PLSQL_统计信息系列10_统计信息过旧导致程序出现性能问题
2014-11-15 Created By BaoXinjian
一、摘要
在性能的稳定数据库中，所有的job都需要在一定时间内完成
以前在一个银行系统中，突然某一个job原本在30minutes内完成的，但是在3hours之后，还在运行
排除了数据量大小变化的影响，需要查看该程序的解析计划是否变更，在稳定的系统中，job对应的explain plan一般通过sqlplan management固定，很少变化
所以需要查看，是否job对应的sqlplan explain是否变化
一般来说，解析计划变更也会导致此类问题
二、解决方式
Step1. 查看程序对应的session
select sid, sql_id from v$session where sid = 1001
Step2. 查看该长时间运行sql对应的解析计划是否在这段时间有过变更
select b.begin_interval_time,
a.disk_reads_total,
a.buffer_gets_total,
a.buffer_gets_delta,
a.rows_processed_total,
a.plan_hash_value
from dba_hist_sqlstat a, dba_hist_snapshot b
where a.snap_id = b.snap_id
and sql_id = '466bpq7055f4c'
order by 1 desc;
Step3. 查看对应session目前在运行的sql text
select* from v$sql_plan
Step4. 查看表的统计时间
select name, last_analized from dba_tables
Step5. 对表进行产生统计信息
exec dbms_stats.gather_table_stats(
ownname=>'SCOT',
tabname=>'GAVIN',
estimate_percent=>3,
degree=>32,
granularity=>'GLOBAL',
cascade=>FALSE,
no_invalidate=>FALSE);
Step6. 该sql_id所对应的执行时间和次数
SELECT DBMS_LOB.SUBSTR (sql_text, 100, 1) SQL_SHORT,
tab1.sql_id,
DBMS_LOB.getlength (sql_text) SQL_Len,
ROUND (TOTAL_WAIT / 1000000, 2) TOTAL_WAIT_SECS,
ROUND (ELAPSED_TIME_DELTA / 1000000, 2) TOTAL_TIME_SECS,
TO_CHAR (BEGIN_INTERVAL_TIME, 'DAY', 'NLS_DATE_LANGUAGE=AMERICAN')
Week_Day,
BEGIN_INTERVAL_TIME,
END_INTERVAL_TIME,
EXEC_COUNT,
AVG_CPU_TIME_SECS,
AVG_ELAPSED_SECS,
ROUND (ELAPSED_TIME_DELTA / 1000000, 0) ELAPSED_TIME_DELTA,
ROUND (AVG_ROWS_PROCESSED, 1) AVG_ROWS_PROCESSED,
PLAN_HASH_VALUE,
MODULE,
ACTION,
PARSING_SCHEMA_NAME,
(SELECT username
FROM dba_users
WHERE user_id = PARSING_USER_ID)
PARSING_USER,
AVG_BUFFER_GETS,
AVG_DISK_READS,
AVG_IOWAIT AVG_iowai_secs,
AVG_CCWAIT AVG_ccwait_secs,
AVG_CLWAIT AVG_clwait_secs,
AVG_APWAIT AVG_apwait_secs,
AVG_PX_SERVERS,
AVG_PARSE_CALLS,
tab1.SNAP_ID,
tab1.INSTANCE_NUMBER,
AVG_CELL_UNCOMPRESSED_BYTES,
AVG_DIRECT_WRITES,
AVG_IO_INTERCONNECT_BYTES,
AVG_IO_OFFLOAD_ELIG_BYTES,
AVG_IO_OFFLOAD_RETURN_BYTES,
AVG_JAVEXEC_TIME,
AVG_OPTIMIZED_PHYSICAL_READS,
AVG_PLSEXEC_TIME_DELTA,
AVG_SORTS_DELTA,
-- BIND_DATA, -- -- (Falta arreglar) listagg( (select * from table(dbms_sqltune.extract_binds(bind_data)), '#') WITHIN GROUP (ORDER BY 1)) Binds ,
DBMS_LOB.SUBSTR (sql_text, 2000, 1) SQL_TEXT1,
DBMS_LOB.SUBSTR (sql_text, 2000, 2001) SQL_TEXT2,
DBMS_LOB.SUBSTR (sql_text, 2000, 4001) SQL_TEXT3,
DBMS_LOB.SUBSTR (sql_text, 2000, 6001) SQL_TEXT4,
DBMS_LOB.SUBSTR (sql_text, 2000, 8001) SQL_TEXT5,
DBMS_LOB.SUBSTR (sql_text, 2000, 10001) SQL_TEXT6,
DBMS_LOB.SUBSTR (sql_text, 2000, 12001) SQL_TEXT7,
DBMS_LOB.SUBSTR (sql_text, 2000, 14001) SQL_TEXT8,
DBMS_LOB.SUBSTR (sql_text, 2000, 16001) SQL_TEXT9,
DBMS_LOB.SUBSTR (sql_text, 2000, 18001) SQL_TEXT10
FROM DBA_HIST_SQLTEXT D,
DBA_HIST_SNAPSHOT N,
( SELECT S.SQL_ID SQL_ID,
instance_number,
SUM (EXECUTIONS) EXEC_COUNT,
ROUND ( (SUM (CPU_TIME_DELTA) / SUM (EXECUTIONS)) / 1000000,
4)
AVG_CPU_TIME_SECS,
ROUND (
(SUM (ELAPSED_TIME_DELTA) / SUM (EXECUTIONS)) / 1000000,
4)
AVG_ELAPSED_SECS,
SUM (ELAPSED_TIME_DELTA) ELAPSED_TIME_DELTA,
ROUND ( (SUM (ROWS_PROCESSED_DELTA) / SUM (EXECUTIONS)), 4)
AVG_ROWS_PROCESSED,
PLAN_HASH_VALUE,
MODULE,
ACTION,
PARSING_SCHEMA_NAME,
PARSING_USER_ID,
ROUND (SUM (BUFFER_GETS_DELTA) / SUM (EXECUTIONS), 4)
AVG_BUFFER_GETS,
ROUND (SUM (DISK_READS_DELTA) / SUM (EXECUTIONS), 0)
AVG_DISK_READS,
SNAP_ID,
ROUND ( (SUM (IOWAIT_DELTA) / SUM (EXECUTIONS)) / 1000000, 4)
AVG_IOWAIT,
ROUND ( (SUM (CCWAIT_DELTA) / SUM (EXECUTIONS)) / 1000000, 4)
AVG_CCWAIT,
ROUND ( (SUM (CLWAIT_DELTA) / SUM (EXECUTIONS)) / 1000000, 4)
AVG_CLWAIT,
ROUND ( (SUM (APWAIT_DELTA) / SUM (EXECUTIONS)) / 1000000, 4)
AVG_APWAIT,
ROUND (SUM (PX_SERVERS_EXECS_DELTA) / SUM (EXECUTIONS), 4)
AVG_PX_SERVERS,
ROUND (SUM (PARSE_CALLS_DELTA) / SUM (EXECUTIONS), 4)
AVG_PARSE_CALLS,
ROUND (SUM (CELL_UNCOMPRESSED_BYTES_DELTA) / SUM (EXECUTIONS),
4)
AVG_CELL_UNCOMPRESSED_BYTES,
ROUND (SUM (DIRECT_WRITES_DELTA) / SUM (EXECUTIONS), 4)
AVG_DIRECT_WRITES,
ROUND (SUM (IO_INTERCONNECT_BYTES_DELTA) / SUM (EXECUTIONS),
4)
AVG_IO_INTERCONNECT_BYTES,
ROUND (SUM (IO_OFFLOAD_ELIG_BYTES_DELTA) / SUM (EXECUTIONS),
4)
AVG_IO_OFFLOAD_ELIG_BYTES,
ROUND (SUM (IO_OFFLOAD_RETURN_BYTES_DELTA) / SUM (EXECUTIONS),
4)
AVG_IO_OFFLOAD_RETURN_BYTES,
ROUND (SUM (JAVEXEC_TIME_DELTA) / SUM (EXECUTIONS), 4)
AVG_JAVEXEC_TIME,
ROUND (
SUM (OPTIMIZED_PHYSICAL_READS_DELTA) / SUM (EXECUTIONS),
4)
AVG_OPTIMIZED_PHYSICAL_READS,
ROUND (SUM (PLSEXEC_TIME_DELTA) / SUM (EXECUTIONS), 4)
AVG_PLSEXEC_TIME_DELTA,
ROUND (SUM (SORTS_DELTA) / SUM (EXECUTIONS), 4)
AVG_SORTS_DELTA,
SUM (
IOWAIT_DELTA + CCWAIT_DELTA + CLWAIT_DELTA + APWAIT_DELTA)
TOTAL_WAIT,
MAX (BIND_DATA) BIND_DATA
FROM (SELECT S.*,
DECODE (EXECUTIONs_DELTA, 0, 1, EXECUTIONS_DELTA)
EXECUTIONS
FROM DBA_HIST_SQLSTAT S) S
WHERE 1 = 1 -- and ( PARSING_SCHEMA_NAME like 'EUS%' ) -- Filter by schema name
GROUP BY S.SQL_ID,
instance_number,
S.SNAP_ID,
PLAN_HASH_VALUE,
MODULE,
ACTION,
PARSING_SCHEMA_NAME,
S.INSTANCE_NUMBER,
PARSING_USER_ID
HAVING ROUND (
(SUM (ELAPSED_TIME_DELTA) / SUM (EXECUTIONS)) / 1000000,
4) >= 10 -- Filter >= n secs
ORDER BY 5 DESC) TAB1
WHERE D.SQL_ID = TAB1.SQL_ID AND TAB1.snap_id = N.snap_id -- and upper(tab1.module) like '%PKG_BATCH_PROCESSES_SDM%'
AND d.sql_id IN ('6tmcqrydfgdtc') -- AND D.SQL_ID in ( select distinct sql_id from DBA_HIST_ACTIVE_SESS_HISTORY where top_level_sql_id = '85xkhugz5kt8h' )
-- AND upper(DBMS_LOB.SUBSTR (sql_text, 100, 1)) LIKE 'INSERT%'
-- AND upper(DBMS_LOB.SUBSTR (sql_text, 1000, 1)) LIKE 'SELECT%'
-- AND upper(DBMS_LOB.SUBSTR (sql_text, 3000, 1)) LIKE '%INACTIVE%'
AND BEGIN_INTERVAL_TIME > SYSDATE - 60
-- and BEGIN_INTERVAL_TIME between to_date('05/09/2013 07:50:00', 'DD/MM/YYYY hh24:mi:ss') AND to_date('05/09/2013 16:10:00', 'DD/MM/YYYY hh24:mi:ss')
-- and BEGIN_INTERVAL_TIME >= (SELECT job_start_datetime - (2/24) FROM job_status WHERE job_name = 'RAVLDBSK' AND cob_date = (SELECT current_cob_date FROM eus_cob))
-- and BEGIN_INTERVAL_TIME <= (SELECT job_end_datetime + (2/24) FROM job_status WHERE job_name = 'RAVLDBSK' AND cob_date = (SELECT current_cob_date FROM eus_cob))
-- order by AVG_ELAPSED_SECS DESC
-- order by ELAPSED_TIME_DELTA DESC
ORDER BY BEGIN_INTERVAL_TIME DESC
-- order by TOTAL_WAIT_SECS desc；
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