11g包dbms_parallel_execute在海量数据处理过程中的应用
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各位技术爱好者，看完本文后，你可以掌握如下的技能，也可以学到一些其它你所不知道的知识，~O(∩_∩)O~：
① 11g包dbms_parallel_execute在海量数据处理过程中的应用
注意：本篇BLOG中代码部分需要特别关注的地方我都用***背景和红色字体来表示，比如下边的例子中，thread 1的最大归档日志号为33，thread 2的最大归档日志号为43是需要特别关注的地方。
List of Archived Logs in backup set 11
Thrd Seq Low SCN Low Time Next SCN Next Time
---- ------- ---------- ------------------- ---------- ---------
1 32 1621589 2015-05-29 11:09:52 1625242 2015-05-29 11:15:48
1 33 1625242 2015-05-29 11:15:48 1625293 2015-05-29 11:15:58
2 42 1613951 2015-05-29 10:41:18 1625245 2015-05-29 11:15:49
2 43 1625245 2015-05-29 11:15:49 1625253 2015-05-29 11:15:53
本文如有错误或不完善的地方请大家多多指正，ITPUB留言或QQ皆可，您的批评指正是我写作的最大动力。
11.2.0.1 RHEL6.5
Oracle中如何更新一张大表记录
http://blog.itpub.net/26736162/viewspace-1684095/
使用11g dbms_parallel_execute执行并行更新（下）
http://blog.itpub.net/26736162/viewspace-1683913/
使用11g dbms_parallel_execute执行并行更新（上）
http://blog.itpub.net/26736162/viewspace-1683912/
一个朋友own_my要处理批量数据，但是脚本跑的太慢了，于是网上搜到了dbms_parallel_execute这个包，用完后给我说这个包非常强大，于是我也学习学习，关于优化一直是我喜欢的内容，在参考了大神realkid4 的blog后，我自己也做了做实验，感觉很强大，记录在此。
参考大神的blog：http://blog.itpub.net/17203031/
测试dbms_parallel_execute包在海量数据处理过程中的应用。
[oracle@etlhost206 ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Wed Jun 3 13:40:34 2015
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL> CONN LHR/lhr
Connected.
SQL> CREATE TABLE T AS SELECT * FROM DBA_OBJECTS;
Table created.
SQL> insert into t select * from t;
76369 rows created.
SQL> insert into t select * from t;
152738 rows created.
SQL> insert into t select * from t;
305476 rows created.
SQL> COMMIT;
Commit complete.
SQL> insert into t select * from t;
610952 rows created.
SQL> insert into t select * from t;
1221904 rows created.
SQL> insert into t select * from t;
2443808 rows created.
SQL> insert into t select * from t;
4887616 rows created.
SQL> COMMIT;
Commit complete.
SQL> insert into t select * from t;
9775232 rows created.
SQL> COMMIT;
Commit complete.
SQL> insert into t select * from t;
19550464 rows created.
SQL> COMMIT;
Commit complete.
SQL> select bytes/1024/1024 from dba_segments a where a.segment_name='T';
BYTES/1024/1024
---------------
4341
SQL> SELECT COUNT(1) FROM T;
COUNT(1)
----------
39100928
SQL> show parameter job
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
job_queue_processes integer 1000
SQL> show parameter cpu
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
cpu_count integer 8
parallel_threads_per_cpu integer 2
resource_manager_cpu_allocation integer 8
SQL> set timing on
SQL> set time on;
15:50:01 SQL>
15:50:02 SQL> show parameter job
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
job_queue_processes integer 1000
15:50:09 SQL> select bytes/1024/1024 from dba_segments a where a.segment_name='T';
BYTES/1024/1024
---------------
4341
Elapsed: 00:00:00.41
15:50:31 SQL> declare
15:50:39 2 vc_task varchar2(100);
15:50:39 3 vc_sql varchar2(1000);
15:50:39 4 n_try number;
15:50:39 5 n_status number;
15:50:39 6 begin
15:50:39 7 --Define the Task
15:50:39 8 vc_task := 'Task 1: By Rowid'; --Task名称
15:50:39 9 dbms_parallel_execute.create_task(task_name => vc_task); --手工定义一个Task任务；
15:50:39 10
15:50:39 11 --Define the Spilt
15:50:39 12 dbms_parallel_execute.create_chunks_by_rowid(task_name => vc_task,
15:50:39 13 table_owner => 'LHR',
15:50:39 14 table_name => 'T',
15:50:39 15 by_row => true,
15:50:39 16 chunk_size => 10000); --定义Chunk
15:50:39 17
15:50:39 18 vc_sql := 'update /*+ ROWID(dda) */ t set DATA_OBJECT_ID=object_id+1 where rowid between :start_id and :end_id';
15:50:40 19 --Run the task
15:50:40 20 dbms_parallel_execute.run_task(task_name => vc_task,
15:50:40 21 sql_stmt => vc_sql,
15:50:40 22 language_flag => dbms_sql.native,
15:50:40 23 parallel_level => 4); --执行任务，确定并行度
15:50:40 24
15:50:40 25 --Controller
15:50:40 26 n_try := 0;
15:50:40 27 n_status := dbms_parallel_execute.task_status(task_name => vc_task);
15:50:40 28 while (n_try < 2 and n_status != dbms_parallel_execute.FINISHED) loop
15:50:40 29 dbms_parallel_execute.resume_task(task_name => vc_task);
15:50:40 30 n_status := dbms_parallel_execute.task_status(task_name => vc_task);
15:50:40 31 end loop;
15:50:40 32
15:50:40 33 --Deal with Result
15:50:40 34 dbms_parallel_execute.drop_task(task_name => vc_task);
15:50:40 35 end;
15:50:40 36 /
PL/SQL procedure successfully completed.
Elapsed: 00:03:50.78
15:58:05 SQL>
15:58:06 SQL> create index idx_t_id on t(object_id) nologging parallel 4;
Index created.
Elapsed: 00:01:35.12
16:00:05 SQL> alter index idx_t_id noparallel;
Index altered.
Elapsed: 00:00:00.07
16:00:15 SQL>
16:02:51 SQL> declare
16:02:52 2 vc_task varchar2(100);
16:02:52 3 vc_sql varchar2(1000);
16:02:52 4 n_try number;
16:02:52 5 n_status number;
16:02:52 6 begin
16:02:52 7 --Define the Task
16:02:52 8 vc_task := 'Task 2: By Number Col';
16:02:52 9 dbms_parallel_execute.create_task(task_name => vc_task);
16:02:52 10
16:02:52 11 --Define the Spilt
16:02:52 12 dbms_parallel_execute.create_chunks_by_number_col(task_name => vc_task,
16:02:52 13 table_owner => 'LHR',
16:02:52 14 table_name => 'T',
16:02:52 15 table_column => 'OBJECT_ID',
16:02:52 16 chunk_size => 100000); --定义chunk
16:02:53 17 16:02:53 18 vc_sql := 'update /*+ ROWID(dda) */ t set DATA_OBJECT_ID=object_id+1 where object_id between :start_id and :end_id';
16:02:53 19 --Run the task
16:02:53 20 dbms_parallel_execute.run_task(task_name => vc_task,
16:02:53 21 sql_stmt => vc_sql,
16:02:53 22 language_flag => dbms_sql.native,
16:02:53 23 parallel_level => 4);
16:02:53 24
16:02:53 25 --Controller
16:02:53 26 n_try := 0;
16:02:53 27 n_status := dbms_parallel_execute.task_status(task_name => vc_task);
16:02:53 28 while (n_try < 2 and n_status != dbms_parallel_execute.FINISHED) loop
16:02:53 29 dbms_parallel_execute.resume_task(task_name => vc_task);
16:02:53 30 n_status := dbms_parallel_execute.task_status(task_name => vc_task);
16:02:53 31 end loop;
16:02:53 32
16:02:53 33 --Deal with Result
16:02:53 34 dbms_parallel_execute.drop_task(task_name => vc_task);
16:02:53 35 end;
16:02:53 36 /
^Cdeclare
*
ERROR at line 1:
ORA-01013: user requested cancel of current operation
ORA-06512: at "SYS.DBMS_LOCK", line 201
ORA-06512: at "SYS.DBMS_PARALLEL_EXECUTE", line 44
ORA-06512: at "SYS.DBMS_PARALLEL_EXECUTE", line 390
ORA-06512: at "SYS.DBMS_PARALLEL_EXECUTE", line 417
ORA-06512: at line 20
Elapsed: 00:07:12.08
16:11:36 SQL>
16:11:36 SQL> EXEC dbms_parallel_execute.drop_task(task_name => 'Task 2: By Number Col');
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.11
16:31:53 SQL> declare
16:32:05 2 vc_task varchar2(100);
16:32:05 3 vc_sql varchar2(1000);
16:32:05 4 vc_sql_mt varchar2(1000);
16:32:05 5 n_try number;
16:32:05 6 n_status number;
16:32:05 7 begin
16:32:05 8 --Define the Task
16:32:05 9 vc_task := 'Task 3: By SQL';
16:32:05 10 dbms_parallel_execute.create_task(task_name => vc_task);
16:32:05 11
16:32:05 12 --Define the Spilt
16:32:05 13 vc_sql_mt := 'select distinct object_id, object_id from t';
16:32:05 14 dbms_parallel_execute.create_chunks_by_SQL(task_name => vc_task,
16:32:05 15 sql_stmt => vc_sql_mt,
16:32:05 16 by_rowid => false);
16:32:05 17
16:32:05 18 vc_sql := 'update /*+ ROWID(dda) */t set DATA_OBJECT_ID=object_id+1 where object_id between :start_id and :end_id';
16:32:05 19 --Run the task
16:32:05 20 dbms_parallel_execute.run_task(task_name => vc_task,
16:32:05 21 sql_stmt => vc_sql,
16:32:05 22 language_flag => dbms_sql.native,
16:32:05 23 parallel_level => 4);
16:32:05 24
16:32:05 25 --Controller
16:32:05 26 n_try := 0;
16:32:05 27 n_status := dbms_parallel_execute.task_status(task_name => vc_task);
16:32:05 28 while (n_try < 2 and n_status != dbms_parallel_execute.FINISHED) loop
16:32:05 29 dbms_parallel_execute.resume_task(task_name => vc_task);
16:32:05 30 n_status := dbms_parallel_execute.task_status(task_name => vc_task);
16:32:05 31 end loop;
16:32:05 32
16:32:05 33 --Deal with Result
16:32:05 34 dbms_parallel_execute.drop_task(task_name => vc_task);
16:32:05 35 end;
16:32:05 36 /
^Cdeclare
*
ERROR at line 1:
ORA-01013: user requested cancel of current operation
ORA-06512: at "SYS.DBMS_PARALLEL_EXECUTE_INTERNAL", line 634
ORA-06512: at "SYS.DBMS_PARALLEL_EXECUTE", line 163
ORA-06512: at line 14
Elapsed: 00:01:09.08
16:33:14 SQL> EXEC dbms_parallel_execute.drop_task(task_name => 'Task 3: By SQL');
PL/SQL procedure successfully completed.
SELECT * FROM DBA_PARALLEL_EXECUTE_TASKS;
SELECT * FROM DBA_PARALLEL_EXECUTE_CHUNKS;
SELECT count(1) FROM DBA_PARALLEL_EXECUTE_CHUNKS;
select status, count(*) from user_parallel_execute_chunks group by status;
select D.owner,D.job_name,D.JOB_STYLE,D.JOB_TYPE,D.JOB_ACTION from dba_scheduler_jobs d where d.owner='LHR';
告警日志：
Wed Jun 03 15:53:48 2015
Archived Log entry 1202 added for thread 1 sequence 2669 ID 0x6779dfc4 dest 1:
Thread 1 advanced to log sequence 2671 (LGWR switch)
Current log# 4 seq# 2671 mem# 0: /app/oracle/flash_recovery_area/CNYDB/onlinelog/o1_mf_4_bpxd8g7v_.log
Wed Jun 03 15:53:49 2015
Archived Log entry 1203 added for thread 1 sequence 2670 ID 0x6779dfc4 dest 1:
Wed Jun 03 15:53:57 2015
Thread 1 advanced to log sequence 2672 (LGWR switch)
Current log# 5 seq# 2672 mem# 0: /app/oracle/flash_recovery_area/CNYDB/onlinelog/o1_mf_5_bpxdbwdz_.log
Wed Jun 03 15:53:58 2015
Archived Log entry 1204 added for thread 1 sequence 2671 ID 0x6779dfc4 dest 1:
Thread 1 advanced to log sequence 2673 (LGWR switch)
Current log# 1 seq# 2673 mem# 0: /app/oracle/oradata/CNYDB/redo01.log
Wed Jun 03 15:54:04 2015
Archived Log entry 1205 added for thread 1 sequence 2672 ID 0x6779dfc4 dest 1:
Thread 1 advanced to log sequence 2674 (LGWR switch)
Current log# 6 seq# 2674 mem# 0: /app/oracle/flash_recovery_area/CNYDB/onlinelog/o1_mf_6_bpxdcjx2_.log
Wed Jun 03 15:54:05 2015
Archived Log entry 1206 added for thread 1 sequence 2673 ID 0x6779dfc4 dest 1:
由告警日志可以看出redo切换非常迅速，归档来不及，所以还是需要在空闲的时候来做实验。
SELECT * FROM DBA_PARALLEL_EXECUTE_CHUNKS;
SELECT * FROM DBA_PARALLEL_EXECUTE_TASKS;
select status, count(*) from dba_parallel_execute_chunks group by status;
select sid, serial#, status, PROGRAM, SQL_ID, event from v$session where action like 'TASK$%';
select D.owner,D.job_name,D.JOB_STYLE,D.JOB_TYPE,D.JOB_ACTION from dba_scheduler_jobs d where d.owner='LHR';
由实验可以看出，采用dbms_parallel_execute.create_chunks_by_rowid方法，4千万的数据量大约4G大小的表更新完大约4分钟，这个速度还是可以的，另外2种方式更新下来速度太慢就没有测试了，具体可以参考这里：http://blog.itpub.net/26736162/viewspace-1683912/，http://blog.itpub.net/26736162/viewspace-1683913/。
declare
vc_task varchar2(100);
vc_sql varchar2(1000);
n_try number;
n_status number;
begin
--Define the Task
vc_task := 'Task 1: By Rowid'; --Task名称
dbms_parallel_execute.create_task(task_name => vc_task); --手工定义一个Task任务；
--Define the Spilt
dbms_parallel_execute.create_chunks_by_rowid(task_name => vc_task,
table_owner => 'LHR',
table_name => 'T',
by_row => true,
chunk_size => 10000); --定义Chunk
vc_sql := 'update /*+ ROWID(dda) */ t set DATA_OBJECT_ID=object_id+1 where rowid between :start_id and :end_id';
--Run the task
dbms_parallel_execute.run_task(task_name => vc_task,
sql_stmt => vc_sql,
language_flag => dbms_sql.native,
parallel_level => 4); --执行任务，确定并行度
--Controller
n_try := 0;
n_status := dbms_parallel_execute.task_status(task_name => vc_task);
while (n_try < 2 and n_status != dbms_parallel_execute.FINISHED) loop
dbms_parallel_execute.resume_task(task_name => vc_task);
n_status := dbms_parallel_execute.task_status(task_name => vc_task);
end loop;
--Deal with Result
dbms_parallel_execute.drop_task(task_name => vc_task);
end;
/
declare
vc_task varchar2(100);
vc_sql varchar2(1000);
n_try number;
n_status number;
begin
--Define the Task
vc_task := 'Task 2: By Number Col';
dbms_parallel_execute.create_task(task_name => vc_task);
--Define the Spilt
dbms_parallel_execute.create_chunks_by_number_col(task_name => vc_task,
table_owner => 'LHR',
table_name => 'T',
table_column => 'OBJECT_ID',
chunk_size => 10000); --定义chunk
vc_sql := 'update /*+ ROWID(dda) */ t set DATA_OBJECT_ID=object_id+1 where object_id between :start_id and :end_id';
--Run the task
dbms_parallel_execute.run_task(task_name => vc_task,
sql_stmt => vc_sql,
language_flag => dbms_sql.native,
parallel_level => 4);
--Controller
n_try := 0;
n_status := dbms_parallel_execute.task_status(task_name => vc_task);
while (n_try < 2 and n_status != dbms_parallel_execute.FINISHED) loop
dbms_parallel_execute.resume_task(task_name => vc_task);
n_status := dbms_parallel_execute.task_status(task_name => vc_task);
end loop;
--Deal with Result
dbms_parallel_execute.drop_task(task_name => vc_task);
end;
/
declare
vc_task varchar2(100);
vc_sql varchar2(1000);
vc_sql_mt varchar2(1000);
n_try number;
n_status number;
begin
--Define the Task
vc_task := 'Task 3: By SQL';
dbms_parallel_execute.create_task(task_name => vc_task);
--Define the Spilt
vc_sql_mt := 'select distinct object_id, object_id from t';
dbms_parallel_execute.create_chunks_by_SQL(task_name => vc_task,
sql_stmt => vc_sql_mt,
by_rowid => false);
vc_sql := 'update /*+ ROWID(dda) */t set DATA_OBJECT_ID=object_id+1 where object_id between :start_id and :end_id';
--Run the task
dbms_parallel_execute.run_task(task_name => vc_task,
sql_stmt => vc_sql,
language_flag => dbms_sql.native,
parallel_level => 4);
--Controller
n_try := 0;
n_status := dbms_parallel_execute.task_status(task_name => vc_task);
while (n_try < 2 and n_status != dbms_parallel_execute.FINISHED) loop
dbms_parallel_execute.resume_task(task_name => vc_task);
n_status := dbms_parallel_execute.task_status(task_name => vc_task);
end loop;
--Deal with Result
dbms_parallel_execute.drop_task(task_name => vc_task);
end;
/
...........................................................................................................................................................................................
本文作者：小麦苗，只专注于数据库的技术，更注重技术的运用
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