【DB笔试面试606】在Oracle中，coe_xfr_sql_profile.sql脚本的作用是什么？
- 2019 年 10 月 10 日
- 筆記
题目部分
在Oracle中，coe_xfr_sql_profile.sql脚本的作用是什么？
♣
答案部分
使用coe_xfr_sql_profile.sql脚本生成sqlprof_attr数据
最麻烦的sqlprof_attr('FULL(t1@SEL$1)')是这里的格式如何写，在Mos上的文章note 215187.1中的sqlt.zip的目录utl中提供了脚本coe_xfr_sql_profile.sql可以生成这些信息。
1.建立测试表和数据
SYS@dlhr> select * from v$version; BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production PL/SQL Release 11.2.0.4.0 - Production CORE 11.2.0.4.0 Production TNS for IBM/AIX RISC System/6000: Version 11.2.0.4.0 - Production NLSRTL Version 11.2.0.4.0 - Production LHR@dlhr> create table scott.test as select * from dba_objects; Table created. LHR@dlhr> create index scott.idx_test_01 on scott.test(object_id); Index created. LHR@dlhr> exec dbms_stats.gather_table_stats('scott','test',cascade=>true); PL/SQL procedure successfully completed. LHR@dlhr> update scott.test set object_id=10 where object_id>10; LHR@dlhr> commit; Commit complete. LHR@dlhr> select OBJECT_ID ,count(1) from scott.test group by OBJECT_ID; OBJECT_ID COUNT(1) ---------- ---------- 6 1 7 1 5 1 8 1 3 1 2 1 10 87076 4 1 9 1 9 rows selected.
2.执行查询语句
执行原有的查询语句，查看执行计划发现走索引，实际上这时表中大部分行的OBJECT_ID都已经被更新为10，所以走索引是不合理的。
LHR@dlhr> set autot traceonly explain stat LHR@dlhr> LHR@dlhr> select * from scott.test where object_id=10; 87076 rows selected. Execution Plan ---------------------------------------------------------- Plan hash value: 3384190782 ------------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 98 | 2 (0)| 00:00:01 | | 1 | TABLE ACCESS BY INDEX ROWID| TEST | 1 | 98 | 2 (0)| 00:00:01 | |* 2 | INDEX RANGE SCAN | IDX_TEST_01 | 1 | | 1 (0)| 00:00:01 | ------------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 2 - access("OBJECT_ID"=10) Statistics ---------------------------------------------------------- 0 recursive calls 0 db block gets 13060 consistent gets 0 physical reads 0 redo size 9855485 bytes sent via SQL*Net to client 64375 bytes received via SQL*Net from client 5807 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 87076 rows processed LHR@dlhr> select /*+ full(test)*/* from scott.test where object_id=10; 87076 rows selected. Execution Plan ---------------------------------------------------------- Plan hash value: 217508114 -------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | -------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 98 | 351 (2)| 00:00:05 | |* 1 | TABLE ACCESS FULL| TEST | 1 | 98 | 351 (2)| 00:00:05 | -------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter("OBJECT_ID"=10) Statistics ---------------------------------------------------------- 1 recursive calls 0 db block gets 6973 consistent gets 0 physical reads 0 redo size 4159482 bytes sent via SQL*Net to client 64375 bytes received via SQL*Net from client 5807 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 87076 rows processed
3.查询上面两个语句的SQL_ID、PLAN_HASH_VALUE
LHR@dlhr> set autot off LHR@dlhr> LHR@dlhr> col sql_text format a100 LHR@dlhr> select sql_text,sql_id,plan_hash_value from v$sql 2 where sql_text like 'select * from scott.test where object_id=10%'; SQL_TEXT SQL_ID PLAN_HASH_VALUE ---------------------------------------------------------------------------------------------------- ------------- --------------- select * from scott.test where object_id=10 cpk9jsg2qt52r 3384190782 LHR@dlhr> select sql_text,sql_id,plan_hash_value from v$sql 2 where sql_text like 'select /*+ full(test)*/* from scott.test where object_id=10%'; SQL_TEXT SQL_ID PLAN_HASH_VALUE ---------------------------------------------------------------------------------------------------- ------------- --------------- select /*+ full(test)*/* from scott.test where object_id=10 06c2mucgn6t5g 217508114
4.把coe_xfr_sql_profile.sql放在$ORACLE_HOME/rdbms/admin下，或者放在/tmp下都可以。
5.对上面的两个SQL产生outline data的sql.
[ZHLHRSPMDB2:oracle]:/oracle>cd /tmp [ZHLHRSPMDB2:oracle]:/tmp> [ZHLHRSPMDB2:oracle]:/tmp>sqlplus / as sysdba SQL*Plus: Release 11.2.0.4.0 Production on Thu May 26 09:15:14 2016 Copyright (c) 1982, 2013, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production With the Partitioning, Real Application Clusters, OLAP, Data Mining and Real Application Testing options SYS@dlhr> @$ORACLE_HOME/rdbms/admin/coe_xfr_sql_profile.sql cpk9jsg2qt52r 3384190782 Parameter 1: SQL_ID (required) PLAN_HASH_VALUE AVG_ET_SECS --------------- ----------- 3384190782 .046 Parameter 2: PLAN_HASH_VALUE (required) Values passed to coe_xfr_sql_profile: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SQL_ID : "cpk9jsg2qt52r" PLAN_HASH_VALUE: "3384190782" SQL>BEGIN 2 IF :sql_text IS NULL THEN 3 RAISE_APPLICATION_ERROR(-20100, 'SQL_TEXT for SQL_ID &&sql_id. was not found in memory (gv$sqltext_with_newlines) or AWR (dba_hist_sqltext).'); 4 END IF; 5 END; 6 / SQL>SET TERM OFF; SQL>BEGIN 2 IF :other_xml IS NULL THEN 3 RAISE_APPLICATION_ERROR(-20101, 'PLAN for SQL_ID &&sql_id. and PHV &&plan_hash_value. was not found in memory (gv$sql_plan) or AWR (dba_hist_sql_plan).'); 4 END IF; 5 END; 6 / SQL>SET TERM OFF; Execute coe_xfr_sql_profile_cpk9jsg2qt52r_3384190782.sql on TARGET system in order to create a custom SQL Profile with plan 3384190782 linked to adjusted sql_text. COE_XFR_SQL_PROFILE completed. SQL>@$ORACLE_HOME/rdbms/admin/coe_xfr_sql_profile.sql 06c2mucgn6t5g 217508114 Parameter 1: SQL_ID (required) PLAN_HASH_VALUE AVG_ET_SECS --------------- ----------- 217508114 .113 Parameter 2: PLAN_HASH_VALUE (required) Values passed to coe_xfr_sql_profile: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SQL_ID : "06c2mucgn6t5g" PLAN_HASH_VALUE: "217508114" SQL>BEGIN 2 IF :sql_text IS NULL THEN 3 RAISE_APPLICATION_ERROR(-20100, 'SQL_TEXT for SQL_ID &&sql_id. was not found in memory (gv$sqltext_with_newlines) or AWR (dba_hist_sqltext).'); 4 END IF; 5 END; 6 / SQL>SET TERM OFF; SQL>BEGIN 2 IF :other_xml IS NULL THEN 3 RAISE_APPLICATION_ERROR(-20101, 'PLAN for SQL_ID &&sql_id. and PHV &&plan_hash_value. was not found in memory (gv$sql_plan) or AWR (dba_hist_sql_plan).'); 4 END IF; 5 END; 6 / SQL>SET TERM OFF; Execute coe_xfr_sql_profile_06c2mucgn6t5g_217508114.sql on TARGET system in order to create a custom SQL Profile with plan 217508114 linked to adjusted sql_text. COE_XFR_SQL_PROFILE completed.
6.替换文件coe_xfr_sql_profile_cpk9jsg2qt52r_3384190782.sql中的SYS.SQLPROF_ATTR部分，把它更改为coe_xfr_sql_profile_06c2mucgn6t5g_217508114.sql中产生的SYS.SQLPROF_ATTR部分，其中：
coe_xfr_sql_profile_cpk9jsg2qt52r_3384190782.sql的SYS.SQLPROF_ATTR：
h := SYS.SQLPROF_ATTR( q'[BEGIN_OUTLINE_DATA]', q'[IGNORE_OPTIM_EMBEDDED_HINTS]', q'[OPTIMIZER_FEATURES_ENABLE('11.2.0.4')]', q'[DB_VERSION('11.2.0.4')]', q'[ALL_ROWS]', q'[OUTLINE_LEAF(@"SEL$1")]', q'[INDEX_RS_ASC(@"SEL$1" "TEST"@"SEL$1" ("TEST"."OBJECT_ID"))]', q'[END_OUTLINE_DATA]'); --coe_xfr_sql_profile_06c2mucgn6t5g_217508114.sql的SYS.SQLPROF_ATTR： h := SYS.SQLPROF_ATTR( q'[BEGIN_OUTLINE_DATA]', q'[IGNORE_OPTIM_EMBEDDED_HINTS]', q'[OPTIMIZER_FEATURES_ENABLE('11.2.0.4')]', q'[DB_VERSION('11.2.0.4')]', q'[ALL_ROWS]', q'[OUTLINE_LEAF(@"SEL$1")]', q'[FULL(@"SEL$1" "TEST"@"SEL$1")]', q'[END_OUTLINE_DATA]'); 生成的文件在当前目录：
7.执行替换过SYS.SQLPROF_ATTR的SQL，coe_xfr_sql_profile_cpk9jsg2qt52r_3384190782.sql
SQL> @/tmp/coe_xfr_sql_profile_cpk9jsg2qt52r_3384190782.sql
SQL>@coe_xfr_sql_profile_cpk9jsg2qt52r_3384190782.sql SQL>REM SQL>REM $Header: 215187.1 coe_xfr_sql_profile_cpk9jsg2qt52r_3384190782.sql 11.4.4.4 2016/05/26 carlos.sierra $ SQL>REM SQL>REM Copyright (c) 2000-2012, Oracle Corporation. All rights reserved. SQL>REM SQL>REM AUTHOR SQL>REM [email protected] SQL>REM SQL>REM SCRIPT SQL>REM coe_xfr_sql_profile_cpk9jsg2qt52r_3384190782.sql SQL>REM SQL>REM DESCRIPTION SQL>REM This script is generated by coe_xfr_sql_profile.sql SQL>REM It contains the SQL*Plus commands to create a custom SQL>REM SQL Profile for SQL_ID cpk9jsg2qt52r based on plan hash SQL>REM value 3384190782. SQL>REM The custom SQL Profile to be created by this script SQL>REM will affect plans for SQL commands with signature SQL>REM matching the one for SQL Text below. SQL>REM Review SQL Text and adjust accordingly. SQL>REM SQL>REM PARAMETERS SQL>REM None. SQL>REM SQL>REM EXAMPLE SQL>REM SQL> START coe_xfr_sql_profile_cpk9jsg2qt52r_3384190782.sql; SQL>REM SQL>REM NOTES SQL>REM 1. Should be run as SYSTEM or SYSDBA. SQL>REM 2. User must have CREATE ANY SQL PROFILE privilege. SQL>REM 3. SOURCE and TARGET systems can be the same or similar. SQL>REM 4. To drop this custom SQL Profile after it has been created: SQL>REM EXEC DBMS_SQLTUNE.DROP_SQL_PROFILE('coe_cpk9jsg2qt52r_3384190782'); SQL>REM 5. Be aware that using DBMS_SQLTUNE requires a license SQL>REM for the Oracle Tuning Pack. SQL>REM 6. If you modified a SQL putting Hints in order to produce a desired SQL>REM Plan, you can remove the artifical Hints from SQL Text pieces below. SQL>REM By doing so you can create a custom SQL Profile for the original SQL>REM SQL but with the Plan captured from the modified SQL (with Hints). SQL>REM SQL>WHENEVER SQLERROR EXIT SQL.SQLCODE; SQL>REM SQL>VAR signature NUMBER; SQL>VAR signaturef NUMBER; SQL>REM SQL>DECLARE 2 sql_txt CLOB; 3 h SYS.SQLPROF_ATTR; 4 PROCEDURE wa (p_line IN VARCHAR2) IS 5 BEGIN 6 DBMS_LOB.WRITEAPPEND(sql_txt, LENGTH(p_line), p_line); 7 END wa; 8 BEGIN 9 DBMS_LOB.CREATETEMPORARY(sql_txt, TRUE); 10 DBMS_LOB.OPEN(sql_txt, DBMS_LOB.LOB_READWRITE); 11 -- SQL Text pieces below do not have to be of same length. 12 -- So if you edit SQL Text (i.e. removing temporary Hints), 13 -- there is no need to edit or re-align unmodified pieces. 14 wa(q'[select * from scott.test where object_id=10]'); 15 DBMS_LOB.CLOSE(sql_txt); 16 h := SYS.SQLPROF_ATTR( 17 q'[BEGIN_OUTLINE_DATA]', 18 q'[IGNORE_OPTIM_EMBEDDED_HINTS]', 19 q'[OPTIMIZER_FEATURES_ENABLE('11.2.0.4')]', 20 q'[DB_VERSION('11.2.0.4')]', 21 q'[ALL_ROWS]', 22 q'[OUTLINE_LEAF(@"SEL$1")]', 23 q'[FULL(@"SEL$1" "TEST"@"SEL$1")]', 24 q'[END_OUTLINE_DATA]'); 25 :signature := DBMS_SQLTUNE.SQLTEXT_TO_SIGNATURE(sql_txt); 26 :signaturef := DBMS_SQLTUNE.SQLTEXT_TO_SIGNATURE(sql_txt, TRUE); 27 DBMS_SQLTUNE.IMPORT_SQL_PROFILE ( 28 sql_text => sql_txt, 29 profile => h, 30 name => 'coe_cpk9jsg2qt52r_3384190782', 31 description => 'coe cpk9jsg2qt52r 3384190782 '||:signature||' '||:signaturef||'', 32 category => 'DEFAULT', 33 validate => TRUE, 34 replace => TRUE, 35 force_match => FALSE /* TRUE:FORCE (match even when different literals in SQL). FALSE:EXACT (similar to CURSOR_SHARING) */ ); 36 DBMS_LOB.FREETEMPORARY(sql_txt); 37 END; 38 / PL/SQL procedure successfully completed. SQL>WHENEVER SQLERROR CONTINUE SQL>SET ECHO OFF; SIGNATURE --------------------- 10910590721604799112 SIGNATUREF --------------------- 15966118871002195466 ... manual custom SQL Profile has been created COE_XFR_SQL_PROFILE_cpk9jsg2qt52r_3384190782 completed
8.查看产生的sql profile,此时原语句在不加hint的情况下也走全表扫了select * from dba_sql_profiles;
SYS@dlhr> col sql_text for a50 SYS@dlhr> col hints for a50 SYS@dlhr> SELECT b.name,to_char(d.sql_text) sql_text, extractvalue(value(h),'.') as hints 2 FROM dba_sql_profiles d,SYS.SQLOBJ$DATA A, 3 SYS.SQLOBJ$ B, 4 TABLE(XMLSEQUENCE(EXTRACT(XMLTYPE(A.COMP_DATA), 5 '/outline_data/hint'))) h 6 where a.signature = b.signature 7 and a.category = b.category 8 and a.obj_type = b.obj_type 9 and a.plan_id = b.plan_id 10 and a.signature=d.signature 11 and D.name = 'coe_cpk9jsg2qt52r_3384190782'; NAME SQL_TEXT HINTS ------------------------------ -------------------------------------------------- -------------------------------------------------- coe_cpk9jsg2qt52r_3384190782 select * from scott.test where object_id=10 BEGIN_OUTLINE_DATA coe_cpk9jsg2qt52r_3384190782 select * from scott.test where object_id=10 IGNORE_OPTIM_EMBEDDED_HINTS coe_cpk9jsg2qt52r_3384190782 select * from scott.test where object_id=10 OPTIMIZER_FEATURES_ENABLE('11.2.0.4') coe_cpk9jsg2qt52r_3384190782 select * from scott.test where object_id=10 DB_VERSION('11.2.0.4') coe_cpk9jsg2qt52r_3384190782 select * from scott.test where object_id=10 ALL_ROWS coe_cpk9jsg2qt52r_3384190782 select * from scott.test where object_id=10 OUTLINE_LEAF(@"SEL$1") coe_cpk9jsg2qt52r_3384190782 select * from scott.test where object_id=10 FULL(@"SEL$1" "TEST"@"SEL$1") coe_cpk9jsg2qt52r_3384190782 select * from scott.test where object_id=10 END_OUTLINE_DATA 8 rows selected.
9.验证SQL Profile是否生效
SYS@dlhr> set autot traceonly explain stat SYS@dlhr> select * from scott.test where object_id=10; 87076 rows selected. Execution Plan ---------------------------------------------------------- Plan hash value: 217508114 -------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | -------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 98 | 351 (2)| 00:00:05 | |* 1 | TABLE ACCESS FULL| TEST | 1 | 98 | 351 (2)| 00:00:05 | -------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter("OBJECT_ID"=10) Note ----- - SQL profile "coe_cpk9jsg2qt52r_3384190782" used for this statement Statistics ---------------------------------------------------------- 0 recursive calls 0 db block gets 6973 consistent gets 0 physical reads 0 redo size 4159482 bytes sent via SQL*Net to client 64375 bytes received via SQL*Net from client 5807 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 87076 rows processed
注意:
① 这个测试只是为了演示通过coe_xfr_sql_profile.sql实现手动加hint的方法，实际上面的语句问题的处理最佳的方法应该是重新收集SCOTT.TEST的统计信息才对。
② 当一条SQL既有Sql Profile又有Stored Outline时，优化器优先选择stored outline。
③ 通过Sql Profile手动加Hint的方法很简单，而为SQL添加最合理的Hint才是关键。
④ 测试完后，可以通过exec dbms_sqltune.drop_sql_profile(name =>'coe_cpk9jsg2qt52r_3384190782' );删除这个Sql Profile。
⑤ 执行coe_xfr_sql_profile.sql脚本的时候用户需要对当前目录有生成文件的权限，最好当前目录是/tmp。
本文选自《Oracle程序员面试笔试宝典》，作者：李华荣。
