Direct path write temp wait problrm
Hi there,
(DB= 11.2.0, OS= OL 5)
I have a query which it takes approximately 20 seconds if I run it manually against the server via a tool like PL/SQL Developer and takes about 7 minutes if it runs via a reporting tool like BI Publisher. I dont have this problem with other queries. the query is against a huge table containing 800 million records. through monitoring EM the problem seems to be the wait event "DIRECT PATH WRITE TEMP". But when I execute it manually that will not be an issue. I'm sure the queries are the same in both environments. Application Server (where the BIP runs on it) access to DB server is through a LAN and my access is through a VPN over the net. By the way, the query has no order by clause. The memory_target_parameter is 20g and sort_area_size is 65536.
Please help me to understand why two behaviors of DB against a same query and why the wait event "DIRECT PATH WRITE TEMP" occurs and how I can resolve it.
THANKS
SMSK
Thanks Dom,
After posting this thread I also doubted about different Plans, Too. I noticed that the application runs the query via a web service but there is no web service call when I run it on my PL/SQL Developer client. I dont know if this is informational or not.
Another thing that surprised me is DATABASE LINK. when I run a query containing a reference to a DB-LINK provided table, COMMIT and ROLLBACK buttons of the PL/SQL Developer client menu bar will be enabled. this is not natural. I just run a SELECT statement which doesnt require COMMIT nor ROLLBACK. So I try to temporarily bring those DB-LINK tables using CTAS. Surprisingly performance of the application server becomes good and prepares the report result in just 4 seconds!
Therefore, it seems that subject of the problem I'm looking for should be change to:
Why commit or rollback will be enabled after executing a select statement over a DB-LINK table?
IS this occurrence affects query performance?
Does this leads to wait event "direct path write temp"?
Any helpful comment or link about db-link performance.
SMSK.
Similar Messages
-
DIRECT PATH WRITE TEMP during SQL
Hi all,
recently I have been experiencing a very interesting question. We have 2 equal system therefore 2 databases. They have same hardware, the same memory and init configuration. On one of the system an SQL statement runs in 1 second, on the other system the statement hangs with:DIRECT PATH WRITE TEMP wait event. I came to the conclusion in a way that I traced the session:
*** 2013-08-08 18:09:05.131
*** SESSION ID:(90.36255) 2013-08-08 18:09:05.131
*** CLIENT ID:() 2013-08-08 18:09:05.131
*** SERVICE NAME:(SYS$USERS) 2013-08-08 18:09:05.131
*** MODULE NAME:(sqlplus@i87345 (TNS V1-V3)) 2013-08-08 18:09:05.131
*** ACTION NAME:() 2013-08-08 18:09:05.131
WAIT #140650920871104: nam='direct path write temp' ela= 2254 file number=201 first dba=1800095 block cnt=31 obj#=71542 tim=1375978145131322
*** 2013-08-08 18:09:25.905
WAIT #140650920871104: nam='direct path write temp' ela= 18683 file number=201 first dba=1746847 block cnt=31 obj#=71542 tim=1375978165905262
WAIT #140650920871104: nam='direct path write temp' ela= 26832 file number=201 first dba=1740253 block cnt=31 obj#=71542 tim=1375978165988243
and so on
just waiting and waiting, and then
ORA-01652: unable to extend temp segment by 128 in tablespace TEMP
significantly there is no difference in the amount of data between the 2 systems. Statistics have beeen collecting and are actual. Earlier the statement run properly, also within one second. Something has changed, but not to system configuration. Temp tablespace could be extended, but probably this is not the way (I think).
Any tip how we can continue?
thanks
AttilaRun both queries again, and pull the execution plans from memory using dbms_xplan.display_cursor() and the format 'peeked_binds' option.
Bear in mind that even if the data is the same, and stats were collected at the same instant on the two systems, a sample (rather than a compute) could result in slightly different statistics that end up giving different execution plans. This is more likely to happen if there are histograms on the critical columns.
Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
Now on Twitter: @jloracle -
Getting wait event "direct path write temp" during query execution
Hi All,
While executing one query in database, it is taking longer time and failing with error "ORA-01652: unable to extend temp segment by 1280 in tablespace PSTEMP".
I have increaesd the Temp tablespace size also till 96GB, Database size is 120GB.
I have upgraded the database from 10.2.0.3 to 11.2.0.3 version last month.
same query is running fine in other databases on same version.
It is giving me "Direct write temp path" wait event.
server load is also normal.
I have increased pga_aggregate_target upto 512MB but it has not solved my problem
Can you please help me out to solve this issue.Hi Nicolay,
Please find below output from that query :
SQL>
SELECT DBMS_SQLTUNE.report_sql_monitor(
sql_id => '(*******',
type => 'TEXT',
report_level => 'ALL') AS report
FROM dual;SQL> 2 3 4 5
SQL Monitoring Report
SQL Text
SELECT ASGN.TRANSACTIONID ,ASGN.UPA_CLIENT_ID FROM PS_UPA_CM_PRE_ASGN ASGN ,PS_UPA_CLIENT_TBL CL ,PS_UPA_CM_ADMIN_WL WL ,PSXLATITEM XCT ,PSXLATITEM XCS ,PS_PWC_INDUSTR_TBL IND ,PS_PWC_SUBIND_TBL SCT ,PS_UPA_FIN_REG_TBL REG ,PS_UPA_CM_MKT_VW1 MKT WHERE ASGN.UPA_CLIENT_ID = CL.UPA_CLIENT_ID AND CL.UPA_CM_GRP_ID = ' ' AND ASGN.UPA_CM_ADMIN_ACT = 'RCD' AND ASGN.UPA_CM_CLT_ROLENBR = WL.UPA_CM_CLT_ROLENBR AND ASGN.UPA_CM_ROLENBR_SEQ = WL.UPA_CM_ROLENBR_SEQ AND WL.UPA_CM_WL_STATUS = 'A' AND
WL.UPA_CM_ADMIN_ACT = 'RCD' AND CL.EFFDT = ( SELECT MAX(CL1.EFFDT) FROM PS_UPA_CLIENT_TBL CL1 WHERE CL1.UPA_CLIENT_ID = CL.UPA_CLIENT_ID AND CL1.EFFDT <= SYSDATE) AND CL.EFF_STATUS = 'A' AND CL.UPA_MONTH_DAY <> ' ' AND CL.UPA_CLIENT_TYPE <> ' ' AND CL.UPA_CLIENT_SEGMENT <> ' ' AND CL.PWC_INDUSTRY <> ' ' AND CL.PWC_SUB_INDUSTRY <> ' ' AND CL.UPA_FIN_REGION <> ' ' AND CL.UPA_STRAT_MKT <> ' ' AND CL.UPA_CLT_PRIORITIZ <> ' ' /*Harieash - Aadded as part of PR support IR 43024 */ AND XCT.FIELDNAME =
'UPA_CLIENT_TYPE' AND XCT.FIELDVALUE = CL.UPA_CLIENT_TYPE AND XCT.EFFDT = ( SELECT MAX(XCT1.EFFDT) FROM PSXLATITEM XCT1 WHERE XCT1.FIELDNAME = XCT.FIELDNAME AND XCT1.FIELDVALUE = XCT.FIELDVALUE AND XCT1.EFFDT <= SYSDATE) AND XCT.EFF_STATUS = 'A' AND XCS.FIELDNAME = 'UPA_CLIENT_SEGMENT' AND XCS.FIELDVALUE = CL.UPA_CLIENT_SEGMENT AND XCS.EFFDT = ( SELECT MAX(XCS1.EFFDT) FROM PSXLATITEM XCS1 WHERE XCS1.FIELDNAME = XCS.FIELDNAME AND XCS1.FIELDVALUE = XCS.FIELDVALUE AND XCS1.EFFDT <= SYSDATE) AND
XCS.EFF_STATUS = 'A' AND IND.SETID = 'USA00' AND CL.PWC_INDUSTRY = IND.PWC_INDUSTRY AND IND.EFFDT = ( SELECT MAX(IND1.EFFDT) FROM PS_PWC_INDUSTR_TBL IND1 WHERE IND1.SETID = IND.SETID AND IND1.PWC_INDUSTRY = IND.PWC_INDUSTRY AND IND1.EFFDT <= SYSDATE) AND IND.EFF_STATUS = 'A' AND SCT.SETID = 'USA00' AND CL.PWC_SUB_INDUSTRY = SCT.PWC_SUB_INDUSTRY AND SCT.EFFDT = ( SELECT MAX(SCT1.EFFDT) FROM PS_PWC_SUBIND_TBL SCT1 WHERE SCT1.SETID = SCT.SETID AND SCT1.PWC_SUB_INDUSTRY = SCT.PWC_SUB_INDUSTRY AND
SCT1.EFFDT <= SYSDATE) AND SCT.EFF_STATUS = 'A' AND REG.SETID = 'USA00' AND CL.UPA_FIN_REGION = REG.UPA_FIN_REGION AND REG.EFFDT = ( SELECT MAX(REG1.EFFDT) FROM PS_UPA_FIN_REG_TBL REG1 WHERE REG1.SETID = 'USA00' AND REG1.UPA_FIN_REGION = REG.UPA_FIN_REGION AND REG1.EFFDT <= SYSDATE) AND REG.EFF_STATUS = 'A' AND CL.UPA_STRAT_MKT = MKT.UPA_STRAT_MKT
Global Information
Status : EXECUTING
Instance ID : 1
Session : *******
SQL ID : *******
SQL Execution ID : *********
Execution Started : 11/12/2012 04:31:25
First Refresh Time : 11/12/2012 04:31:33
Last Refresh Time : 11/12/2012 04:31:55
Duration : 31s
Module/Action : ***** (TNS V1-V3)/-
Service : SYS$USERS
Program : ******* (TNS V1-V3)
Global Stats
=========================================================
| Elapsed | Cpu | IO | Buffer | Write | Write |
| Time(s) | Time(s) | Waits(s) | Gets | Reqs | Bytes |
=========================================================
| 33 | 25 | 7.30 | 162 | 4755 | 557MB |
=========================================================
SQL Plan Monitoring Details (Plan Hash Value=2177602723)
========================================================================================================================================================================================================
| Id | Operation | Name | Rows | Cost | Time | Start | Execs | Rows | Write | Write | Mem | Temp | Activity | Activity Detail |
| | | | (Estim) | | Active(s) | Active | | (Actual) | Reqs | Bytes | | | (%) | (# samples) |
========================================================================================================================================================================================================
| 0 | SELECT STATEMENT | | | | | | 1 | | | | | | | |
| 1 | NESTED LOOPS | | | | | | 1 | | | | | | | |
| 2 | NESTED LOOPS | | 1 | 491 | | | 1 | | | | | | | |
| -> 3 | HASH JOIN | | 120 | 130 | 31 | +1 | 1 | 0 | 4011 | 470MB | 95M | 598M | 80.65 | Cpu (19) |
| | | | | | | | | | | | | | | direct path write temp (6) |
| -> 4 | MERGE JOIN CARTESIAN | | 120 | 61 | 23 | +8 | 1 | 13M | | | | | | |
| -> 5 | MERGE JOIN CARTESIAN | | 1 | 38 | 23 | +8 | 1 | 1870 | | | | | | |
| -> 6 | MERGE JOIN CARTESIAN | | 1 | 37 | 23 | +8 | 1 | 70 | | | | | | |
| -> 7 | MERGE JOIN CARTESIAN | | 1 | 35 | 23 | +8 | 1 | 12 | | | | | | |
| 8 | MERGE JOIN CARTESIAN | | 1 | 33 | 21 | +8 | 1 | 2 | | | | | | |
| 9 | MERGE JOIN CARTESIAN | | 1 | 31 | 1 | +8 | 1 | 1 | | | | | | |
| 10 | VIEW | PS_UPA_CM_MKT_VW1 | 1 | 29 | 1 | +8 | 1 | 1 | | | | | | |
| 11 | SORT UNIQUE | | 1 | 28 | 1 | +8 | 1 | 1 | | | | | | |
| 12 | TABLE ACCESS BY INDEX ROWID | PS_UPA_ST_MKT_TBL | 10 | 2 | 1 | +8 | 1 | 43 | | | | | | |
| 13 | INDEX SKIP SCAN | PS0UPA_ST_MKT_TBL | 10 | 1 | 1 | +8 | 1 | 43 | | | | | | |
| 14 | SORT AGGREGATE | | 1 | | 1 | +8 | 33 | 33 | | | | | | |
| 15 | INDEX SKIP SCAN | PS0UPA_ST_MKT_TBL | 2 | 1 | 1 | +8 | 33 | 50 | | | | | | |
| 16 | BUFFER SORT | | 1 | 31 | 1 | +8 | 1 | 1 | | | | | | |
| 17 | TABLE ACCESS BY INDEX ROWID | PSXLATITEM | 1 | 2 | 1 | +8 | 1 | 14 | | | | | | |
| 18 | INDEX RANGE SCAN | PS_PSXLATITEM | 1 | 1 | 1 | +8 | 1 | 14 | | | | | | |
| 19 | SORT AGGREGATE | | 1 | | 1 | +8 | 14 | 14 | | | | | | |
| 20 | INDEX RANGE SCAN | PS_PSXLATITEM | 1 | 1 | 1 | +8 | 14 | 14 | | | | | | |
| 21 | BUFFER SORT | | 1 | 31 | 21 | +8 | 1 | 2 | | | | | | |
| 22 | TABLE ACCESS BY INDEX ROWID | PSXLATITEM | 1 | 2 | 1 | +8 | 1 | 2 | | | | | | |
| 23 | INDEX RANGE SCAN | PS_PSXLATITEM | 1 | 1 | 1 | +8 | 1 | 2 | | | | | | |
| 24 | SORT AGGREGATE | | 1 | | 1 | +8 | 2 | 2 | | | | | | |
| 25 | INDEX RANGE SCAN | PS_PSXLATITEM | 1 | 1 | 1 | +8 | 2 | 2 | | | | | | |
| -> 26 | BUFFER SORT | | 3 | 33 | 23 | +8 | 2 | 12 | | | | | | |
| 27 | TABLE ACCESS BY INDEX ROWID | PS_PWC_INDUSTR_TBL | 3 | 2 | 1 | +8 | 1 | 10 | | | | | | |
| 28 | INDEX SKIP SCAN | PS0PWC_INDUSTR_TBL | 6 | 1 | 1 | +8 | 1 | 26 | | | | | | |
| 29 | SORT AGGREGATE | | 1 | | 1 | +8 | 26 | 26 | | | | | | |
| 30 | FIRST ROW | | 1 | 1 | 1 | +8 | 26 | 26 | | | | | | |
| -> 31 | INDEX RANGE SCAN (MIN/MAX) | PS_PWC_INDUSTR_TBL | 1 | 1 | 23 | +8 | 26 | 26 | | | | | | |
| -> 32 | BUFFER SORT | | 3 | 35 | 23 | +8 | 12 | 70 | | | | | | |
| 33 | TABLE ACCESS BY INDEX ROWID | PS_UPA_FIN_REG_TBL | 3 | 2 | 1 | +8 | 1 | 6 | | | | | | |
| 34 | INDEX SKIP SCAN | PS0UPA_FIN_REG_TBL | 6 | 1 | 1 | +8 | 1 | 12 | | | | | | |
| 35 | SORT AGGREGATE | | 1 | | 1 | +8 | 12 | 12 | | | | | | |
| 36 | FIRST ROW | | 1 | 1 | 1 | +8 | 12 | 12 | | | | | | |
| -> 37 | INDEX RANGE SCAN (MIN/MAX) | PS_UPA_FIN_REG_TBL | 1 | 1 | 23 | +8 | 12 | 12 | | | | | | |
| -> 38 | BUFFER SORT | | 14 | 36 | 23 | +8 | 70 | 1870 | | | | | | |
| 39 | INDEX RANGE SCAN | PSAPWC_SUBIND_TBL | 14 | 1 | 1 | +8 | 1 | 27 | | | | | | |
| 40 | SORT AGGREGATE | | 1 | | 1 | +8 | 184 | 184 | | | | | | |
| 41 | FIRST ROW | | 1 | 2 | 1 | +8 | 184 | 184 | | | | | | |
| -> 42 | INDEX RANGE SCAN (MIN/MAX) | PS_PWC_SUBIND_TBL | 1 | 2 | 23 | +8 | 184 | 184 | | | | | | |
| 43 | BUFFER SORT | | 794 | 60 | 29 | +2 | 1870 | 13M | | | 306K | | 19.35 | Cpu (6) |
| 44 | TABLE ACCESS FULL | PS_UPA_CM_ADMIN_WL | 794 | 23 | 1 | +8 | 1 | 7052 | | | | | | |
| 45 | TABLE ACCESS FULL | PS_UPA_CM_PRE_ASGN | 3536 | 69 | | | | | | | | | | |
| 46 | INDEX RANGE SCAN | PSDUPA_CLIENT_TBL | 1 | 2 | | | | | | | | | | |
| 47 | SORT AGGREGATE | | 1 | | | | | | | | | | | |
| 48 | FIRST ROW | | 1 | 3 | | | | | | | | | | |
| 49 | INDEX RANGE SCAN (MIN/MAX) | PS_UPA_CLIENT_TBL | 1 | 3 | | | | | | | | | | |
| 50 | TABLE ACCESS BY INDEX ROWID | PS_UPA_CLIENT_TBL | 1 | 3 | | | | | | | | | | |
========================================================================================================================================================================================================
SQL>
spool offSQL> -
A lot of messages "direct path write temp" and "direct path read temp"
Hello, all
Please, understand me, what is going on in my system (DB: Oracle database 11.2.0.3, OS: Windows 2008 R2).
In AWR report (1 hour) I see next:
Foreground Wait Events
Avg
%Time Total Wait wait Waits % DB
Event Waits -outs Time (s) (ms) /txn time
direct path write temp 132,627 0 1,056 8 0.8 21.7
direct path read temp 308,969 0 565 2 2.0 11.6
log file sync 19,228 0 241 13 0.1 5.0
direct path write 17,698 0 135 8 0.1 2.8
db file sequential read 21,149 0 94 4 0.1 1.9
SQL*Net message from dblin 59 0 5 86 0.0 .1
Segments by Direct Physical Reads DB/Inst: SGRE/sgre Snaps: 1039-1040
-> Total Direct Physical Reads: 392,273
-> Captured Segments account for 94.7% of Total
Tablespace Subobject Obj. Direct
Owner Name Object Name Name Type Reads %Total
** MISSING TEMP ** TRANSIENT: 437734 MISSING ** UNDEF 38,290 9.76
DBSNMP TEMP MGMT_TEMPT_SQL TABLE 38,242 9.75
** MISSING TEMP ** TRANSIENT: 438784 MISSING ** UNDEF 37,790 9.63
** MISSING TEMP ** TRANSIENT: 437312 MISSING ** UNDEF 37,661 9.60
** MISSING TEMP ** TRANSIENT: 439257 MISSING ** UNDEF 37,477 9.55Some selects:
SELECT S.sid,
T.blocks * TBS.block_size / 1024 / 1024 mb_used, T.tablespace, T.SEGTYPE
FROM v$sort_usage T, v$session S, v$sqlarea Q, dba_tablespaces TBS
WHERE T.session_addr = S.saddr
AND T.sqladdr = Q.address (+)
AND T.tablespace = TBS.tablespace_name
AND S.sid = 732
ORDER BY S.username, S.sid;
SID MB_USED TABLESPACE SEGTYPE
732 2 TEMP LOB_DATA
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP INDEX
732 1 TEMP DATA
732 1 TEMP INDEX
732 1 TEMP LOB_INDEX
select st.sid, sn.name, st.VALUE
from V$statname sn, v$sesstat st
where st.STATISTIC# = sn.STATISTIC#
and (sn.name like 'sorts%')
and st.sid in (select sid from v$session_wait where event like '%direct path write temp%')
order by st.sid
SID NAME VALUE
732 sorts (memory) 591408
732 sorts (rows) 102126
732 sorts (disk) 0Why I do not see any disk sorts? If TEMP is used for no sort operations, then for which operations?
How I can see that? How can I decrease direct path write temp without tuning SQL?
Additional information:
PGA_AGGREGATE_TARGET is set to big value - 6GB (3GB enough due to advisory recommendation)
Please, help.
Regards, user12103911.user12103911 wrote:
SELECT optimal_count, round(optimal_count*100/total, 2) optimal_perc,
onepass_count, round(onepass_count*100/total, 2) onepass_perc,
multipass_count, round(multipass_count*100/total, 2) multipass_perc
FROM
(SELECT decode(sum(total_executions), 0, 1, sum(total_executions)) total,
sum(OPTIMAL_EXECUTIONS) optimal_count,
sum(ONEPASS_EXECUTIONS) onepass_count,
sum(MULTIPASSES_EXECUTIONS) multipass_count
FROM v$sql_workarea_histogram);
OPTIMAL_COUNT OPTIMAL_PERC ONEPASS_COUNT ONEPASS_PERC MULTIPASS_COUNT MULTIPASS_PERC
13150685 100 0 0 0 0No n-pass executions.That's a pretty convincing display - given that your AWR manages to NAME an object that is in the TEMP tablespace, an obvious point to follow up is global temporary tables. If you have any declared as "on commit preserve" (duration = 'SYS$SESSION') then you could have code which does "insert /*+ append */ into gtt", and if you then query this in parallel (or - since you're on 11.2.0.3 - the data volume is large enough) Oracle could choose to do direct path writes to load the GTT and direct path reads to read it back.
Regards
Jonathan Lewis -
What is p1 for direct path read temp wait event in 11gr1
hi friends,
When i run this query in my database(11gr1) i get this
SELECT P1,P1TEXT FROM V$ACTIVE_SESSION_HISTORY WHERE event='direct path write temp' and sql_id='2sd3hryy2baav';
P1 P1TEXT
1260 file number
As per the documentation given on the link
http://docs.oracle.com/cd/B28359_01/server.111/b28320/waitevents002.htm#
when i run the query for file#
select *
from v$datafile
where file# = file#;
i get no rows returned.
Can someone please tell me what is this value 1266??Hemant K Chitale wrote:
P1 as FILE_ID is actually the value of DB_FILES (an instance parameter) + the temp file id. Check if DB_FILES is set to 1250. In that case P1 of 1260 would mean the 10th TEMPFILE.
How did you came to know that P1.V$ACTIVE_SESSION_HISTORY = DB_FILES + the temp file id ?
Because when I checked in the docs it is saying :
P1 NUMBER First additional parameter
http://docs.oracle.com/cd/E11882_01/server.112/e25513/dynviews_1007.htm#REFRN30299
Kindly share with us the link, is possible please.
Regards
Girish Sharma -
WAIT = 'direct path read temp' in session
Hi;
select * from v$version
Oracle Database 11g Release 11.2.0.1.0 - 64bit Production
In our development system, a query "insert into X" using a couple of session global temporary tables, was running under 5 minuts, is now taking 40 minuts!
Sql Developer Sessions shows a wait: "direct path read temp"
Any hints on that might cause this, and possible solutions?
Trace file of the session looks like this:
*** 2013-03-18 15:56:22.871
WAIT #20: nam='direct path read temp' ela= 106 file number=201 first dba=46685 block cnt=31 obj#=61321 tim=1363614982871399
*** 2013-03-18 15:56:25.354
WAIT #20: nam='direct path read temp' ela= 90 file number=201 first dba=46336 block cnt=31 obj#=61321 tim=1363614985354148
*** 2013-03-18 15:56:28.098
WAIT #20: nam='direct path read temp' ela= 86 file number=201 first dba=46367 block cnt=31 obj#=61321 tim=1363614988098575
*** 2013-03-18 15:56:32.302
WAIT #20: nam='direct path read temp' ela= 112 file number=201 first dba=69438 block cnt=31 obj#=61321 tim=1363614992302296
WAIT #20: nam='direct path read temp' ela= 93 file number=201 first dba=69469 block cnt=31 obj#=61321 tim=1363614992302484
WAIT #20: nam='direct path read temp' ela= 95 file number=201 first dba=68030 block cnt=31 obj#=61321 tim=1363614992302888
WAIT #20: nam='direct path read temp' ela= 93 file number=201 first dba=66719 block cnt=31 obj#=61321 tim=1363614992303265
WAIT #20: nam='direct path read temp' ela= 107 file number=201 first dba=65726 block cnt=31 obj#=61321 tim=1363614992303657
WAIT #20: nam='direct path read temp' ela= 94 file number=201 first dba=64702 block cnt=31 obj#=61321 tim=1363614992304037
WAIT #20: nam='direct path read temp' ela= 97 file number=201 first dba=63709 block cnt=31 obj#=61321 tim=1363614992304421
WAIT #20: nam='direct path read temp' ela= 94 file number=201 first dba=62623 block cnt=31 obj#=61321 tim=1363614992304820
WAIT #20: nam='direct path read temp' ela= 111 file number=201 first dba=61471 block cnt=31 obj#=61321 tim=1363614992305227
WAIT #20: nam='direct path read temp' ela= 121 file number=201 first dba=60606 block cnt=31 obj#=61321 tim=1363614992305764
WAIT #20: nam='direct path read temp' ela= 100 file number=201 first dba=59392 block cnt=31 obj#=61321 tim=1363614992306175
WAIT #20: nam='direct path read temp' ela= 101 file number=201 first dba=58589 block cnt=31 obj#=61321 tim=1363614992306579
WAIT #20: nam='direct path read temp' ela= 98 file number=201 first dba=57503 block cnt=31 obj#=61321 tim=1363614992306965
WAIT #20: nam='direct path read temp' ela= 93 file number=201 first dba=56510 block cnt=31 obj#=61321 tim=1363614992307342
WAIT #20: nam='direct path read temp' ela= 94 file number=201 first dba=55296 block cnt=31 obj#=61321 tim=1363614992307742
WAIT #20: nam='direct path read temp' ela= 96 file number=201 first dba=54272 block cnt=31 obj#=61321 tim=1363614992308149
WAIT #20: nam='direct path read temp' ela= 131 file number=201 first dba=53407 block cnt=31 obj#=61321 tim=1363614992308651
WAIT #20: nam='direct path read temp' ela= 108 file number=201 first dba=52480 block cnt=31 obj#=61321 tim=1363614992309129
WAIT #20: nam='direct path read temp' ela= 99 file number=201 first dba=52511 block cnt=31 obj#=61321 tim=1363614992309273Tkprof output... notice the big values for direct path write temp and direct path read temp values!
OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
callcount cpu elapsed disk query current rows
Parse 2 0.17 0.18 0 0 0 0
Execute 2 0.00 0.00 0 0 0 0
Fetch 4 206.24 207.66 18960 755 21 8
total 8 206.42 207.84 18960 755 21 8
Misses in library cache during parse: 2
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
SQL*Net message to client 5 0.00 0.00
SQL*Net message from client 5 11.01 19.27
db file sequential read 6 0.00 0.00
Disk file operations I/O 15 0.00 0.00
asynch descriptor resize 84 0.00 0.00
direct path write temp 1264 0.19 1.25
direct path read temp 1264 0.00 0.04
control file sequential read 42 0.00 0.00
db file single write 3 0.00 0.00
control file parallel write 9 0.00 0.00
rdbms ipc reply 2 0.00 0.00
local write wait 12 0.00 0.00
log file sync 2 0.00 0.00
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 85 0.04 0.04 0 0 0 0
Execute 899 0.18 0.24 22 47 7 4
Fetch 1393 0.04 0.69 204 3200 0 7002
total 2377 0.28 0.98 226 3247 7 7006
Misses in library cache during parse: 55
Misses in library cache during execute: 51
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
db file sequential read 206 0.03 0.65
latch: shared pool 4 0.00 0.00
Disk file operations I/O 2 0.00 0.00
db file scattered read 3 0.03 0.04
5 user SQL statements in session.
896 internal SQL statements in session.
901 SQL statements in session.
Trace file: SXDB_ora_25080.trc
Trace file compatibility: 11.1.0.7
Sort options: default
1 session in tracefile.
5 user SQL statements in trace file.
896 internal SQL statements in trace file.
901 SQL statements in trace file.
41 unique SQL statements in trace file.
21517 lines in trace file.
217 elapsed seconds in trace file.
Edited by: PauloSMO on 19/Mar/2013 11:36 -
Oracle 10g direct path write too slow
Hi All,
We have Oracle 10g on a Solaris virtual server, VMWare ESXi being the host. Data files are on RAID1, internal storage on a HP DL585 with VMFS partition at ESXi level. Problem is that DB writes for a CREATE TABLE as SELECT... statement is way too slow. To create a table which is 0.5 GB, DB takes 9 minutes which amounts to 1 MB/s. When we check for FTP or file copy at Solaris level with same size file (0.5 GB), it flies through in less than a minute. This is Oracle 10.2.0.4, 8K data block, 2 vCPU assigned to the Solaris VM. Have checked with VMWare support for any known issues and also have SR open with Oracle for any param changes that can help speed up things. Any clues or pointers from you all will be of great help.
Thanks,
NikhilHere's the output from tkprof for waits
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
single-task message 1 0.17 0.17
SQL*Net message to dblink 150 0.00 0.00
SQL*Net message from dblink 150 0.04 0.32
SQL*Net message to client 1 0.00 0.00
direct path write temp 4003 1.16 804.93
direct path read temp 2563 0.14 35.86
SQL*Net more data from dblink 126967 0.17 11.81
SQL*Net message from client 1 17.73 17.73
Direct Path write temp has total waits of 804.93. Also, I am NOT looking to tune a particular SQL. Database is overall slow on VMware and I am looking for any gotchas for running Oracle 10g within a Solaris VM.
Thanks,
Nikhil -
Huge long time direct path read temp, but pga size is enough, one block p3
Hi Gurus,
Can you please kindly provide some points on my below questions. thanks
my env
select * from v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE 11.2.0.1.0 Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
OS: Linux 4 2.6.39-100.5.1.el5uek
session operation: update a partition which have 4 partitions and total 16G
session trace info:
the session keep at active status and waiting for below wait event for more than 70 hours, and os iostats and cpu are almost idle on most time.
WAIT #8: nam='direct path read temp' ela= 7615 file number=202 first dba=105072 block cnt=1 obj#=104719 tim=1344850223569499
WAIT #8: nam='direct path read temp' ela= 5989 file number=202 first dba=85264 block cnt=1 obj#=104719 tim=1344850392833257
WAIT #8: nam='direct path read temp' ela= 319 file number=202 first dba=85248 block cnt=1 obj#=104719 tim=1344850399563184
WAIT #8: nam='direct path read temp' ela= 358 file number=202 first dba=85232 block cnt=1 obj#=104719 tim=1344850406016899
WAIT #8: nam='direct path read temp' ela= 349 file number=202 first dba=85216 block cnt=1 obj#=104719 tim=1344850413023792
WAIT #8: nam='direct path read temp' ela= 7975 file number=202 first dba=85200 block cnt=1 obj#=104719 tim=1344850419495645
WAIT #8: nam='direct path read temp' ela= 331 file number=202 first dba=85184 block cnt=1 obj#=104719 tim=1344850426233450
WAIT #8: nam='direct path read temp' ela= 2641 file number=202 first dba=82880 block cnt=1 obj#=104719 tim=1344850432699800
pgastat:
NAME VALUE/1024/1024 UNIT
aggregate PGA target parameter 18432 bytes
aggregate PGA auto target 16523.1475 bytes
global memory bound 1024 bytes
total PGA inuse 75.7246094 bytes
total PGA allocated 162.411133 bytes
maximum PGA allocated 514.130859 bytes
total freeable PGA memory 64.625 bytes
PGA memory freed back to OS 40425.1875 bytes
total PGA used for auto workareas 2.75195313 bytes
maximum PGA used for auto workareas 270.407227 bytes
total PGA used for manual workareas 0 bytes
NAME VALUE/1024/1024 UNIT
maximum PGA used for manual workareas 24.5429688 bytes
bytes processed 110558.951 bytes
extra bytes read/written 15021.2559 bytes
Most operation in PGA via query on V$SQL_WORKAREA_ACTIVE
IDX maintainenance (sort)
My questions:
1. why 'direct path read temp' just read one block every time, my understanding is this event can read one block and multiple blocks at one read call, why it keep read one block in my session?
2. my pga size is big enough, why this operation can not be treated with in PGA memory, instead of read block from disk into temp tablespace?
Thanks for you inputs.
Roy951241 wrote:
since the session(which was from hard code application) is completed.First of all, you showed wait events from sql trace in the first post. Is the tracing was disabled in the latest execution?
>
I just generated the AWR for that period, as get long elapsed time SQL as following
Elapsed Time (s) Executions Elapsed Time per Exec (s) %Total %CPU %IO SQL Id
3,075.35 0 85.10 91.03 8.68 duhz2wtduz709
524.11 1 524.11 14.50 99.29 0.30 3cpa9fxny9j35
so I get execution plan as below for these two SQL,
select * from table(dbms_xplan.display_awr('&v_sql_id')); duhz2wtduz709
PLAN_TABLE_OUTPUT
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | UPDATE STATEMENT | | | | 4 (100)| |
| 1 | UPDATE | WORK_PAY_LINE | | | | |
| 2 | INDEX RANGE SCAN| WORK_PAY_LINE | 1 | 37 | 3 (0)| 00:00:01 |
Note
- automatic DOP: Computed Degree of Parallelism is 1 because of parallel thresholdI am not sure the why elapsed time in AWR is different with time in execution plan. Column "Time" in an execution plan is estimated time. In this execution plan Oracle expects to get 1 row, estimated time is 1 sec.
So, you need to check why estimated cardinality is such low, check statistics on the table WORK_PAY_LINE.
You update 10Gb from 16Gb table via Index Range Scan, it looks inefficient here by two reasons:
1. when a table updated via Index Range Scan optimized index maintenance is used. As a result some amount (significant in your case) of workareas is required. Required size depends on size and number of updated indexes and "global memory bound", 1Gb in your case.
2. if required table buffers will not be found in the cache it will be read from disk by single block reads. If you would use Full Table Scan then buffers for update most likely will be found in the cache because before it read by multiblock reads during Full Table Scan.
Figures from your AWR indicate, that only ~ 9% the session waited for I/O and 91% it worked and used CPU
Elapsed Time (s) Executions Elapsed Time per Exec (s) %Total %CPU %IO SQL Id
3,075.35 0 85.10 91.03 8.68 duhz2wtduz709 This amount of CPU time partially required for UPDATE 10Gb of data, partially for sorting during optimized index maintenance.
I would propose to use Table Full Scan here.
Also you can play around and create fake trigger on update, it will make impossible to use optimized index maintenance, usual index maintenance will be used. As a result you can check the same update with the same execution plan (with Index Range Scan) but without optimized index maintenance and "direct path .. temp" wait events.
Alexander Anokhin
http://alexanderanokhin.wordpress.com/ -
Wait events 'direct path write' and 'direct path read'
Hi,
We have a query which is taking more that 2 min. It's a 9.2.0.7 database. We took the trace/tkprof of the query,and identified that there are so manay 'direct path write' and 'direct path read' wait events in the trace file.
WAIT #3: nam='direct path write' ela= 5 p1=201 p2=70710 p3=15
WAIT #3: nam='direct path read' ela= 170 p1=201 p2=71719 p3=15
In the above, "p1=201" is a file_id, but we could not find any data file, temp file, control file with that id# 201.
Can you please let us know what's "p1=201" here, how to identify the file which is causing the issue.
Thanks
SravanWhat does:
show parameter db_filesreturn? My guess, is that it returns 200.
The direct file read and direct file write events are reads and writes to TEMP tablespace. In those wait events, the file# is reported as db_files+temp file id. So, 201 means temp file #1.
Now, as to your actual performance problem.
Without seeing the SQL and the corresponding execution plan, it's impossible to be sure. However, the most common causes of temp writes are sort operations and group by operations.
If you decide to post your SQL and execution plan, please be sure to make it readable by formatting it. Information on how to do so can be found here.
Hope that helps,
-Mark
Edited by: mbobak on May 1, 2011 1:50 AM -
Hi All,
DB version is 10.2.0.4
An insert statement is running for almost 14 hours now. The wait event shows direct path read temp
SID EVENT WAIT_TIME SECONDS_IN_WAIT P1 P2
1264 direct path read temp -1 0 524 64626Read about this event, which says it might happen due to Parallel full table scan not using the index. But that is not happening here..
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | INSERT STATEMENT | | 1 | 512 | 941 (1)| 00:00:12 |
| 1 | COUNT | | | | | |
|* 2 | FILTER | | | | | |
| 3 | NESTED LOOPS | | 1 | 512 | 941 (1)| 00:00:12 |
| 4 | NESTED LOOPS | | 1 | 506 | 940 (1)| 00:00:12 |
| 5 | NESTED LOOPS | | 1 | 493 | 938 (1)| 00:00:12 |
| 6 | NESTED LOOPS | | 1 | 478 | 937 (1)| 00:00:12 |
| 7 | NESTED LOOPS | | 1 | 439 | 936 (1)| 00:00:12 |
| 8 | NESTED LOOPS | | 1 | 420 | 934 (1)| 00:00:12 |
| 9 | NESTED LOOPS | | 1 | 382 | 932 (1)| 00:00:12 |
| 10 | NESTED LOOPS | | 1 | 377 | 931 (1)| 00:00:12 |
| 11 | NESTED LOOPS | | 1 | 295 | 929 (1)| 00:00:12 |
| 12 | NESTED LOOPS | | 1 | 280 | 927 (1)| 00:00:12 |
| 13 | NESTED LOOPS | | 1 | 273 | 927 (1)| 00:00:12 |
| 14 | NESTED LOOPS | | 1 | 247 | 925 (1)| 00:00:12 |
| 15 | NESTED LOOPS | | 1 | 239 | 924 (1)| 00:00:12 |
| 16 | NESTED LOOPS | | 1 | 212 | 922 (1)| 00:00:12 |
| 17 | NESTED LOOPS | | 1 | 205 | 921 (1)| 00:00:12 |
| 18 | NESTED LOOPS | | 1 | 184 | 156 (1)| 00:00:02 |
| 19 | NESTED LOOPS | | 1 | 109 | 154 (1)| 00:00:02 |
| 20 | NESTED LOOPS | | 1 | 93 | 153 (1)| 00:00:02 |
|* 21 | HASH JOIN | | 4 | 284 | 145 (1)| 00:00:02 |
|* 22 | TABLE ACCESS BY INDEX ROWID | GL_JE_LINES | 65 | 2730 | 130 (0)| 00:00:02 |
| 23 | NESTED LOOPS | | 75 | 4500 | 140 (0)| 00:00:02 |
| 24 | MERGE JOIN CARTESIAN | | 1 | 18 | 10 (0)| 00:00:01 |
| 25 | TABLE ACCESS FULL | FND_PRODUCT_GROUPS | 1 | 2 | 2 (0)| 00:00:01 |
| 26 | BUFFER SORT | | 1 | 16 | 8 (0)| 00:00:01 |
|* 27 | TABLE ACCESS BY INDEX ROWID| GL_CODE_COMBINATIONS | 1 | 16 | 8 (0)| 00:00:01 |
|* 28 | INDEX RANGE SCAN | JSW_GL_CODE_COMB_SEG_IDX | 10 | | 2 (0)| 00:00:01 |
|* 29 | INDEX RANGE SCAN | GL_JE_LINES_N1 | 933 | | 6 (0)| 00:00:01 |
|* 30 | TABLE ACCESS FULL | GL_PERIODS | 5 | 55 | 4 (0)| 00:00:01 |
|* 31 | TABLE ACCESS BY INDEX ROWID | GL_JE_HEADERS | 1 | 22 | 2 (0)| 00:00:01 |
|* 32 | INDEX UNIQUE SCAN | GL_JE_HEADERS_U1 | 1 | | 1 (0)| 00:00:01 |
| 33 | TABLE ACCESS BY INDEX ROWID | GL_CODE_COMBINATIONS | 1 | 16 | 1 (0)| 00:00:01 |
|* 34 | INDEX UNIQUE SCAN | GL_CODE_COMBINATIONS_U1 | 1 | | 0 (0)| 00:00:01 |
|* 35 | TABLE ACCESS BY INDEX ROWID | GL_JE_BATCHES | 1 | 75 | 2 (0)| 00:00:01 |
|* 36 | INDEX UNIQUE SCAN | GL_JE_BATCHES_U1 | 1 | | 1 (0)| 00:00:01 |
|* 37 | TABLE ACCESS BY INDEX ROWID | MTL_TRANSACTION_ACCOUNTS | 1 | 21 | 765 (0)| 00:00:10 |
|* 38 | INDEX RANGE SCAN | MTL_TRANSACTION_ACCOUNTS_N3 | 4021 | | 28 (0)| 00:00:01 |
|* 39 | TABLE ACCESS BY INDEX ROWID | HR_ALL_ORGANIZATION_UNITS | 1 | 7 | 1 (0)| 00:00:01 |
|* 40 | INDEX UNIQUE SCAN | HR_ORGANIZATION_UNITS_PK | 1 | | 0 (0)| 00:00:01 |
|* 41 | TABLE ACCESS BY INDEX ROWID | HR_ORGANIZATION_INFORMATION | 1 | 27 | 2 (0)| 00:00:01 |
|* 42 | INDEX RANGE SCAN | HR_ORGANIZATION_INFORMATIO_FK2 | 1 | | 1 (0)| 00:00:01 |
| 43 | TABLE ACCESS BY INDEX ROWID | MTL_PARAMETERS | 1 | 8 | 1 (0)| 00:00:01 |
|* 44 | INDEX UNIQUE SCAN | MTL_PARAMETERS_U1 | 1 | | 0 (0)| 00:00:01 |
|* 45 | TABLE ACCESS BY INDEX ROWID | HR_ORGANIZATION_INFORMATION | 1 | 26 | 2 (0)| 00:00:01 |
|* 46 | INDEX RANGE SCAN | HR_ORGANIZATION_INFORMATIO_FK2 | 1 | | 1 (0)| 00:00:01 |
|* 47 | INDEX UNIQUE SCAN | HR_ALL_ORGANIZATION_UNTS_TL_PK | 1 | 7 | 0 (0)| 00:00:01 |
|* 48 | TABLE ACCESS BY INDEX ROWID | MTL_MATERIAL_TRANSACTIONS | 1 | 15 | 2 (0)| 00:00:01 |
|* 49 | INDEX UNIQUE SCAN | MTL_MATERIAL_TRANSACTIONS_U1 | 1 | | 1 (0)| 00:00:01 |
| 50 | TABLE ACCESS BY INDEX ROWID | MTL_SYSTEM_ITEMS_B | 1 | 82 | 2 (0)| 00:00:01 |
|* 51 | INDEX UNIQUE SCAN | MTL_SYSTEM_ITEMS_B_U1 | 1 | | 1 (0)| 00:00:01 |
|* 52 | INDEX FULL SCAN | GL_SETS_OF_BOOKS_U2 | 1 | 5 | 1 (0)| 00:00:01 |
|* 53 | TABLE ACCESS BY INDEX ROWID | RCV_TRANSACTIONS | 1 | 38 | 2 (0)| 00:00:01 |
|* 54 | INDEX UNIQUE SCAN | RCV_TRANSACTIONS_U1 | 1 | | 1 (0)| 00:00:01 |
|* 55 | TABLE ACCESS BY INDEX ROWID | PO_HEADERS_ALL | 1 | 19 | 2 (0)| 00:00:01 |
|* 56 | INDEX UNIQUE SCAN | PO_HEADERS_U1 | 1 | | 1 (0)| 00:00:01 |
| 57 | TABLE ACCESS BY INDEX ROWID | PO_VENDORS | 1 | 39 | 1 (0)| 00:00:01 |
|* 58 | INDEX UNIQUE SCAN | PO_VENDORS_U1 | 1 | | 0 (0)| 00:00:01 |
| 59 | TABLE ACCESS BY INDEX ROWID | PO_VENDOR_SITES_ALL | 1 | 15 | 1 (0)| 00:00:01 |
|* 60 | INDEX UNIQUE SCAN | PO_VENDOR_SITES_U1 | 1 | | 0 (0)| 00:00:01 |
| 61 | TABLE ACCESS BY INDEX ROWID | RCV_SHIPMENT_HEADERS | 1 | 13 | 2 (0)| 00:00:01 |
|* 62 | INDEX UNIQUE SCAN | RCV_SHIPMENT_HEADERS_U1 | 1 | | 1 (0)| 00:00:01 |
|* 63 | INDEX UNIQUE SCAN | RCV_SHIPMENT_LINES_U1 | 1 | 6 | 1 (0)| 00:00:01 |
---------------------------------------------------------------------------------------------------------------------------------------The PGA size is 5gb. What is the cause of this wait event?
baskar.lHi,
How do i resolve this..?
Read from the document Optimizer Selects the Merge Join Cartesian Despite the Hints (Doc ID 457058.1)
| 24 | MERGE JOIN CARTESIAN | | 1 | 18 | 10 (0)| 00:00:01 |
| 25 | TABLE ACCESS FULL | FND_PRODUCT_GROUPS | 1 | 2 | 2 (0)| 00:00:01 |
| 26 | BUFFER SORT | | 1 | 16 | 8 (0)| 00:00:01 |
|* 27 | TABLE ACCESS BY INDEX ROWID| GL_CODE_COMBINATIONS | 1 | 16 | 8 (0)| 00:00:01 |
|* 28 | INDEX RANGE SCAN | JSW_GL_CODE_COMB_SEG_IDX | 10 | | 2 (0)| 00:00:01 |Have set
SQL> alter session set "_optimizer_mjc_enabled"=false ;
|* 21 | HASH JOIN | | 4 | 284 | 139 (1)| 00:00:02 |
|* 22 | TABLE ACCESS BY INDEX ROWID | GL_JE_LINES | 65 | 2730 | 124 (0)| 00:00:02 |
| 23 | NESTED LOOPS | | 75 | 4500 | 134 (0)| 00:00:02 |
| 24 | NESTED LOOPS | | 1 | 18 | 10 (0)| 00:00:01 |
| 25 | TABLE ACCESS FULL | FND_PRODUCT_GROUPS | 1 | 2 | 2 (0)| 00:00:01 |
|* 26 | TABLE ACCESS BY INDEX ROWID| GL_CODE_COMBINATIONS | 1 | 16 | 8 (0)| 00:00:01 |
|* 27 | INDEX RANGE SCAN | JSW_GL_CODE_COMB_SEG_IDX | 10 | | 2 (0)| 00:00:01 |thanks,
baskar.l -
Query regarding direct path write
Hi All,
We have Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production running on Redhat 4.
We have performance issue with high disk utilization.
When seen statspack report, top event is always direct path write.
when checked about direct path write found that it is consequence of direct path inserts/high sort operations.
I checked v$sort_usage and identified query which is listed there most of time, but column segtype is HASH for that query.
So is there chance i can conclude that this is the query which is causing direct path writes as confusing thing is SEGTYPE is HASH.
Please let me know your comment about the same and also is there a way i can find sql statement which are writing to temp tablespace using direct path write.
Regards
Vinayv$sql_workarea_active gives information about the active work areas in the system. It shows the operation type, sid, memory usage and temp tablespace usage. You can check this to see what session is using the temporary tablespace for work areas.
-
Is there a way to get Toplink to use direct path write (use the 'append' hint)?
Thanks,
Mikep.s. we are using the BPEL database adapter...
-
Wait Event Direct path read TEMP
HI,
I have two sessions waiting on wait event "DIECT PATH READ TEMP" (both the sessions with same SQL).Those sessions are almost in hung state.If i run that query from any other session,even that gets hanged.I have generated 10046 trace for these and found that all of them are waiting for a index object in TEMP datafile.
Has anyone of you had the same issue.
Please explain me what kind of action i have taken.
I have verified the stats..they are all up to date.
Thanks,
Pramod GarreHi ,
It is IMPOSSIBLE for two SELECT statements to obstruct each other.-
Its not impossible my dear.Do you know something called "Hot Block".Dont you know that in that case select queries obstruct each other??Dont suggest if you dont know.
If you don't post meaningful information, you'll be left with your own mystery-
I agree i have to provide more information.
Thanks
Pramod -
Hi,
Oracle Version : 11.2.0.1(Standard Edition)
Operating System : RHEL-5
We are having one Procedure which is causing Direct Path Temp Write Even. How can we avoid that and it is taking lot of time for execution.
Please help me how solve my problem.
Thanks & Regards,
Poorna Prasad.SSIDDABATHUNI wrote:
Hi,
Oracle Version : 11.2.0.1(Standard Edition)
Operating System : RHEL-5
We are having one Procedure which is causing Direct Path Temp Write Even. How can we avoid that and it is taking lot of time for execution.
Please help me how solve my problem.
Thanks & Regards,
Poorna Prasad.SRead Charles Hooper comments on this event from this post direct path write temp wait event on temp lob -
Query Tuning (sequential read + direct path read/write temp)
Following query takes nearly 10 minutes under 10.2.0.2 on WIN2K3 to execute but I am sure there would be an alternate to tune it further.
Major waits are 'db file sequential read' and 'direct path read temp' in addition to 'direct path write temp'
Increasing/tuning the work_area_policy/sort_area_size would help? moving the tables to faster disk would reduce PIO causing sequential read, query re-writing would prove to be helpful?.
Below is the tkprof:
SELECT
P.PER_ID
, CL.DESCR
, P.ENG_NAME
, P.ARA_NAME
, P.NATION
, P.ADDR
, ('Mob:' || NVL(P.MOB, '') || ', Home:' || NVL(P.HOME, '') || ', Bus.:' || NVL(P.BUS, '') || ', Fax:' || NVL(P.FAX, '')) PHONE
, SUM(CASE
WHEN FT.FT_TYPE_FLG IN ('BS','BX','AD','AX') THEN FT.CUR_AMT
ELSE 0
END) BILL
, SUM(CASE
WHEN FT.FT_TYPE_FLG IN ('PS','PX') THEN FT.CUR_AMT * -1
ELSE 0
END) PAY
, SUM(FT.CUR_AMT) DUE
, SUM(CASE
WHEN FT.FREEZE_DTTM > '03-JUN-08' THEN
CASE WHEN FT.FT_TYPE_FLG IN ('PS','PX') THEN FT.CUR_AMT * -1
ELSE 0
END
ELSE 0
END) PAY_02JUN
FROM
CI_FT FT
, CI_SA SA
, CI_ACCT_CHAR AC
, CI_CUST_CL_L CL
, CI_ACCT A
, CI_ACCT_PER AP
SELECT
P.PER_ID
, (P.CITY || ', ' || P.STATE || ',' || P.COUNTRY) ADDR
, MAX(DECODE(PP.PHONE_TYPE_CD, 'MOB ', PP.PHONE)) MOB
, MAX(DECODE(PP.PHONE_TYPE_CD, 'BUSN ', PP.PHONE)) BUS
, MAX(DECODE(PP.PHONE_TYPE_CD, 'HOME ', PP.PHONE)) HOME
, MAX(DECODE(PP.PHONE_TYPE_CD, 'FAX ', PP.PHONE)) FAX
, MAX(DECODE(PN.NAME_TYPE_FLG, 'PRIM', PN.ENTITY_NAME)) ENG_NAME
, MAX(DECODE(PN.NAME_TYPE_FLG, 'ALT ', PN.ENTITY_NAME)) ARA_NAME
, MAX(DECODE(PC.CHAR_TYPE_CD, 'NATION ', PC.CHAR_VAL)) NATION
FROM
CI_PER P
, CI_PER_PHONE PP
, CI_PER_NAME PN
, CI_PER_CHAR PC
WHERE
P.PER_ID = PP.PER_ID (+)
AND P.PER_ID = PN.PER_ID (+)
AND P.PER_ID = PC.PER_ID (+)
GROUP BY
P.PER_ID
, (P.CITY || ', ' || P.STATE || ',' || P.COUNTRY)
) P
WHERE
P.PER_ID = AP.PER_ID
AND AP.ACCT_ID = AC.ACCT_ID
AND AP.ACCT_ID = SA.ACCT_ID
AND AP.MAIN_CUST_SW = 'Y'
AND A.ACCT_ID = SA.ACCT_ID
AND A.ACCT_ID = AP.ACCT_ID
AND AC.CHAR_TYPE_CD = 'ACCTYPE'
AND AC.CHAR_VAL IN ('UOS', 'DEFAULT')
AND AC.ACCT_ID = SA.ACCT_ID
AND CL.LANGUAGE_CD = 'ENG'
AND A.ACCT_ID = AC.ACCT_ID
AND A.CUST_CL_CD = CL.CUST_CL_CD
AND SA.SA_ID = FT.SA_ID
AND FT.FREEZE_DTTM IS NOT NULL
GROUP BY
P.PER_ID
, CL.DESCR
, P.ENG_NAME
, P.ARA_NAME
, P.NATION
, P.ADDR
, ('Mob:' || NVL(P.MOB, '') || ', Home:' || NVL(P.HOME, '') || ', Bus.:' || NVL(P.BUS, '') || ', Fax:' || NVL(P.FAX, ''))
HAVING
SUM(FT.CUR_AMT) > 0
call count cpu elapsed disk query current rows
Parse 1 0.64 0.64 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 304 353.09 430.04 21720 52997832 0 4543
total 306 353.73 430.69 21720 52997832 0 4543
Misses in library cache during parse: 1
Optimizer mode: CHOOSE
Parsing user id: 79 (CISADM)
Rows Row Source Operation
4543 FILTER (cr=52997832 pr=21720 pw=10311 time=430019418 us)
5412 HASH GROUP BY (cr=52997832 pr=21720 pw=10311 time=430015729 us)
199471 VIEW (cr=52997832 pr=21720 pw=10311 time=423392346 us)
199471 HASH GROUP BY (cr=52997832 pr=21720 pw=10311 time=423192867 us)
4013304 TABLE ACCESS BY INDEX ROWID CI_FT (cr=52997832 pr=11409 pw=0 time=140469508 us)
17717785 NESTED LOOPS (cr=49295470 pr=8987 pw=0 time=407554071 us)
13704480 NESTED LOOPS (cr=21818135 pr=7655 pw=0 time=287797921 us)
2782119 NESTED LOOPS OUTER (cr=3915432 pr=2950 pw=0 time=38953485 us)
571492 NESTED LOOPS OUTER (cr=2545763 pr=2711 pw=0 time=7433194 us)
286061 NESTED LOOPS OUTER (cr=2253263 pr=2671 pw=0 time=26607373 us)
123411 NESTED LOOPS (cr=1989056 pr=2642 pw=0 time=22711194 us)
123411 NESTED LOOPS (cr=1864959 pr=2642 pw=0 time=20860026 us)
123411 NESTED LOOPS (cr=1494040 pr=1754 pw=0 time=15553373 us)
243088 NESTED LOOPS (cr=29540 pr=1754 pw=0 time=10213331 us)
13227 TABLE ACCESS FULL CI_PER (cr=251 pr=49 pw=0 time=43331 us)
243088 INDEX RANGE SCAN XM150S1 (cr=29289 pr=1705 pw=0 time=6178159 us)(object id 97173)
123411 INLIST ITERATOR (cr=1464500 pr=0 pw=0 time=7220251 us)
123411 INDEX RANGE SCAN CM064S0 (cr=1464500 pr=0 pw=0 time=5631936 us)(object id 108631)
123411 TABLE ACCESS BY INDEX ROWID CI_ACCT (cr=370919 pr=888 pw=0 time=7241286 us)
123411 INDEX UNIQUE SCAN XM148P0 (cr=247508 pr=0 pw=0 time=1198649 us)(object id 97147)
123411 TABLE ACCESS BY INDEX ROWID CI_CUST_CL_L (cr=124097 pr=0 pw=0 time=1391837 us)
123411 INDEX UNIQUE SCAN XC523P0 (cr=686 pr=0 pw=0 time=595005 us)(object id 97745)
283749 TABLE ACCESS BY INDEX ROWID CI_PER_PHONE (cr=264207 pr=29 pw=0 time=3549713 us)
283749 INDEX RANGE SCAN XM172P0 (cr=125886 pr=4 pw=0 time=1307395 us)(object id 98733)
571492 INDEX RANGE SCAN XM171S2 (cr=292500 pr=40 pw=0 time=2976807 us)(object id 98728)
2777066 TABLE ACCESS BY INDEX ROWID CI_PER_CHAR (cr=1369669 pr=239 pw=0 time=23084761 us)
2777066 INDEX RANGE SCAN XM168P0 (cr=596156 pr=53 pw=0 time=7394319 us)(object id 98719)
13704480 TABLE ACCESS BY INDEX ROWID CI_SA (cr=17902703 pr=4705 pw=0 time=163320548 us)
13704480 INDEX RANGE SCAN XM199S1 (cr=5688247 pr=104 pw=0 time=51063061 us)(object id 98973)
4013304 INDEX RANGE SCAN CM112S1 (cr=27477335 pr=1332 pw=0 time=124063022 us)(object id 116797)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 304 0.00 0.00
db file sequential read 11366 0.34 65.63
direct path write temp 1473 0.06 2.91
latch: cache buffers chains 17 0.00 0.00
db file scattered read 7 0.01 0.03
read by other session 2 0.00 0.00
direct path read temp 1473 0.03 6.85
SQL*Net message from client 304 0.02 2.74
SQL*Net more data to client 292 0.00 0.00
********************************************************************************Luckys
I've just realised that I mis-read part of your plan:
199471 HASH GROUP BY (cr=52997832 pr=21720 pw=10311 time=423192867 us)
4013304 TABLE ACCESS BY INDEX ROWID CI_FT (cr=52997832 pr=11409 pw=0 time=140469508 us)
17717785 NESTED LOOPS (cr=49295470 pr=8987 pw=0 time=407554071 us)The time component for a line is the time it supplies, plus the sum of the time from its direct descendents.
In this case I looked at the HASH GROUP BY and TABLE ACCESS and got a difference of about 283 seconds. In fact I should have taken more notice of the other lines in the plan - comparing the HASH GROUP BY with the NESTED LOOP for a difference of about 16 seconds and assuming that the time in the TABLE ACCESS line was not to be trusted. (See http://jonathanlewis.wordpress.com/2007/04/26/heisenberg/ for a couple of comments on the timing issue).
So the grouping is responsible for relatively little of the excess time - most of the time goes into the nested loop.
I shall be using the Hints as advised, when we say we
have to "rewrite the query"
given the current context excluding the HINTS, what
exactly should I be
considering in terms of query rewrite, what
additional intelligence I can add to the
query in question so that CBO produces a different
plan.
The main consideration is what the query is supposed to report. Compare this with the way the optimizer is running the query and see if it makes sense.
When are talking about high intermediate rows
processing are we referring to this
section of the plan?;
4013304 TABLE ACCESS BY INDEX ROWID CI_FT
(cr=52997832 pr=11409 pw=0 time=140469508 us)
17717785 NESTED LOOPS (cr=49295470 pr=8987
pw=0 time=407554071 us)
13704480 NESTED LOOPS (cr=21818135 pr=7655
pw=0 time=287797921 us)
2782119 NESTED LOOPS OUTER (cr=3915432
pr=2950 pw=0 time=38953485 us)
2777066 TABLE ACCESS BY INDEX ROWID
CI_PER_CHAR (cr=1369669 pr=239 pw=0 time=23084761
us)
2777066 INDEX RANGE SCAN XM168P0 (cr=596156
pr=53 pw=0 time=7394319 us)(object id 98719)
13704480 TABLE ACCESS BY INDEX ROWID CI_SA
(cr=17902703 pr=4705 pw=0 time=163320548 us)
13704480 INDEX RANGE SCAN XM199S1
(cr=5688247 pr=104 pw=0 time=51063061 us)(object id
98973)
4013304 INDEX RANGE SCAN CM112S1 (cr=27477335
pr=1332 pw=0 time=124063022 us)(object id 116797)
Correct - one of the nested loops returns 2.78M rows - but as you run the next join you end up collecting 13.7M entires from the next index and table. That step is responsible for quite a lot of your work and time (as is the following step where you USE the 13.7M rows to probe the next index/table combination). If the optimizer had not grown the data set by merging the P view earlier on, the data sizes would be significantly smaller at that point.
Your inline view looks as if it is trying to turn rows into columns (the max(decode()) trick) - which is why I think it might be a good idea to stop Oracle from merging the view. So, as I suggested, look at the query withouth that bit of complexity and work out a sensible way to walk through the tables - bearing in mind the statistics below and the available indexes, and the amount of data your predicates identify at each stage.
Moreover tables have been analyzed:
CI_ACCT 243068
CI_ACCT_CHAR 222320
CI_ACCT_PER 242971
CI_FT 794510
CI_PER 13227
CI_PER_CHAR 42555
CI_PER_PHONE 18488
CI_SA 1082301
Parameters:
optimizer_features_enable string 10.2.0.2
optimizer_index_caching integer 100
optimizer_index_cost_adj integer 1
Unless you've been given strict instructions by a 3rd-part supplier, those settings for the optimizer_index_caching and optimizer_index_cost_adj are particularly bad - especially in 10g. With those settings, the optimizer is quite likely to choose stupid plans with excessive use of indexes - and pick the wrong index while doing it.
It's not appropriate to fiddle with system parameters to address one query - but at some stage you need to rethink your entire set of parameter settings to do things the 10g way. See this note from the Optimizer Group: http://www.oracle.com/technology/products/bi/db/10g/pdf/twp_bidw_optimizer_10gr2_0208.pdf
Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
http://www.jlcomp.demon.co.uk
"The greatest enemy of knowledge is not ignorance,
it is the illusion of knowledge." Stephen Hawking.
Maybe you are looking for
-
Performance issue in DB need help with analysing this ADDM report
Hi, My environment: Os: RHEL5U3 / 11.1.0.7 64 bit / R12.1.1 64 bit Issue: Few days are am facing serious of performance problem in our Production instance. Normally the issue will occur 5 to 10 minutes occasionally per day. At the time of issue we no
-
Dear BI Experts, We have data loaded in FIAR & FIAP DSO and Cube from 2001 to Sep-2010(Full load) Now the time to populate delta for both the cubes. When onwards delta is required?One of my user saying only Sep-2010 period is open and all other perio
-
Iphoto freezes when I open iPhoto preferences
Everytime I open iPhoto and then go to preferences, I get the rainbow wheel and the whole program freezes. I end up having to force quit. I don't know how to get around this as I've rebooted my iMac numerous times and it makes no difference. Am I doo
-
Mass upload of documents over FlexUI
Hi, is it possible to implement a mass upload of files to the portal km over the FlexUI? Best regards, Thomas Kuri
-
On Time Delivey and reason coding for late
Were on ECC 5.0 and looking at trying to link "reasons" for late delivery to the SAP shipment. Has anyone done this or have any suggestions on ways to configure list of "reasons" and how to link them to the shipment number? In 3.1i we had a way to