1. 分析及解决方案概述
分析原因
- 由于对跑批涉及的表在周末6点前进行了清数,Oracle周末自动收集统计信息的时间为早上6点,此时的表内数据量为0,导致对该表的执行计划发生了变化。因此在下午跑批过程中走的错误的执行计划,导致数据库中出现大量的排序操作或者使用临时表来存储中间结果,从而消耗大量的临时表空间,最终出现临时表空间不足的报错。
解决方案
- 恢复该表的统计信息到6点自动收集统计信息之前,使该表的执行计划恢复到6点收集统计信息前。
2. 问题描述
- 2024年4月21日18时20分,企业征信项目打来电话,说他们的跑批已经跑了40分钟还未结束,平时最多只跑20分钟,询问是否数据库出了故障问题。询问跑批涉及表数据量是否发生较大变化,项目人员回答数据量没有什么较大变化,最后排查是上午从核心提数对跑批涉及表进行了重新导数,虽然重新导数前后数据库看起来不大,但是过程中表有大量的删数和插数操作,且操作后没有收集统计信息。
操作系统版本 | RHEL 7 |
---|---|
数据库架构 | RAC集群 |
数据库版本 | 19.5.0 |
3. 问题分析
3.1 问题现象
跑批语句执行了近一个小时,语句还是没有跑过去,在后台查看当前执行sql,发现当前的等待事件在write temp,查看临时表空间90个G基本已经使用完了,随即先停止跑批任务:
1 手动SQL_MONITOR生成SQL监视报告
set linesize 500 pagesize 50000 long 999999 longchunksize 999999
select dbms_sqltune.report_sql_monitor(sql_id => '&sql_id') from dual;
2查看表的统计信息历史
select o.owner, o.object_name, o.object_id, h.savtime, h.rowcnt, h.avgrln, h.analyzetime
from dba_objects o
left join sys.wri$_optstat_tab_history h
on o.object_id = h.obj#
where o.owner = '用户名'
and o.object_name in ('表名')
order by o.object_id, h.savtime
通过表的统计信息历史可以看到该表在4月20号对表进行过统计分析,并在4月21日下午6点保存统计信息,在对表进行统计分析时表中的行数为0,应该时业务在跑批前将表清空过并重新从核心提数导入表中。因为此时表中没有数据,所以在进行统计分析后执行计划就会做出改变。
3 修改执行计划的方式
3.1.1 恢复该表的统计信息到指定时间点
exec dbms_stats.restore_table_stats(ownname => '用户名’, tabname =>'表名', as_of_timestamp => '31-JAN-20 11.23.06.652667 AM +08:00');
3.1.2 重新绑定执行计划
SPO coe_xfr_sql_profile.log;
SET DEF ON TERM OFF ECHO ON FEED OFF VER OFF HEA ON LIN 2000 PAGES 100 LONG 8000000 LONGC 800000 TRIMS ON TI OFF TIMI OFF SERVEROUT ON SIZE 1000000 NUMF "" SQLP SQL>;
SET SERVEROUT ON SIZE UNL;
REM
REM $Header: 215187.1 coe_xfr_sql_profile.sql 11.4.5.5 2013/03/01 carlos.sierra $
REM
REM Copyright (c) 2000-2013, Oracle Corporation. All rights reserved.
REM
REM AUTHOR
REM [email protected]
REM
REM SCRIPT
REM coe_xfr_sql_profile.sql
REM
REM DESCRIPTION
REM This script generates another that contains the commands to
REM create a manual custom SQL Profile out of a known plan from
REM memory or AWR. The manual custom profile can be implemented
REM into the same SOURCE system where the plan was retrieved,
REM or into another similar TARGET system that has same schema
REM objects referenced by the SQL that generated the known plan.
REM
REM PRE-REQUISITES
REM 1. Oracle Tuning Pack license.
REM
REM PARAMETERS
REM 1. SQL_ID (required)
REM 2. Plan Hash Value for which a manual custom SQL Profile is
REM needed (required). A list of known plans is presented.
REM You may choose from list provided or enter a valid phv
REM from a version of the SQL modified with Hints.
REM
REM EXECUTION
REM 1. Connect into SQL*Plus as user with access to data dictionary.
REM Do not use SYS.
REM 2. Execute script coe_xfr_sql_profile.sql passing SQL_ID and
REM plan hash value (parameters can be passed inline or until
REM requested).
REM
REM EXAMPLE
REM # sqlplus system
REM SQL> START coe_xfr_sql_profile.sql [SQL_ID] [PLAN_HASH_VALUE];
REM SQL> START coe_xfr_sql_profile.sql gnjy0mn4y9pbm 2055843663;
REM SQL> START coe_xfr_sql_profile.sql gnjy0mn4y9pbm;
REM SQL> START coe_xfr_sql_profile.sql;
REM
REM NOTES
REM 1. For possible errors see coe_xfr_sql_profile.log
REM 2. If SQLT is installed in SOURCE, you can use instead:
REM sqlt/utl/sqltprofile.sql
REM 3. Be aware that using DBMS_SQLTUNE requires a license for
REM Oracle Tuning Pack.
REM 4. Use a DBA user but not SYS.
REM 5. If you get "ORA-06532: Subscript outside of limit, ORA-06512: at line 1"
REM Then you may consider this change (only in a test and disposable system):
REM create or replace TYPE sys.sqlprof_attr AS VARRAY(5000) of VARCHAR2(500);
REM
SET TERM ON ECHO OFF;
PRO
PRO Parameter 1:
PRO SQL_ID (required)
PRO
DEF sql_id = '&1';
PRO
WITH
p AS (
SELECT plan_hash_value
FROM gv$sql_plan
WHERE sql_id = TRIM('&&sql_id.')
AND other_xml IS NOT NULL
UNION
SELECT plan_hash_value
FROM dba_hist_sql_plan
WHERE sql_id = TRIM('&&sql_id.')
AND other_xml IS NOT NULL ),
m AS (
SELECT plan_hash_value,
SUM(elapsed_time)/SUM(executions) avg_et_secs
FROM gv$sql
WHERE sql_id = TRIM('&&sql_id.')
AND executions > 0
GROUP BY
plan_hash_value ),
a AS (
SELECT plan_hash_value,
SUM(elapsed_time_total)/SUM(executions_total) avg_et_secs
FROM dba_hist_sqlstat
WHERE sql_id = TRIM('&&sql_id.')
AND executions_total > 0
GROUP BY
plan_hash_value )
SELECT p.plan_hash_value,
ROUND(NVL(m.avg_et_secs, a.avg_et_secs)/1e6, 3) avg_et_secs
FROM p, m, a
WHERE p.plan_hash_value = m.plan_hash_value(+)
AND p.plan_hash_value = a.plan_hash_value(+)
ORDER BY
avg_et_secs NULLS LAST;
PRO
PRO Parameter 2:
PRO PLAN_HASH_VALUE (required)
PRO
DEF plan_hash_value = '&2';
PRO
PRO Values passed to coe_xfr_sql_profile:
PRO ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PRO SQL_ID : "&&sql_id."
PRO PLAN_HASH_VALUE: "&&plan_hash_value."
PRO
SET TERM OFF ECHO ON;
WHENEVER SQLERROR EXIT SQL.SQLCODE;
-- trim parameters
COL sql_id NEW_V sql_id FOR A30;
COL plan_hash_value NEW_V plan_hash_value FOR A30;
SELECT TRIM('&&sql_id.') sql_id, TRIM('&&plan_hash_value.') plan_hash_value FROM DUAL;
VAR sql_text CLOB;
VAR sql_text2 CLOB;
VAR other_xml CLOB;
EXEC :sql_text := NULL;
EXEC :sql_text2 := NULL;
EXEC :other_xml := NULL;
-- get sql_text from memory
DECLARE
l_sql_text VARCHAR2(32767);
BEGIN -- 10g see bug 5017909
FOR i IN (SELECT DISTINCT piece, sql_text
FROM gv$sqltext_with_newlines
WHERE sql_id = TRIM('&&sql_id.')
ORDER BY 1, 2)
LOOP
IF :sql_text IS NULL THEN
DBMS_LOB.CREATETEMPORARY(:sql_text, TRUE);
DBMS_LOB.OPEN(:sql_text, DBMS_LOB.LOB_READWRITE);
END IF;
-- removes NUL characters
l_sql_text := REPLACE(i.sql_text, CHR(00), ' ');
-- adds a NUL character at the end of each line
DBMS_LOB.WRITEAPPEND(:sql_text, LENGTH(l_sql_text) + 1, l_sql_text||CHR(00));
END LOOP;
-- if found in memory then sql_text is not null
IF :sql_text IS NOT NULL THEN
DBMS_LOB.CLOSE(:sql_text);
END IF;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('getting sql_text from memory: '||SQLERRM);
:sql_text := NULL;
END;
/
SELECT :sql_text FROM DUAL;
-- get sql_text from awr
DECLARE
l_sql_text VARCHAR2(32767);
l_clob_size NUMBER;
l_offset NUMBER;
BEGIN
IF :sql_text IS NULL OR NVL(DBMS_LOB.GETLENGTH(:sql_text), 0) = 0 THEN
SELECT sql_text
INTO :sql_text2
FROM dba_hist_sqltext
WHERE sql_id = TRIM('&&sql_id.')
AND sql_text IS NOT NULL
AND ROWNUM = 1;
END IF;
-- if found in awr then sql_text2 is not null
IF :sql_text2 IS NOT NULL THEN
l_clob_size := NVL(DBMS_LOB.GETLENGTH(:sql_text2), 0);
l_offset := 1;
DBMS_LOB.CREATETEMPORARY(:sql_text, TRUE);
DBMS_LOB.OPEN(:sql_text, DBMS_LOB.LOB_READWRITE);
-- store in clob as 64 character pieces plus a NUL character at the end of each piece
WHILE l_offset < l_clob_size
LOOP
IF l_clob_size - l_offset > 64 THEN
l_sql_text := REPLACE(DBMS_LOB.SUBSTR(:sql_text2, 64, l_offset), CHR(00), ' ');
ELSE -- last piece
l_sql_text := REPLACE(DBMS_LOB.SUBSTR(:sql_text2, l_clob_size - l_offset + 1, l_offset), CHR(00), ' ');
END IF;
DBMS_LOB.WRITEAPPEND(:sql_text, LENGTH(l_sql_text) + 1, l_sql_text||CHR(00));
l_offset := l_offset + 64;
END LOOP;
DBMS_LOB.CLOSE(:sql_text);
END IF;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('getting sql_text from awr: '||SQLERRM);
:sql_text := NULL;
END;
/
SELECT :sql_text2 FROM DUAL;
SELECT :sql_text FROM DUAL;
-- validate sql_text
SET TERM ON;
BEGIN
IF :sql_text IS NULL THEN
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).');
END IF;
END;
/
SET TERM OFF;
-- get other_xml from memory
BEGIN
FOR i IN (SELECT other_xml
FROM gv$sql_plan
WHERE sql_id = TRIM('&&sql_id.')
AND plan_hash_value = TO_NUMBER(TRIM('&&plan_hash_value.'))
AND other_xml IS NOT NULL
ORDER BY
child_number, id)
LOOP
:other_xml := i.other_xml;
EXIT; -- 1st
END LOOP;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('getting other_xml from memory: '||SQLERRM);
:other_xml := NULL;
END;
/
-- get other_xml from awr
BEGIN
IF :other_xml IS NULL OR NVL(DBMS_LOB.GETLENGTH(:other_xml), 0) = 0 THEN
FOR i IN (SELECT other_xml
FROM dba_hist_sql_plan
WHERE sql_id = TRIM('&&sql_id.')
AND plan_hash_value = TO_NUMBER(TRIM('&&plan_hash_value.'))
AND other_xml IS NOT NULL
ORDER BY
id)
LOOP
:other_xml := i.other_xml;
EXIT; -- 1st
END LOOP;
END IF;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('getting other_xml from awr: '||SQLERRM);
:other_xml := NULL;
END;
/
-- get other_xml from memory from modified SQL
BEGIN
IF :other_xml IS NULL OR NVL(DBMS_LOB.GETLENGTH(:other_xml), 0) = 0 THEN
FOR i IN (SELECT other_xml
FROM gv$sql_plan
WHERE plan_hash_value = TO_NUMBER(TRIM('&&plan_hash_value.'))
AND other_xml IS NOT NULL
ORDER BY
child_number, id)
LOOP
:other_xml := i.other_xml;
EXIT; -- 1st
END LOOP;
END IF;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('getting other_xml from memory: '||SQLERRM);
:other_xml := NULL;
END;
/
-- get other_xml from awr from modified SQL
BEGIN
IF :other_xml IS NULL OR NVL(DBMS_LOB.GETLENGTH(:other_xml), 0) = 0 THEN
FOR i IN (SELECT other_xml
FROM dba_hist_sql_plan
WHERE plan_hash_value = TO_NUMBER(TRIM('&&plan_hash_value.'))
AND other_xml IS NOT NULL
ORDER BY
id)
LOOP
:other_xml := i.other_xml;
EXIT; -- 1st
END LOOP;
END IF;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('getting other_xml from awr: '||SQLERRM);
:other_xml := NULL;
END;
/
SELECT :other_xml FROM DUAL;
-- validate other_xml
SET TERM ON;
BEGIN
IF :other_xml IS NULL THEN
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).');
END IF;
END;
/
SET TERM OFF;
-- generates script that creates sql profile in target system:
SET ECHO OFF;
PRO coe_xfr_sql_profile_&&sql_id._&&plan_hash_value..sql.
SET FEED OFF LIN 666 TRIMS ON TI OFF TIMI OFF SERVEROUT ON SIZE 1000000 FOR WOR;
SET SERVEROUT ON SIZE UNL FOR WOR;
SPO OFF;
SPO coe_xfr_sql_profile_&&sql_id._&&plan_hash_value..sql;
DECLARE
l_pos NUMBER;
l_clob_size NUMBER;
l_offset NUMBER;
l_sql_text VARCHAR2(32767);
l_len NUMBER;
l_hint VARCHAR2(32767);
BEGIN
DBMS_OUTPUT.PUT_LINE('SPO coe_xfr_sql_profile_&&sql_id._&&plan_hash_value..log;');
DBMS_OUTPUT.PUT_LINE('SET ECHO ON TERM ON LIN 2000 TRIMS ON NUMF 99999999999999999999;');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('REM $Header: 215187.1 coe_xfr_sql_profile_&&sql_id._&&plan_hash_value..sql 11.4.4.4 '||TO_CHAR(SYSDATE, 'YYYY/MM/DD')||' carlos.sierra $');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('REM Copyright (c) 2000-2012, Oracle Corporation. All rights reserved.');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('REM AUTHOR');
DBMS_OUTPUT.PUT_LINE('REM [email protected]');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('REM SCRIPT');
DBMS_OUTPUT.PUT_LINE('REM coe_xfr_sql_profile_&&sql_id._&&plan_hash_value..sql');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('REM DESCRIPTION');
DBMS_OUTPUT.PUT_LINE('REM This script is generated by coe_xfr_sql_profile.sql');
DBMS_OUTPUT.PUT_LINE('REM It contains the SQL*Plus commands to create a custom');
DBMS_OUTPUT.PUT_LINE('REM SQL Profile for SQL_ID &&sql_id. based on plan hash');
DBMS_OUTPUT.PUT_LINE('REM value &&plan_hash_value..');
DBMS_OUTPUT.PUT_LINE('REM The custom SQL Profile to be created by this script');
DBMS_OUTPUT.PUT_LINE('REM will affect plans for SQL commands with signature');
DBMS_OUTPUT.PUT_LINE('REM matching the one for SQL Text below.');
DBMS_OUTPUT.PUT_LINE('REM Review SQL Text and adjust accordingly.');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('REM PARAMETERS');
DBMS_OUTPUT.PUT_LINE('REM None.');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('REM EXAMPLE');
DBMS_OUTPUT.PUT_LINE('REM SQL> START coe_xfr_sql_profile_&&sql_id._&&plan_hash_value..sql;');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('REM NOTES');
DBMS_OUTPUT.PUT_LINE('REM 1. Should be run as SYSTEM or SYSDBA.');
DBMS_OUTPUT.PUT_LINE('REM 2. User must have CREATE ANY SQL PROFILE privilege.');
DBMS_OUTPUT.PUT_LINE('REM 3. SOURCE and TARGET systems can be the same or similar.');
DBMS_OUTPUT.PUT_LINE('REM 4. To drop this custom SQL Profile after it has been created:');
DBMS_OUTPUT.PUT_LINE('REM EXEC DBMS_SQLTUNE.DROP_SQL_PROFILE(''coe_&&sql_id._&&plan_hash_value.'');');
DBMS_OUTPUT.PUT_LINE('REM 5. Be aware that using DBMS_SQLTUNE requires a license');
DBMS_OUTPUT.PUT_LINE('REM for the Oracle Tuning Pack.');
DBMS_OUTPUT.PUT_LINE('REM 6. If you modified a SQL putting Hints in order to produce a desired');
DBMS_OUTPUT.PUT_LINE('REM Plan, you can remove the artifical Hints from SQL Text pieces below.');
DBMS_OUTPUT.PUT_LINE('REM By doing so you can create a custom SQL Profile for the original');
DBMS_OUTPUT.PUT_LINE('REM SQL but with the Plan captured from the modified SQL (with Hints).');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('WHENEVER SQLERROR EXIT SQL.SQLCODE;');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('VAR signature NUMBER;');
DBMS_OUTPUT.PUT_LINE('VAR signaturef NUMBER;');
DBMS_OUTPUT.PUT_LINE('REM');
DBMS_OUTPUT.PUT_LINE('DECLARE');
DBMS_OUTPUT.PUT_LINE('sql_txt CLOB;');
DBMS_OUTPUT.PUT_LINE('h SYS.SQLPROF_ATTR;');
DBMS_OUTPUT.PUT_LINE('PROCEDURE wa (p_line IN VARCHAR2) IS');
DBMS_OUTPUT.PUT_LINE('BEGIN');
DBMS_OUTPUT.PUT_LINE('DBMS_LOB.WRITEAPPEND(sql_txt, LENGTH(p_line), p_line);');
DBMS_OUTPUT.PUT_LINE('END wa;');
DBMS_OUTPUT.PUT_LINE('BEGIN');
DBMS_OUTPUT.PUT_LINE('DBMS_LOB.CREATETEMPORARY(sql_txt, TRUE);');
DBMS_OUTPUT.PUT_LINE('DBMS_LOB.OPEN(sql_txt, DBMS_LOB.LOB_READWRITE);');
DBMS_OUTPUT.PUT_LINE('-- SQL Text pieces below do not have to be of same length.');
DBMS_OUTPUT.PUT_LINE('-- So if you edit SQL Text (i.e. removing temporary Hints),');
DBMS_OUTPUT.PUT_LINE('-- there is no need to edit or re-align unmodified pieces.');
l_clob_size := NVL(DBMS_LOB.GETLENGTH(:sql_text), 0);
l_offset := 1;
WHILE l_offset < l_clob_size
LOOP
l_pos := DBMS_LOB.INSTR(:sql_text, CHR(00), l_offset);
IF l_pos > 0 THEN
l_len := l_pos - l_offset;
ELSE -- last piece
l_len := l_clob_size - l_pos + 1;
END IF;
l_sql_text := DBMS_LOB.SUBSTR(:sql_text, l_len, l_offset);
/* cannot do such 3 replacement since a line could end with a comment using "--"
l_sql_text := REPLACE(l_sql_text, CHR(10), ' '); -- replace LF with SP
l_sql_text := REPLACE(l_sql_text, CHR(13), ' '); -- replace CR with SP
l_sql_text := REPLACE(l_sql_text, CHR(09), ' '); -- replace TAB with SP
*/
l_offset := l_offset + l_len + 1;
IF l_len > 0 THEN
IF INSTR(l_sql_text, '''[') + INSTR(l_sql_text, ']''') = 0 THEN
l_sql_text := '['||l_sql_text||']';
ELSIF INSTR(l_sql_text, '''{') + INSTR(l_sql_text, '}''') = 0 THEN
l_sql_text := '{'||l_sql_text||'}';
ELSIF INSTR(l_sql_text, '''<') + INSTR(l_sql_text, '>''') = 0 THEN
l_sql_text := '<'||l_sql_text||'>';
ELSIF INSTR(l_sql_text, '''(') + INSTR(l_sql_text, ')''') = 0 THEN
l_sql_text := '('||l_sql_text||')';
ELSIF INSTR(l_sql_text, '''"') + INSTR(l_sql_text, '"''') = 0 THEN
l_sql_text := '"'||l_sql_text||'"';
ELSIF INSTR(l_sql_text, '''|') + INSTR(l_sql_text, '|''') = 0 THEN
l_sql_text := '|'||l_sql_text||'|';
ELSIF INSTR(l_sql_text, '''~') + INSTR(l_sql_text, '~''') = 0 THEN
l_sql_text := '~'||l_sql_text||'~';
ELSIF INSTR(l_sql_text, '''^') + INSTR(l_sql_text, '^''') = 0 THEN
l_sql_text := '^'||l_sql_text||'^';
ELSIF INSTR(l_sql_text, '''@') + INSTR(l_sql_text, '@''') = 0 THEN
l_sql_text := '@'||l_sql_text||'@';
ELSIF INSTR(l_sql_text, '''#') + INSTR(l_sql_text, '#''') = 0 THEN
l_sql_text := '#'||l_sql_text||'#';
ELSIF INSTR(l_sql_text, '''%') + INSTR(l_sql_text, '%''') = 0 THEN
l_sql_text := '%'||l_sql_text||'%';
ELSIF INSTR(l_sql_text, '''$') + INSTR(l_sql_text, '$''') = 0 THEN
l_sql_text := '$'||l_sql_text||'$';
ELSE
l_sql_text := CHR(96)||l_sql_text||CHR(96);
END IF;
DBMS_OUTPUT.PUT_LINE('wa(q'''||l_sql_text||''');');
END IF;
END LOOP;
DBMS_OUTPUT.PUT_LINE('DBMS_LOB.CLOSE(sql_txt);');
DBMS_OUTPUT.PUT_LINE('h := SYS.SQLPROF_ATTR(');
DBMS_OUTPUT.PUT_LINE('q''[BEGIN_OUTLINE_DATA]'',');
FOR i IN (SELECT /*+ opt_param('parallel_execution_enabled', 'false') */
SUBSTR(EXTRACTVALUE(VALUE(d), '/hint'), 1, 4000) hint
FROM TABLE(XMLSEQUENCE(EXTRACT(XMLTYPE(:other_xml), '/*/outline_data/hint'))) d)
LOOP
l_hint := i.hint;
WHILE NVL(LENGTH(l_hint), 0) > 0
LOOP
IF LENGTH(l_hint) <= 500 THEN
DBMS_OUTPUT.PUT_LINE('q''['||l_hint||']'',');
l_hint := NULL;
ELSE
l_pos := INSTR(SUBSTR(l_hint, 1, 500), ' ', -1);
DBMS_OUTPUT.PUT_LINE('q''['||SUBSTR(l_hint, 1, l_pos)||']'',');
l_hint := ' '||SUBSTR(l_hint, l_pos);
END IF;
END LOOP;
END LOOP;
DBMS_OUTPUT.PUT_LINE('q''[END_OUTLINE_DATA]'');');
DBMS_OUTPUT.PUT_LINE(':signature := DBMS_SQLTUNE.SQLTEXT_TO_SIGNATURE(sql_txt);');
DBMS_OUTPUT.PUT_LINE(':signaturef := DBMS_SQLTUNE.SQLTEXT_TO_SIGNATURE(sql_txt, TRUE);');
DBMS_OUTPUT.PUT_LINE('DBMS_SQLTUNE.IMPORT_SQL_PROFILE (');
DBMS_OUTPUT.PUT_LINE('sql_text => sql_txt,');
DBMS_OUTPUT.PUT_LINE('profile => h,');
DBMS_OUTPUT.PUT_LINE('name => ''coe_&&sql_id._&&plan_hash_value.'',');
DBMS_OUTPUT.PUT_LINE('description => ''coe &&sql_id. &&plan_hash_value. ''||:signature||'' ''||:signaturef||'''',');
DBMS_OUTPUT.PUT_LINE('category => ''DEFAULT'',');
DBMS_OUTPUT.PUT_LINE('validate => TRUE,');
DBMS_OUTPUT.PUT_LINE('replace => TRUE,');
DBMS_OUTPUT.PUT_LINE('force_match => FALSE /* TRUE:FORCE (match even when different literals in SQL). FALSE:EXACT (similar to CURSOR_SHARING) */ );');
DBMS_OUTPUT.PUT_LINE('DBMS_LOB.FREETEMPORARY(sql_txt);');
DBMS_OUTPUT.PUT_LINE('END;');
DBMS_OUTPUT.PUT_LINE('/');
DBMS_OUTPUT.PUT_LINE('WHENEVER SQLERROR CONTINUE');
DBMS_OUTPUT.PUT_LINE('SET ECHO OFF;');
DBMS_OUTPUT.PUT_LINE('PRINT signature');
DBMS_OUTPUT.PUT_LINE('PRINT signaturef');
DBMS_OUTPUT.PUT_LINE('PRO');
DBMS_OUTPUT.PUT_LINE('PRO ... manual custom SQL Profile has been created');
DBMS_OUTPUT.PUT_LINE('PRO');
DBMS_OUTPUT.PUT_LINE('SET TERM ON ECHO OFF LIN 80 TRIMS OFF NUMF "";');
DBMS_OUTPUT.PUT_LINE('SPO OFF;');
DBMS_OUTPUT.PUT_LINE('PRO');
DBMS_OUTPUT.PUT_LINE('PRO COE_XFR_SQL_PROFILE_&&sql_id._&&plan_hash_value. completed');
END;
/
SPO OFF;
SET DEF ON TERM ON ECHO OFF FEED 6 VER ON HEA ON LIN 80 PAGES 14 LONG 80 LONGC 80 TRIMS OFF TI OFF TIMI OFF SERVEROUT OFF NUMF "" SQLP SQL>;
SET SERVEROUT OFF;
PRO
PRO Execute coe_xfr_sql_profile_&&sql_id._&&plan_hash_value..sql
PRO on TARGET system in order to create a custom SQL Profile
PRO with plan &&plan_hash_value linked to adjusted sql_text.
PRO
UNDEFINE 1 2 sql_id plan_hash_value
CL COL
PRO
PRO COE_XFR_SQL_PROFILE completed.
SQL> @coe_xfr_sql_profile.sql
Parameter 1:
SQL_ID (required)
?? 1 μ?μ: 0n82d9qnjxhxv
PLAN_HASH_VALUE AVG_ET_SECS
--------------- -----------
1483576328 .963
1285018022 963.461
Parameter 2:
PLAN_HASH_VALUE (required)
输入 2 的值: 1483576328
Values passed to coe_xfr_sql_profile:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
SQL_ID : "0n82d9qnjxhxv"
PLAN_HASH_VALUE: "1483576328"
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;
4之后再次查看表当前统计信息,进行验证
select owner, table_name, num_rows, blocks, avg_row_len, partitioned, to_char(last_analyzed, 'YYYY-MM-DD HH24:MI:SS')
from dba_tables
where owner ='用户名’
and table_name in ('表名');
3.2 问题分析总结
- 综合上述分析,我们可以看到:本次问题出现的原因一个是Oracle周末自动收集统计信息的时间正好在表清数之后,发生巧合导致执行计划发生改变,还有一点是业务对表进行大量的增删改操作后发现前后数据量没有什么区别,所以认为数据量变化不大对问题处理造成误导,在大批量量的增删改操作后应对表进行统计信息的收集工作。
4. 处理/优化建议
- 除了该表外,自动的收集统计信息任务是对全数据库进行的,还需要查看该库下其他表是否也存在执行计划改变的情况。
- 加强协作,和业务人员进行有效的交流沟通,明确跑批都进行了什么操作,并且建议业务人员在之后对表进行大量的增删改操作后及时收集统计信息,更新执行计划。