Admini WORKGROUP\ SQL*Plus TX Transaction Exclusive None 262173 1470 No 000007FF091426B8
251 41873 SCOTT ZWS\Admini WORKGROUP\ SQL*Plus TX Transaction Exclusive None 589839 1387 Yes
251 41873 SCOTT ZWS\Admini WORKGROUP\ SQL*Plus TM DML(TM) Row-X (SX) None 27765 0 SCOTT TABLE TX No
7 rows selected.
--//因为session 有事务没有提交。
SCOTT@test01p> commit ;
Commit complete.
--//session 2,很快建立完成。
SCOTT@test01p> SELECT PARTITION_NAME FROM USER_TAB_PARTITIONS WHERE TABLE_NAME='TX';
PARTITION_NAME
--------------------
P1
P2
PX
SCOTT@test01p> select * from tx where id=1;
ID NAME
---------- --------------------
1 test
SCOTT@test01p> @ dpc '' ''
PLAN_TABLE_OUTPUT
-------------------------------------
SQL_ID 6sj645u5hrrbv, child number 0
-------------------------------------
An uncaught error happened in prepare_sql_statement : ORA-01403: no data found
Plan hash value: 419152296
郑州同济医院：http://jbk.39.net/yiyuanzaixian/zztjyy/
-------------------------------------------------------------------------------------------------------
| Id | Operation | Name | E-Rows |E-Bytes| Cost (%CPU)| E-Time | Pstart| Pstop |
-------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | | | 2 (100)| | | |
| 1 | PARTITION RANGE SINGLE| | 1 | 10 | 2 (0)| 00:00:01 | 1 | 1 |
|* 2 | INDEX RANGE SCAN | I_T_ID_NAME | 1 | 10 | 2 (0)| 00:00:01 | 1 | 1 |
-------------------------------------------------------------------------------------------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - SEL$1
2 - SEL$1 / TX@SEL$1
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("ID"=1)
Note
-----
- Warning: basic plan statistics not available. These are only collected when:
* hint 'gather_plan_statistics' is used for the statement or
* parameter 'statistics_level' is set to 'ALL', at session or system level
--//可以发现索引重新建立，变成了local分区索引。
--//你可以发现i_t_id_name也是local分区索引。i_t_name是global索引，大家可以自行验证结果不再贴出。
--//也就是如果建立分区表，其原来索引包含分区的键值并且在前面，建立的索引是前缀分区索引。而原来索引没有包含分区的键值，
--//建立的就是global索引。
--//我的理解这个相当于以前的在线重定义，只不过oracle封装为1个命令实现了整个过程罢了。
标签：test01p,Partitioning,12c,session,Feature,TM,SCOTT,SQL,id 来源： https://blog.51cto.com/14478010/2427424