联系:手机/微信(+86 17813235971) QQ(107644445)
作者:惜分飞©版权所有[未经本人同意,不得以任何形式转载,否则有进一步追究法律责任的权利.]
今天客户说了一个我感觉有意思的需求:在一个库上的一张表记录所有库的ddl操作,实现方式:在一个库上建立表和触发器,其他库上通过dblink+同义词+触发器实现ddl操作记录到远程的表中.他当时写了一个触发器,但是有错误,想让我协助解决.在我们的一起努力下,解决了该触发器在dblink同义词的库上出错的问题.我这里测试使用的是10g的库做为存储所有库的ddl记录的库,11g库做为一个通过dblink插入ddl操作记录的库.
在10g数据库库中操作
1.创建记录ddl操作表
SQL> conn chf/xifenfei Connected. SQL> create table t_ddl_audit( 2 db_name varchar2(30), 3 login_user varchar2(30), 4 ddl_time date, 5 ip_address varchar2(20), 6 audsid varchar2(20), 7 schema_user varchar2(30), 8 schema_object varchar2(40), 9 login_tool varchar2(40), 10 os_user varchar2(40), 11 ddl_sql varchar2(4000)); Table created.
2.创建触发器
SQL> create or replace trigger tri_ddl_audit 2 before ddl on database 3 declare 4 n number; 5 str_stmt varchar2(4000); 6 sql_text ora_name_list_t; 7 l_trace number; 8 v_module varchar2(50); 9 v_action varchar2(50); 10 str_session v$session%rowtype; 11 begin 12 n := ora_sql_txt(sql_text); 13 for i in 1 .. n loop 14 str_stmt := substr(str_stmt || sql_text(i), 1, 3000); 15 end loop; 16 dbms_application_info.READ_MODULE(v_module, v_action); 17 INSERT INTO chf.t_ddl_audit 18 (db_name, 19 login_user, 20 ddl_time, 21 ip_address, 22 audsid, 23 schema_user, 24 schema_object, 25 login_tool, 26 os_user, 27 ddl_sql) 28 VALUES 29 (sys_context('USERENV', 'db_name'), 30 ora_login_user, 31 SYSDATE, 32 sys_context('USERENV', 'IP_ADDRESS'), 33 userenv('SESSIONID'), 34 ora_dict_obj_owner, 35 ora_dict_obj_name, 36 v_module, 37 sys_context('userenv', 'os_user'), 38 str_stmt); 39 exception 40 when no_data_found then 41 null; 42 end; 43 / Trigger created.
3.测试触发器
SQL> conn chf/xifenfei Connected. SQL> create table t_xff as select * from dba_tables where rownum=1; Table created. SQL> select db_name,login_user,ddl_sql from t_ddl_audit; DB_NAME LOGIN_USER ------------------------------ ------------------------------ DDL_SQL ----------------------------------------------------------------- XFF CHF create table t_xff as select * from dba_tables where rownum=1
在11g数据库中操作
1.创建dblink和同义词
SQL> create database link "ora10g_dblink" 2 connect to chf 3 identified by "xifenfei" 4 using 'ora10g'; Database link created. SQL> create synonym t_ddl_audit for t_ddl_audit@ora10g_dblink; Synonym created.
2.第一次创建触发器
SQL> create or replace trigger tri_ddl_audit 2 before ddl on database 3 declare 4 n number; 5 str_stmt varchar2(4000); 6 sql_text ora_name_list_t; 7 l_trace number; 8 v_module varchar2(50); 9 v_action varchar2(50); 10 str_session v$session%rowtype; 11 begin 12 n := ora_sql_txt(sql_text); 13 for i in 1 .. n loop 14 str_stmt := substr(str_stmt || sql_text(i), 1, 3000); 15 end loop; 16 dbms_application_info.READ_MODULE(v_module, v_action); 17 INSERT INTO t_ddl_audit 18 (db_name, 19 login_user, 20 ddl_time, 21 ip_address, 22 audsid, 23 schema_user, 24 schema_object, 25 login_tool, 26 os_user, 27 ddl_sql) 28 VALUES 29 (sys_context('USERENV', 'db_name'), 30 ora_login_user, 31 SYSDATE, 32 sys_context('USERENV', 'IP_ADDRESS'), 33 userenv('SESSIONID'), 34 ora_dict_obj_owner, 35 ora_dict_obj_name, 36 v_module, 37 sys_context('userenv', 'os_user'), 38 str_stmt); 39 exception 40 when no_data_found then 41 null; 42 end; 43 / Trigger created.
3.测试触发器
SQL> create table t_xff as select * from dba_objects where rownum<10; create table t_xff as select * from dba_objects where rownum<10 * ERROR at line 1: ORA-00604: error occurred at recursive SQL level 1 ORA-02070: database does not support in this context ORA-06512: at line 15
出现ORA-02070错误,估计是类此sys_context(‘userenv’, ‘os_user’)导致。
4.第二次创建触发器
SQL> create or replace trigger tri_ddl_audit 2 before ddl on database 3 declare 4 n number; 5 str_stmt varchar2(4000); 6 sql_text ora_name_list_t; 7 l_trace number; 8 v_module varchar2(50); 9 v_action varchar2(50); 10 v_db_name varchar2(50); 11 v_ip_addr varchar2(50); 12 v_os varchar2(50); 13 v_session_id varchar2(50); 14 str_session v$session%rowtype; 15 begin 16 n := ora_sql_txt(sql_text); 17 for i in 1 .. n loop 18 str_stmt := substr(str_stmt || sql_text(i), 1, 3000); 19 end loop; 20 dbms_application_info.READ_MODULE(v_module, v_action); 21 v_db_name :=sys_context('USERENV', 'db_name'); 22 v_ip_addr :=sys_context('USERENV', 'IP_ADDRESS'); 23 v_os:=sys_context('userenv', 'os_user'); 24 v_session_id:=userenv('SESSIONID'); 25 INSERT INTO t_ddl_audit 26 (db_name, 27 login_user, 28 ddl_time, 29 ip_address, 30 audsid, 31 schema_user, 32 schema_object, 33 login_tool, 34 os_user, 35 ddl_sql) 36 VALUES 37 (v_db_name, 38 ora_login_user, 39 SYSDATE, 40 v_ip_addr, 41 v_session_id, 42 ora_dict_obj_owner, 43 ora_dict_obj_name, 44 v_module, 45 v_os, 46 str_stmt); 47 exception 48 when no_data_found then 49 null; 50 end; 51 / Trigger created.
5.继续测试触发器
SQL> drop table t3; drop table t3 * ERROR at line 1: ORA-00604: error occurred at recursive SQL level 1 ORA-02069: global_names parameter must be set to TRUE for this operation ORA-06512: at line 23
根据ORA-02069,查询资料发现是通过dblink插入数据使用了变量和常量的方式混合使用导致该错误,修改触发器全部使用变量方式
6.第三次创建触发器
SQL> create or replace trigger tri_ddl_audit 2 before ddl on database 3 declare 4 n number; 5 str_stmt varchar2(4000); 6 sql_text ora_name_list_t; 7 l_trace number; 8 v_module varchar2(50); 9 v_action varchar2(50); 10 v_db_name varchar2(50); 11 v_ip_addr varchar2(50); 12 v_os varchar2(50); 13 v_session_id varchar2(50); 14 v_loginuser varchar2(50); 15 v_obj_name varchar2(50); 16 v_owner varchar2(50); 17 str_session v$session%rowtype; 18 begin 19 n := ora_sql_txt(sql_text); 20 for i in 1 .. n loop 21 str_stmt := substr(str_stmt || sql_text(i), 1, 3000); 22 end loop; 23 dbms_application_info.READ_MODULE(v_module, v_action); 24 v_db_name :=sys_context('USERENV', 'db_name'); 25 v_ip_addr :=sys_context('USERENV', 'IP_ADDRESS'); 26 v_os:=sys_context('userenv', 'os_user'); 27 v_session_id:=userenv('SESSIONID'); 28 v_loginuser:= ora_login_user; 29 v_owner:=ora_dict_obj_owner; 30 v_obj_name:=ora_dict_obj_name; 31 INSERT INTO t_ddl_audit 32 (db_name, 33 login_user, 34 ddl_time, 35 ip_address, 36 audsid, 37 schema_user, 38 schema_object, 39 login_tool, 40 os_user, 41 ddl_sql) 42 VALUES 43 (v_db_name, 44 v_loginuser, 45 SYSDATE, 46 v_ip_addr, 47 v_session_id, 48 v_owner, 49 v_obj_name, 50 v_module, 51 v_os, 52 str_stmt); 53 exception 54 when no_data_found then 55 null; 56 end; 57 / Trigger created.
7.测试触发器
SQL> create table t_xff11 as select * from dba_tables where rownum<10; Table created. SQL> select db_name,login_user,ddl_sql from t_ddl_audit; DB_NAME LOGIN_USER ------------------------------ ------------------------------ DDL_SQL ----------------------------------------------------------------- ora11g CHF create table t_xff11 as select * from dba_tables where rownum<10 XFF CHF create table t_xff as select * from dba_tables where rownum=1
补充说明
这个方案个人感觉是一个实验室中的方案,在实际的生成环境中很难应用上
1.trigger记录ddl操作本身效率不高
2.如果某个库不能访问存储ddl操作的表的数据库,将导致该数据库所有ddl操作hang住,从而可能使得该数据库hang住的风险.
您好,想问一下如果在DDL触发器中,查询被修改对象的信息,怎么总是查询不到呢?
例如一个用户重命名表TEST_TRIGGER,其OBJECT_ID是50580,那么在AFTER ALTER 触发器中,下列语句查询失败:select * from dba_objects t where t.object_id=50580。
求解答啊,多谢 联系方式365781062@qq.com