12CR2 “alter table move”命令導致資料損壞？
摘要：
在對具有以下特徵的表發出“alter table move”命令時，會發生資料損壞的情況：
1、該表包含使用者定義的型別，該型別宣告為NOT INSTANTIABLE和NOT FINAL。
2、至少有三個類繼承自此使用者定義的型別。
示例如下：
...
在對具有以下特徵的表發出“alter table move”命令時，會發生資料損壞的情況：
1、該表包含使用者定義的型別，該型別宣告為NOT INSTANTIABLE和NOT FINAL。
2、至少有三個類繼承自此使用者定義的型別。
示例如下：
1.建立type
首先建立基本的type。必須是NOT INSTANTIABLE NOT FINAL型別的.
CREATE OR REPLACE TYPE ty_parent AS OBJECT( n1_parent NUMBER ) NOT INSTANTIABLE NOT FINAL ;
2.三個類繼承自此使用者定義的型別。
CREATE OR REPLACE TYPE ty_child_1 UNDER ty_parent( VALUE varchar2(300) ) FINAL ; CREATE OR REPLACE TYPE ty_child_2 UNDER ty_parent( VALUE TIMESTAMP ) FINAL ; CREATE OR REPLACE TYPE ty_child_3 UNDER ty_parent( VALUE number ) FINAL ;
3.建立表，宣告為ty_parent型別
create table t1 (ty1 ty_parent , n1 number) ;
4.插入資料
insert into t1 values ( ty_child_1( 1, 'AAAAAAAAAAAAAAAA' ) , 1 ) ; commit;
5.DUMP定義類中的資料，這裡可以看到因為插入的是字元型別，儲存在ty_child_1當中
SQL> select 2 dump(TREAT(ty1 AS ty_child_1).VALUE,16), 3 dump(TREAT(ty1 AS ty_child_2).VALUE,16), 4 dump(TREAT(ty1 AS ty_child_3).VALUE,16) 5 from t1 ; DUMP(TREAT(TY1ASTY_CHILD_1).VALUE,16) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- DUMP(TREAT(TY1ASTY_CHILD_2).VALUE,16) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- DUMP(TREAT(TY1ASTY_CHILD_3).VALUE,16) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Typ=1 Len=16: 41,41,41,41,41,41,41,41,41,41,41,41,41,41,41,41 NULL NULL
6.使用alter table move移動表
SQL> alter table t1 move; Table altered.
7.再次DUMP定義類中的資料，這裡可以看到資料移動到了ty_child_2當中。即使兩列都有不同的資料型別。ty_child_1是字元型，ty_child_2是時間型別。
SQL> select 2 dump(TREAT(ty1 AS ty_child_1).VALUE,16), 3 dump(TREAT(ty1 AS ty_child_2).VALUE,16), 4 dump(TREAT(ty1 AS ty_child_3).VALUE,16) 5 from t1 ; DUMP(TREAT(TY1ASTY_CHILD_1).VALUE,16) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- DUMP(TREAT(TY1ASTY_CHILD_2).VALUE,16) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- DUMP(TREAT(TY1ASTY_CHILD_3).VALUE,16) ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- NULL Typ=180 Len=16: 41,41,41,41,41,41,41,41,41,41,41,41,41,41,41,41 NULL
8.在此之後，執行雜湊連線時出現以下ORA-00600錯誤：
create table t2 (n1 number) ; insert into t2 values (1) ; commit ; SQL> select t1.* from t1,t2 where t1.n1 = t2.n1 ; select t1.* from t1,t2 where t1.n1 = t2.n1 * ERROR at line 1: ORA-00600: internal error code, arguments: [rworupo.1], [16], [11], [], [], [], [], [], [], [], [], []
9.執行ctas重建表，報ORA-12899錯誤
SQL> create table t3 as select * from t1; create table t3 as select * from t1 * ERROR at line 1: ORA-12899: value too large for column ??? (actual: 16, maximum: 11)
建議：
12cR2在執行alter table move操作之前，執行下列sql語句檢查，以下查詢出來的表是不能進行move操作的。
SQL> select c.owner, c.table_name, 2 substr(qualified_col_name,1,instr(qualified_col_name,'"',1,2)) parent_type 3 from dba_tab_cols c, dba_tables t 4 where hidden_column = 'YES' and virtual_column='NO' 5 and t.owner = c.owner and t.table_name = c.table_name 6 and tablespace_name is not null 7 and qualified_col_name like 'TREAT(%' 8 group by c.owner,c.table_name, 9 substr(qualified_col_name,1,instr(qualified_col_name,'"',1,2)) 10 having count(*) > 2 ; OWNER TABLE_NAME PARENT_TYPE ------------------------------ ------------------------------ ------------------------------ SYS AQ$_KUPC$DATAPUMP_QUETAB_1_P TREAT("USER_DATA" SYS KUPC$DATAPUMP_QUETAB_1 TREAT("USER_DATA" SYS T1 TREAT("TY1" SYS KUPC$DATAPUMP_QUETAB TREAT("USER_DATA"
經過測試資料使用expdp和exp是可以把資料匯出來的
[oracle@ol6 ~]$ expdp system/oracle dumpfile=a.dmp DIRECTORY=ORACLE_HOME tables=t1; Export: Release 12.2.0.1.0 - Production on Wed Sep 26 17:27:11 2018 Copyright (c) 1982, 2017, Oracle and/or its affiliates. All rights reserved. Connected to: Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production Warning: Oracle Data Pump operations are not typically needed when connected to the root or seed of a container database. Starting "SYSTEM"."SYS_EXPORT_TABLE_01": system/******** dumpfile=a.dmp DIRECTORY=ORACLE_HOME tables=t1 Processing object type TABLE_EXPORT/TABLE/TABLE_DATA Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS Processing object type TABLE_EXPORT/TABLE/STATISTICS/MARKER Processing object type TABLE_EXPORT/TABLE/TABLE . . exported "SYSTEM"."T1" 9.445 KB 1 rows Master table "SYSTEM"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded ****************************************************************************** Dump file set for SYSTEM.SYS_EXPORT_TABLE_01 is: /u01/app/oracle/product/12.2.0.1/db_1/a.dmp Job "SYSTEM"."SYS_EXPORT_TABLE_01" successfully completed at Wed Sep 26 17:27:41 2018 elapsed 0 00:00:30 [oracle@ol6 ~]$ exp system/oracle tables=t1; Export: Release 12.2.0.1.0 - Production on Wed Sep 26 17:24:30 2018 Copyright (c) 1982, 2017, Oracle and/or its affiliates. All rights reserved. EXP-00056: ORACLE error 28002 encountered ORA-28002: the password will expire within 7 days Connected to: Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production Export done in US7ASCII character set and AL16UTF16 NCHAR character set server uses AL32UTF8 character set (possible charset conversion) About to export specified tables via Conventional Path ... . . exporting table T1 1 rows exported Export terminated successfully without warnings.
目前在MOS上查不到該問題相關的Bug。建議做move前先執行SQL檢查。
參考文件：https://nenadnoveljic.com/blog/corruption-alter-table-move-oracle-12-2/