Sequential reads vs Direct reads
Hello gurus,
Could you please let me know what are the main difference between direct reads and sequential reads in terms of performance?
Thanks and best regards,
Mainly, Direct Read refers to accesses in which a maximum of one line is returned by the database, otherwise Sequential Read refers to all other read database accesses, in which there may be more than one line returned.
In case of Sequential Read, when you perform a trace on these queries you will see that index is used in most cases. However Direct Read have better performance than Sequential.
Similar Messages
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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. -
Direct Path Reads instead of Sequential Reads for index range scan
Database is 11.2. I have two development schemas, with the same table loaded in each schema - a 5 million row table. The execution path for the sql statement is the same against both tables; it's doing an index range scan.
But it would appear Oracle performs a direct path read against one schema, and performs sequential reads against the other schema. I don't understand why I'm seeing different behavior when the execution plan is the same. Any ideas? These are two different schemas in the same database.There is not enough information.So you even these tables located same database and you gathered statistics it is not mean both run time wait event statistics must be same.Really they are different tables.If both query use INDEX RANGE SCAN the it is not mean these plans are same.What about table and their index statistics? are they same? for example num_row or num_blocks of both tables are same? also about indexes.In additionally if you want to get exact reason you can enable sql trace(using dbms_monitor or setting sql_trace parameter to true according session) and need analyze result trace file using tkprof utility.In additionally in 11g here when query execution time oracle automatically choose direct read path(serial) based on size of tables and size of buffer cache(also here is available some hidden parameter to controlling this behavior).
-
Sequential read vs direct read master data in Query
Hey all,
I use class cl_rsr_request to get data from a query in ABAP.
When I look at SM50 when executing my code, I see the following
Report action table
"CL_RSDM_READ_MASTER_DATA======CP" "Sequential read" "/BIC/SZINSTALL"
Why is this a sequential read?
I would expect a direct read, sequential read are much slower ....
Other tables have a direct read, example /BIC/PZADDR_NUM.
P-tables are masterdata tables and S-tables are SID tables, is this correct?
StevenHi,
a sequential read may be necessary due to wrong or not exisitng indexes on the SID table. In RSRV you can check your characteristic or in SE11 goto indexes. There you can see which indexes are active and generated. DOes ZINSTALL have attributes and you may want to read not all fo ZINSTALL but only where certain attributes are filled. For this you may need a special index.
You rifht P table are master data tables with all attributes of your characterisitc, S-tables are the sid tabels.
Regards,
Juergen -
Update Statement Simply hanged but doing db file sequential read
Hi,
Last night we had issue with one of the prod server where we updating one of table which contains large number records in millions.Same identical machine completed in1 hour and other box never completed but doing db file sequential read but in the long ops the last statement it was done 20:16 after that nothing is happening but i ran few trace on that user.
/u01/app/oracle/admin/SURV2/udump/surv2_ora_10048.trc
Oracle Database 10g Release 10.2.0.4.0 - Production
ORACLE_HOME = /u01/app/oracle/product/10.2.0/db
System name: SunOS
Node name: prdfa001
Release: 5.10
Version: Generic_139556-08
Machine: i86pc
Instance name: SURV2
Redo thread mounted by this instance: 1
Oracle process number: 18
Unix process pid: 10048, image: oracle@prdfa001
*** 2010-09-09 23:37:07.484
*** ACTION NAME:() 2010-09-09 23:37:07.473
*** MODULE NAME:(SQL*Plus) 2010-09-09 23:37:07.473
*** SERVICE NAME:(SURV2) 2010-09-09 23:37:07.473
*** SESSION ID:(289.54) 2010-09-09 23:37:07.473
Received ORADEBUG command 'unlimit' from process Unix process pid: 3983, image:
*** 2010-09-09 23:37:20.315
Received ORADEBUG command 'event 10046 trace name context forever, level 12' from process Unix process pid: 3983, image:
WAIT #7: nam='db file sequential read' ela= 11160 file#=13 block#=2252349 blocks=1 obj#=166421 tim=12499462835161
WAIT #7: nam='db file sequential read' ela= 2857 file#=13 block#=2249751 blocks=1 obj#=166421 tim=12499462838137
WAIT #7: nam='db file sequential read' ela= 3810 file#=13 block#=2251361 blocks=1 obj#=166421 tim=12499462842048
WAIT #7: nam='db file sequential read' ela= 4459 file#=13 block#=2247059 blocks=1 obj#=166421 tim=12499462846564
WAIT #7: nam='db file sequential read' ela= 2841 file#=13 block#=2247507 blocks=1 obj#=166421 tim=12499462849468
WAIT #7: nam='db file sequential read' ela= 427 file#=13 block#=2247568 blocks=1 obj#=166421 tim=12499462850032
WAIT #7: nam='db file sequential read' ela= 1187 file#=13 block#=2248264 blocks=1 obj#=166421 tim=12499462851327
WAIT #7: nam='db file sequential read' ela= 2687 file#=13 block#=2250707 blocks=1 obj#=166421 tim=12499462854178
WAIT #7: nam='db file sequential read' ela= 3657 file#=13 block#=2249697 blocks=1 obj#=166421 tim=12499462857896
WAIT #7: nam='db file sequential read' ela= 4139 file#=13 block#=2247074 blocks=1 obj#=166421 tim=12499462862093
WAIT #7: nam='db file sequential read' ela= 4180 file#=47 block#=3649690 blocks=1 obj#=166421 tim=12499509270445
WAIT #7: nam='db file sequential read' ela= 4802 file#=47 block#=3649309 blocks=1 obj#=166421 tim=12499509275327
WAIT #7: nam='db file sequential read' ela= 2459 file#=47 block#=3652697 blocks=1 obj#=166421 tim=12499509277859
WAIT #7: nam='db file sequential read' ela= 4015 file#=47 block#=3652826 blocks=1 obj#=166421 tim=12499509281948
WAIT #7: nam='db file sequential read' ela= 2248 file#=47 block#=3651610 blocks=1 obj#=166421 tim=12499509284269
WAIT #7: nam='db file sequential read' ela= 4824 file#=47 block#=3654297 blocks=1 obj#=166421 tim=12499509289166
WAIT #7: nam='db file sequential read' ela= 2008 file#=47 block#=3652312 blocks=1 obj#=166421 tim=12499509291248
WAIT #7: nam='db file sequential read' ela= 1925 file#=47 block#=3654490 blocks=1 obj#=166421 tim=12499509293246
WAIT #7: nam='db file sequential read' ela= 2859 file#=47 block#=3648458 blocks=1 obj#=166421 tim=12499509296178
WAIT #7: nam='db file sequential read' ela= 1740 file#=47 block#=3648212 blocks=1 obj#=166421 tim=12499509297991
WAIT #7: nam='db file sequential read' ela= 2566 file#=47 block#=3648411 blocks=1 obj#=166421 tim=12499509300631
WAIT #7: nam='db file sequential read' ela= 50772 file#=5 block#=480749 blocks=1 obj#=166421 tim=12499509351477
WAIT #7: nam='db file sequential read' ela= 12928 file#=5 block#=477177 blocks=1 obj#=166421 tim=12499509364482
WAIT #7: nam='db file sequential read' ela= 11116 file#=5 block#=479412 blocks=1 obj#=166421 tim=12499509375672
WAIT #7: nam='db file sequential read' ela= 4803 file#=5 block#=483440 blocks=1 obj#=166421 tim=12499509380549
WAIT #7: nam='db file sequential read' ela= 6900 file#=5 block#=481454 blocks=1 obj#=166421 tim=12499509387522
Received ORADEBUG command 'event 10046 trace name context off' from process Unix process pid: 3983, image:
/u01/app/oracle/admin/SURV2/udump/surv2_ora_1545.trc
Oracle Database 10g Release 10.2.0.4.0 - Production
ORACLE_HOME = /u01/app/oracle/product/10.2.0/db
System name: SunOS
Node name: prdfa001
Release: 5.10
Version: Generic_139556-08
Machine: i86pc
Instance name: SURV2
Redo thread mounted by this instance: 1
Oracle process number: 22
Unix process pid: 1545, image: oracle@prdfa001 (TNS V1-V3)
*** ACTION NAME:() 2010-09-09 23:20:13.485
*** MODULE NAME:(sqlplus@prdfa001 (TNS V1-V3)) 2010-09-09 23:20:13.485
*** SERVICE NAME:(SYS$USERS) 2010-09-09 23:20:13.485
*** SESSION ID:(290.697) 2010-09-09 23:20:13.485
===================================================
SYSTEM STATE
System global information:
processes: base 47819b480, size 300, cleanup 4781a5638
allocation: free sessions 47f1d6148, free calls 0
control alloc errors: 0 (process), 0 (session), 0 (call)
PMON latch cleanup depth: 0
seconds since PMON's last scan for dead processes: 20
system statistics:
1171 logons cumulative
19 logons current
89219 opened cursors cumulative
86 opened cursors current
15095069 user commits
5 user rollbacks
58632904 user calls
44023255 recursive calls
224311 recursive cpu usage
201424173 session logical reads
0 session stored procedure space
901812 CPU used when call started
995437 CPU used by this session
6814196 DB time
0 cluster wait time
22542300822 concurrency wait time
3095 application wait time
16479074661 user I/O wait time
1284052668 session connect time
1284067190 process last non-idle time
189018343568 session uga memory
1249667216 session uga memory max
26059216 messages sent
26059220 messages received
239739 background timeouts
162399896 session pga memory
189662872 session pga memory max
4 enqueue timeouts
901146 enqueue waits
0 enqueue deadlocks
32122711 enqueue requests
17819 enqueue conversions
32122676 enqueue releases
0 global enqueue gets sync
0 global enqueue gets async
0 global enqueue get time
0 global enqueue releases
2865667 physical read total IO requests
262620 physical read total multi block requests
270093476864 physical read total bytes
select SYS_CONTEXT('USERENV', 'SERVER_HOST'), SYS_CONTEXT('USERENV', 'DB_UNIQUE_NAME'), SYS_CONTEXT('USERENV', 'INSTANCE_NAME'), SYS_CONTEXT('USERENV', 'SERVICE_NAME'), INSTANCE_NUMBER, STARTUP_TIME, SYS_CONTEXT('USERENV', 'DB_DOMAIN') from v$instance where INSTANCE_NAME=SYS_CONTEXT('USERENV', 'INSTANCE_NAME')
hash=550c95f3d0cfa8290e60ea8382d3a2ca timestamp=09-09-2010 04:24:19
namespace=CRSR flags=RON/KGHP/TIM/PN0/LRG/KST/DBN/MTX/[100100d1]
kkkk-dddd-llll=0000-0001-0001 lock=N pin=0 latch#=9 hpc=0582 hlc=0582
lwt=47df576e8[47df576e8,47df576e8] ltm=47df576f8[47df576f8,47df576f8]
pwt=47df576b0[47df576b0,47df576b0] ptm=47df576c0[47df576c0,47df576c0]
ref=47df57718[47df57718,47df57718] lnd=47df57730[47df57730,47df57730]
LIBRARY OBJECT: object=471ee1d38
type=CRSR flags=EXS[0001] pflags=[0000] status=VALD load=0
CHILDREN: size=16
child# table reference handle
0 471ee1800 471ee1470 47df7dce0
DATA BLOCKS:
data# heap pointer status pins change whr
0 47df7de48 471ee1e50 I/P/A/-/- 0 NONE 00
SO: 473691d60, type: 53, owner: 47924e810, flag: INIT/-/-/0x00
LIBRARY OBJECT LOCK: lock=473691d60 handle=47bb22fa0 mode=N
call pin=0 session pin=0 hpc=0000 hlc=0000
htl=473691de0[4735dbcb8,476cfbf58] htb=476cfbf58 ssga=476cfb6a0
user=47924e810 session=47f2310f0 count=1 flags=[0000] savepoint=0x0
LIBRARY OBJECT HANDLE: handle=47bb22fa0 mtx=47bb230d0(0) cdp=0
namespace=CRSR flags=RON/KGHP/PN0/EXP/[10010100]
kkkk-dddd-llll=0000-0001-0001 lock=N pin=0 latch#=3 hpc=fd84 hlc=fd84
lwt=47bb23048[47bb23048,47bb23048] ltm=47bb23058[47bb23058,47bb23058]
pwt=47bb23010[47bb23010,47bb23010] ptm=47bb23020[47bb23020,47bb23020]
ref=47bb23078[472f8de18,472f8de18] lnd=47bb23090[47bb23090,47bb23090]
LIBRARY OBJECT: object=472f8d9d8
type=CRSR flags=EXS[0001] pflags=[0000] status=VALD load=0
DEPENDENCIES: count=1 size=16
AUTHORIZATIONS: count=1 size=16 minimum entrysize=16
ACCESSES: count=1 size=16
TRANSLATIONS: count=1 size=16
DATA BLOCKS:
data# heap pointer status pins change whr
0 47bb22ee0 472f8daf0 I/P/A/-/- 0 NONE 00
6 472f8e508 46be86250 I/-/A/-/E 0 NONE 00
SO: 4735dbc38, type: 53, owner: 47924e810, flag: INIT/-/-/0x00
LIBRARY OBJECT LOCK: lock=4735dbc38 handle=47bb231c8 mode=N
call pin=0 session pin=0 hpc=0000 hlc=0000
htl=4735dbcb8[476cfbf58,473691de0] htb=476cfbf58 ssga=476cfb6a0
user=47924e810 session=47f2310f0 count=1 flags=[0000] savepoint=0x4c894f8b
LIBRARY OBJECT HANDLE: handle=47bb231c8 mtx=47bb232f8(1) cdp=1
name=select value$ from props$ where name = 'GLOBAL_DB_NAME'
hash=4bb432d65c5a391a42a5c3fa74472c7a timestamp=09-09-2010 04:24:12
namespace=CRSR flags=RON/KGHP/TIM/PN0/SML/KST/DBN/MTX/[120100d0]
kkkk-dddd-llll=0000-0001-0001 lock=N pin=0 latch#=3 hpc=0584 hlc=0584
lwt=47bb23270[47bb23270,47bb23270] ltm=47bb23280[47bb23280,47bb23280]
pwt=47bb23238[47bb23238,47bb23238] ptm=47bb23248[47bb23248,47bb23248]
ref=47bb232a0[47bb232a0,47bb232a0] lnd=47bb232b8[47bb232b8,47bb232b8]
LIBRARY OBJECT: object=472f8e6e0
type=CRSR flags=EXS[0001] pflags=[0000] status=VALD load=0
CHILDREN: size=16
child# table reference handle
0 472f8e1a8 472f8de18 47bb22fa0
DATA BLOCKS:
data# heap pointer status pins change whr
0 47bb23108 472f8e7f8 I/P/A/-/- 0 NONE 00
SO: 473644348, type: 53, owner: 47924e810, flag: INIT/-/-/0x00
LIBRARY OBJECT LOCK: lock=473644348 handle=47bbde418 mode=N
call pin=0 session pin=0 hpc=0000 hlc=0000
htl=4736443c8[476cfc0b8,476cfc0b8] htb=476cfc0b8 ssga=476cfb6a0
user=47924e810 session=47924e810 count=1 flags=[0000] savepoint=0x4c894f8b
LIBRARY OBJECT HANDLE: handle=47bbde418 mtx=47bbde548(0) cdp=0
name=ALTER SESSION SET TIME_ZONE='+02:00'
hash=3878dff8839e71e3dd05a2e75fbd6390 timestamp=09-09-2010 04:24:04
namespace=CRSR flags=RON/KGHP/TIM/PN0/SML/DBN/[12010040]
kkkk-dddd-llll=0000-0001-0001 lock=N pin=0 latch#=11 hpc=04e8 hlc=04e8
lwt=47bbde4c0[47bbde4c0,47bbde4c0] ltm=47bbde4d0[47bbde4d0,47bbde4d0]
pwt=47bbde488[47bbde488,47bbde488] ptm=47bbde498[47bbde498,47bbde498]
ref=47bbde4f0[47bbde4f0,47bbde4f0] lnd=47bbde508[47bbde508,47bbde508]
LIBRARY OBJECT: object=472fffc08
type=CRSR flags=EXS[0001] pflags=[0000] status=VALD load=0
DATA BLOCKS:
data# heap pointer status pins change whr
0 47bbde320 472fffd20 I/P/A/-/- 0 NONE 00
SO: 47aecf9e8, type: 41, owner: 47924e810, flag: INIT/-/-/0x00
(dummy) nxc=0, nlb=0
SO: 47f290540, type: 11, owner: 4781a7dc0, flag: INIT/-/-/0x00
(broadcast handle) flag: (2) ACTIVE SUBSCRIBER, owner: 4781a7dc0,
event: 1132, last message event: 1132,
last message waited event: 1132, next message: 0(0), messages read: 0
channel: (47a2df4f8) system events broadcast channel
scope: 2, event: 1132, last mesage event: 18,
publishers/subscribers: 0/17,
messages published: 1
SO: 47826b228, type: 3, owner: 4781a7dc0, flag: INIT/-/-/0x00
(call) sess: cur 47924e810, rec 0, usr 47924e810; depth: 0
SO: 476c52968, type: 16, owner: 4781a7dc0, flag: INIT/-/-/0x00
(osp req holder)
PSEUDO PROCESS for group DEFAULT:
SO: 47a1eb7d0, type: 2, owner: 0, flag: INIT/-/-/0x00
(process) Oracle pid=0, calls cur/top: 0/0, flag: (20) PSEUDO
int error: 0, call error: 0, sess error: 0, txn error 0
(post info) last post received: 0 0 0
last post received-location: No post
last process to post me: none
last post sent: 0 0 0
last post sent-location: No post
last process posted by me: none
(latch info) wait_event=0 bits=0
Process Group: DEFAULT, pseudo proc: 47a1eb7d0
O/S info: user: , term: , ospid: (DEAD)
OSD pid info: Unix process pid: 0, image: PSEUDO
Dump of memory from 0x00000004791BF538 to 0x00000004791BF740
4791BF530 00000000 00000000 [........]
4791BF540 00000000 00000000 00000000 00000000 [................]
Repeat 31 times
NO DETACHED BRANCHES.
NO DETACHED NETWORK CONNECTIONS.
CLEANUP STATE OBJECTS:
SO: 47f0cd038, type: 1, owner: 0, flag: INIT/-/-/0x00
(cleanup state object) description: instance enqueue anchor state
latch: 0x380009890
SO: 4782cf080, type: 5, owner: 47f0cd038, flag: INIT/-/-/0x00
(enqueue) TA-00000006-00000001 DID: 0001-000F-0000000B
lv: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 res_flag: 0x2
res: 0x47a28d020, mode: X, lock_flag: 0x0
own: 0x0, sess: 0x0, prv: 0x47a28d030
SO: 47f0cd098, type: 1, owner: 0, flag: INIT/-/-/0x00
(cleanup state object) description: switchable channel handle anch
latch: 0x38000ac98
SO: 47f28f868, type: 11, owner: 47f0cd098, flag: INIT/-/-/0x00
(broadcast handle) flag: (c2) ACTIVE SUBSCRIBER, owner: 0,
event: 1, last message event: 1,
last message waited event: 1, next message: 0(0), messages read: 0
channel: (47a2e4190) KPON channel
scope: 2, event: 1, last mesage event: 0,
publishers/subscribers: 0/1,
messages published: 0
SO: 47f0cd0f8, type: 1, owner: 0, flag: INIT/-/-/0x00
(cleanup state object) description: TT shared object cleanup SO
latch: 0x38001c6b8
SO: 47f0cd158, type: 1, owner: 0, flag: INIT/-/-/0x00
(cleanup state object) description: SS shared object cleanup SO
latch: 0x38001cd48
END OF SYSTEM STATE
Top 5 Timed Events Avg %Total
~~~~~~~~~~~~~~~~~~ wait Call
Event Waits Time (s) (ms) Time Wait Class
db file sequential read 2,347,652 9,215 4 64.5 User I/O
db file scattered read 245,687 4,199 17 29.4 User I/O
CPU time 974 6.8
db file parallel write 50,082 408 8 2.9 System I/O
log file parallel write 6,963 52 7 0.4 System I/O
Time Model Statistics DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> Total time in database user-calls (DB Time): 14286.4s
-> Statistics including the word "background" measure background process
time, and so do not contribute to the DB time statistic
-> Ordered by % or DB time desc, Statistic name
Statistic Name Time (s) % of DB Time
sql execute elapsed time 14,280.3 100.0
DB CPU 974.5 6.8
PL/SQL execution elapsed time 531.8 3.7
parse time elapsed 30.5 .2
hard parse elapsed time 27.1 .2
connection management call elapsed time 14.9 .1
hard parse (sharing criteria) elapsed time 3.4 .0
hard parse (bind mismatch) elapsed time 3.1 .0
PL/SQL compilation elapsed time 2.4 .0
failed parse elapsed time 0.0 .0
repeated bind elapsed time 0.0 .0
sequence load elapsed time 0.0 .0
DB time 14,286.4 N/A
background elapsed time 670.2 N/A
background cpu time 186.1 N/A
Wait Class DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> s - second
-> cs - centisecond - 100th of a second
-> ms - millisecond - 1000th of a second
-> us - microsecond - 1000000th of a second
-> ordered by wait time desc, waits desc
Avg
%Time Total Wait wait Waits
Wait Class Waits -outs Time (s) (ms) /txn
User I/O 2,593,484 .0 13,415 5 150.0
System I/O 87,506 .0 515 6 5.1
Other 839 11.4 6 7 0.0
Commit 3,225 .1 6 2 0.2
Concurrency 1,033 .0 5 5 0.1
Configuration 2,514 99.4 0 0 0.1
Network 47,559 .0 0 0 2.8
Application 7 .0 0 0 0.0
Wait Events DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> s - second
-> cs - centisecond - 100th of a second
-> ms - millisecond - 1000th of a second
-> us - microsecond - 1000000th of a second
-> ordered by wait time desc, waits desc (idle events last)
Avg
%Time Total Wait wait Waits
Event Waits -outs Time (s) (ms) /txn
db file sequential read 2,347,652 .0 9,215 4 135.8
db file scattered read 245,687 .0 4,199 17 14.2
db file parallel write 50,082 .0 408 8 2.9
log file parallel write 6,963 .0 52 7 0.4
control file parallel write 6,203 .0 44 7 0.4
control file sequential read 24,242 .0 11 0 1.4
log file sync 3,225 .1 6 2 0.2
latch free 84 .0 4 47 0.0
os thread startup 25 .0 3 120 0.0
latch: session allocation 39 .0 1 33 0.0
db file parallel read 12 .0 1 92 0.0
enq: TX - index contention 186 .0 1 3 0.0
latch: shared pool 47 .0 1 11 0.0
LGWR wait for redo copy 319 3.1 0 1 0.0
library cache load lock 2 .0 0 172 0.0
buffer busy waits 590 .0 0 0 0.0
log file switch completion 6 .0 0 29 0.0
SGA: allocation forcing comp 11 54.5 0 14 0.0
latch: library cache lock 50 .0 0 3 0.0
read by other session 38 .0 0 4 0.0
direct path read 42 .0 0 3 0.0
SQL*Net message to client 44,807 .0 0 0 2.6
rdbms ipc reply 207 .0 0 0 0.0
SQL*Net more data from clien 1,014 .0 0 0 0.1
latch: cache buffers chains 24 .0 0 1 0.0
latch: library cache 29 .0 0 1 0.0
log file sequential read 8 .0 0 3 0.0
direct path write 50 .0 0 0 0.0
SQL*Net more data to client 398 .0 0 0 0.0
latch: object queue header o 12 .0 0 1 0.0
latch: In memory undo latch 78 .0 0 0 0.0
undo segment extension 2,507 99.7 0 0 0.1
latch: cache buffers lru cha 4 .0 0 1 0.0
log file single write 8 .0 0 0 0.0
local write wait 3 .0 0 1 0.0
enq: RO - fast object reuse 3 .0 0 1 0.0
buffer deadlock 87 92.0 0 0 0.0
enq: JS - queue lock 1 .0 0 1 0.0
cursor: pin S 70 .0 0 0 0.0
latch: row cache objects 2 .0 0 1 0.0
SQL*Net message to dblink 1,338 .0 0 0 0.1
latch: checkpoint queue latc 2 .0 0 0 0.0
reliable message 3 .0 0 0 0.0
log buffer space 1 .0 0 1 0.0
SQL*Net break/reset to clien 4 .0 0 0 0.0
SQL*Net more data from dblin 2 .0 0 0 0.0
SQL*Net message from client 44,949 .0 155,701 3464 2.6
virtual circuit status 621 100.0 18,156 29237 0.0
Streams AQ: qmn slave idle w 664 .0 18,127 27299 0.0
Streams AQ: qmn coordinator 1,339 50.4 18,099 13517 0.1
Streams AQ: waiting for time 12 100.0 8,741 728394 0.0
jobq slave wait 130 100.0 380 2927 0.0
PL/SQL lock timer 1 100.0 1 978 0.0
SQL*Net message from dblink 1,338 .0 0 0 0.1
single-task message 1 .0 0 38 0.0
class slave wait 11 .0 0 1 0.0
SQL ordered by Elapsed Time DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> Resources reported for PL/SQL code includes the resources used by all SQL
statements called by the code.
-> % Total DB Time is the Elapsed Time of the SQL statement divided
into the Total Database Time multiplied by 100
Elapsed CPU Elap per % Total
Time (s) Time (s) Executions Exec (s) DB Time SQL Id
13,664 906 0 N/A 95.6 gr2cx6athc5j5
Module: SQL*Plus
BEGIN DBMS_OUTPUT.PUT_LINE(equiduct.eod(NULL,NULL)); END;
8,792 195 0 N/A 61.5 986fzxtzr52u5
Module: SQL*Plus
UPDATE TIBEX_ORDER SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"SYS_B_1"
2,524 368 1 2524.1 17.7 c4uf0x6hdgnwq
Module: SQL*Plus
UPDATE TIBEX_FIXSESSIONSTATE SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"
SYS_B_1"
1,414 177 1 1414.4 9.9 cbg09ma34kq8w
Module: SQL*Plus
SELECT count(*) FROM TIBEX_ORDER WHERE INSTRUMENTID=:"SYS_B_0"
742 137 1 742.2 5.2 g0sg6v994wssq
Module: SQL*Plus
SELECT count(*) FROM TIBEX_FIXSESSIONSTATE WHERE INSTRUMENTID=:"SYS_B_0"
274 11 1 274.2 1.9 6mcpb06rctk0x
Module: DBMS_SCHEDULER
call dbms_space.auto_space_advisor_job_proc ( )
264 8 27 9.8 1.8 8szmwam7fysa3
Module: DBMS_SCHEDULER
insert into wri$_adv_objspace_trend_data select timepoint, space_usage, space_a
lloc, quality from table(dbms_space.object_growth_trend(:1, :2, :3, :4, NULL, N
ULL, NULL, 'FALSE', :5, 'FALSE'))
99 1 1 99.4 0.7 1z0x41f66nvjr
Module: SQL*Plus
UPDATE TIBEX_INSTRUMENTADMIN SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"
SYS_B_1"
21 10 1 21.5 0.2 bbc1ck8594kvj
Module: SQL*Plus
UPDATE TIBEX_INSTRUMENTDAILYHIST SET ADJOPEN=NVL(ADJOPEN,OPEN), ADJHIGH=NVL(ADJH
IGH,HIGH), ADJLOW=NVL(ADJLOW,LOW), ADJMID=NVL(ADJMID,MID), ADJCLOSE=NVL(ADJCLOSE
,CLOSE), ADJVOLUME=NVL(ADJVOLUME,VOLUME), ADJCLOSINGBID=NVL(ADJCLOSINGBID,CLOSIN
GBID), ADJCLOSINGOFFER=NVL(ADJCLOSINGOFFER,CLOSINGOFFER)
12 0 1 12.5 0.1 6xm9p9uy5kaap
Module: SQL*Plus
SELECT count(*) FROM TIBEX_INSTRUMENTSTATE WHERE INSTRUMENTID=:"SYS_B_0"
SQL ordered by CPU Time DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> Resources reported for PL/SQL code includes the resources used by all SQL
statements called by the code.
-> % Total DB Time is the Elapsed Time of the SQL statement divided
into the Total Database Time multiplied by 100
CPU Elapsed CPU per % Total
Time (s) Time (s) Executions Exec (s) DB Time SQL Id
906 13,664 0 N/A 95.6 gr2cx6athc5j5
Module: SQL*Plus
BEGIN DBMS_OUTPUT.PUT_LINE(equiduct.eod(NULL,NULL)); END;
368 2,524 1 367.51 17.7 c4uf0x6hdgnwq
Module: SQL*Plus
UPDATE TIBEX_FIXSESSIONSTATE SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"
SYS_B_1"
195 8,792 0 N/A 61.5 986fzxtzr52u5
Module: SQL*Plus
UPDATE TIBEX_ORDER SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"SYS_B_1"
177 1,414 1 176.93 9.9 cbg09ma34kq8w
Module: SQL*Plus
SELECT count(*) FROM TIBEX_ORDER WHERE INSTRUMENTID=:"SYS_B_0"
137 742 1 137.38 5.2 g0sg6v994wssq
Module: SQL*Plus
SELECT count(*) FROM TIBEX_FIXSESSIONSTATE WHERE INSTRUMENTID=:"SYS_B_0"
11 274 1 10.82 1.9 6mcpb06rctk0x
Module: DBMS_SCHEDULER
call dbms_space.auto_space_advisor_job_proc ( )
10 21 1 9.65 0.2 bbc1ck8594kvjEdited by: NM on 10-Sep-2010 07:39Hi,
Last night we had issue with one of the prod server where we updating one of table which contains large number records in millions.Same identical machine completed in1 hour and other box never completed but doing db file sequential read but in the long ops the last statement it was done 20:16 after that nothing is happening but i ran few trace on that user.
/u01/app/oracle/admin/SURV2/udump/surv2_ora_10048.trc
Oracle Database 10g Release 10.2.0.4.0 - Production
ORACLE_HOME = /u01/app/oracle/product/10.2.0/db
System name: SunOS
Node name: prdfa001
Release: 5.10
Version: Generic_139556-08
Machine: i86pc
Instance name: SURV2
Redo thread mounted by this instance: 1
Oracle process number: 18
Unix process pid: 10048, image: oracle@prdfa001
*** 2010-09-09 23:37:07.484
*** ACTION NAME:() 2010-09-09 23:37:07.473
*** MODULE NAME:(SQL*Plus) 2010-09-09 23:37:07.473
*** SERVICE NAME:(SURV2) 2010-09-09 23:37:07.473
*** SESSION ID:(289.54) 2010-09-09 23:37:07.473
Received ORADEBUG command 'unlimit' from process Unix process pid: 3983, image:
*** 2010-09-09 23:37:20.315
Received ORADEBUG command 'event 10046 trace name context forever, level 12' from process Unix process pid: 3983, image:
WAIT #7: nam='db file sequential read' ela= 11160 file#=13 block#=2252349 blocks=1 obj#=166421 tim=12499462835161
WAIT #7: nam='db file sequential read' ela= 2857 file#=13 block#=2249751 blocks=1 obj#=166421 tim=12499462838137
WAIT #7: nam='db file sequential read' ela= 3810 file#=13 block#=2251361 blocks=1 obj#=166421 tim=12499462842048
WAIT #7: nam='db file sequential read' ela= 4459 file#=13 block#=2247059 blocks=1 obj#=166421 tim=12499462846564
WAIT #7: nam='db file sequential read' ela= 2841 file#=13 block#=2247507 blocks=1 obj#=166421 tim=12499462849468
WAIT #7: nam='db file sequential read' ela= 427 file#=13 block#=2247568 blocks=1 obj#=166421 tim=12499462850032
WAIT #7: nam='db file sequential read' ela= 1187 file#=13 block#=2248264 blocks=1 obj#=166421 tim=12499462851327
WAIT #7: nam='db file sequential read' ela= 2687 file#=13 block#=2250707 blocks=1 obj#=166421 tim=12499462854178
WAIT #7: nam='db file sequential read' ela= 3657 file#=13 block#=2249697 blocks=1 obj#=166421 tim=12499462857896
WAIT #7: nam='db file sequential read' ela= 4139 file#=13 block#=2247074 blocks=1 obj#=166421 tim=12499462862093
WAIT #7: nam='db file sequential read' ela= 4180 file#=47 block#=3649690 blocks=1 obj#=166421 tim=12499509270445
WAIT #7: nam='db file sequential read' ela= 4802 file#=47 block#=3649309 blocks=1 obj#=166421 tim=12499509275327
WAIT #7: nam='db file sequential read' ela= 2459 file#=47 block#=3652697 blocks=1 obj#=166421 tim=12499509277859
WAIT #7: nam='db file sequential read' ela= 4015 file#=47 block#=3652826 blocks=1 obj#=166421 tim=12499509281948
WAIT #7: nam='db file sequential read' ela= 2248 file#=47 block#=3651610 blocks=1 obj#=166421 tim=12499509284269
WAIT #7: nam='db file sequential read' ela= 4824 file#=47 block#=3654297 blocks=1 obj#=166421 tim=12499509289166
WAIT #7: nam='db file sequential read' ela= 2008 file#=47 block#=3652312 blocks=1 obj#=166421 tim=12499509291248
WAIT #7: nam='db file sequential read' ela= 1925 file#=47 block#=3654490 blocks=1 obj#=166421 tim=12499509293246
WAIT #7: nam='db file sequential read' ela= 2859 file#=47 block#=3648458 blocks=1 obj#=166421 tim=12499509296178
WAIT #7: nam='db file sequential read' ela= 1740 file#=47 block#=3648212 blocks=1 obj#=166421 tim=12499509297991
WAIT #7: nam='db file sequential read' ela= 2566 file#=47 block#=3648411 blocks=1 obj#=166421 tim=12499509300631
WAIT #7: nam='db file sequential read' ela= 50772 file#=5 block#=480749 blocks=1 obj#=166421 tim=12499509351477
WAIT #7: nam='db file sequential read' ela= 12928 file#=5 block#=477177 blocks=1 obj#=166421 tim=12499509364482
WAIT #7: nam='db file sequential read' ela= 11116 file#=5 block#=479412 blocks=1 obj#=166421 tim=12499509375672
WAIT #7: nam='db file sequential read' ela= 4803 file#=5 block#=483440 blocks=1 obj#=166421 tim=12499509380549
WAIT #7: nam='db file sequential read' ela= 6900 file#=5 block#=481454 blocks=1 obj#=166421 tim=12499509387522
Received ORADEBUG command 'event 10046 trace name context off' from process Unix process pid: 3983, image:
/u01/app/oracle/admin/SURV2/udump/surv2_ora_1545.trc
Oracle Database 10g Release 10.2.0.4.0 - Production
ORACLE_HOME = /u01/app/oracle/product/10.2.0/db
System name: SunOS
Node name: prdfa001
Release: 5.10
Version: Generic_139556-08
Machine: i86pc
Instance name: SURV2
Redo thread mounted by this instance: 1
Oracle process number: 22
Unix process pid: 1545, image: oracle@prdfa001 (TNS V1-V3)
*** ACTION NAME:() 2010-09-09 23:20:13.485
*** MODULE NAME:(sqlplus@prdfa001 (TNS V1-V3)) 2010-09-09 23:20:13.485
*** SERVICE NAME:(SYS$USERS) 2010-09-09 23:20:13.485
*** SESSION ID:(290.697) 2010-09-09 23:20:13.485
===================================================
SYSTEM STATE
System global information:
processes: base 47819b480, size 300, cleanup 4781a5638
allocation: free sessions 47f1d6148, free calls 0
control alloc errors: 0 (process), 0 (session), 0 (call)
PMON latch cleanup depth: 0
seconds since PMON's last scan for dead processes: 20
system statistics:
1171 logons cumulative
19 logons current
89219 opened cursors cumulative
86 opened cursors current
15095069 user commits
5 user rollbacks
58632904 user calls
44023255 recursive calls
224311 recursive cpu usage
201424173 session logical reads
0 session stored procedure space
901812 CPU used when call started
995437 CPU used by this session
6814196 DB time
0 cluster wait time
22542300822 concurrency wait time
3095 application wait time
16479074661 user I/O wait time
1284052668 session connect time
1284067190 process last non-idle time
189018343568 session uga memory
1249667216 session uga memory max
26059216 messages sent
26059220 messages received
239739 background timeouts
162399896 session pga memory
189662872 session pga memory max
4 enqueue timeouts
901146 enqueue waits
0 enqueue deadlocks
32122711 enqueue requests
17819 enqueue conversions
32122676 enqueue releases
0 global enqueue gets sync
0 global enqueue gets async
0 global enqueue get time
0 global enqueue releases
2865667 physical read total IO requests
262620 physical read total multi block requests
270093476864 physical read total bytes
select SYS_CONTEXT('USERENV', 'SERVER_HOST'), SYS_CONTEXT('USERENV', 'DB_UNIQUE_NAME'), SYS_CONTEXT('USERENV', 'INSTANCE_NAME'), SYS_CONTEXT('USERENV', 'SERVICE_NAME'), INSTANCE_NUMBER, STARTUP_TIME, SYS_CONTEXT('USERENV', 'DB_DOMAIN') from v$instance where INSTANCE_NAME=SYS_CONTEXT('USERENV', 'INSTANCE_NAME')
hash=550c95f3d0cfa8290e60ea8382d3a2ca timestamp=09-09-2010 04:24:19
namespace=CRSR flags=RON/KGHP/TIM/PN0/LRG/KST/DBN/MTX/[100100d1]
kkkk-dddd-llll=0000-0001-0001 lock=N pin=0 latch#=9 hpc=0582 hlc=0582
lwt=47df576e8[47df576e8,47df576e8] ltm=47df576f8[47df576f8,47df576f8]
pwt=47df576b0[47df576b0,47df576b0] ptm=47df576c0[47df576c0,47df576c0]
ref=47df57718[47df57718,47df57718] lnd=47df57730[47df57730,47df57730]
LIBRARY OBJECT: object=471ee1d38
type=CRSR flags=EXS[0001] pflags=[0000] status=VALD load=0
CHILDREN: size=16
child# table reference handle
0 471ee1800 471ee1470 47df7dce0
DATA BLOCKS:
data# heap pointer status pins change whr
0 47df7de48 471ee1e50 I/P/A/-/- 0 NONE 00
SO: 473691d60, type: 53, owner: 47924e810, flag: INIT/-/-/0x00
LIBRARY OBJECT LOCK: lock=473691d60 handle=47bb22fa0 mode=N
call pin=0 session pin=0 hpc=0000 hlc=0000
htl=473691de0[4735dbcb8,476cfbf58] htb=476cfbf58 ssga=476cfb6a0
user=47924e810 session=47f2310f0 count=1 flags=[0000] savepoint=0x0
LIBRARY OBJECT HANDLE: handle=47bb22fa0 mtx=47bb230d0(0) cdp=0
namespace=CRSR flags=RON/KGHP/PN0/EXP/[10010100]
kkkk-dddd-llll=0000-0001-0001 lock=N pin=0 latch#=3 hpc=fd84 hlc=fd84
lwt=47bb23048[47bb23048,47bb23048] ltm=47bb23058[47bb23058,47bb23058]
pwt=47bb23010[47bb23010,47bb23010] ptm=47bb23020[47bb23020,47bb23020]
ref=47bb23078[472f8de18,472f8de18] lnd=47bb23090[47bb23090,47bb23090]
LIBRARY OBJECT: object=472f8d9d8
type=CRSR flags=EXS[0001] pflags=[0000] status=VALD load=0
DEPENDENCIES: count=1 size=16
AUTHORIZATIONS: count=1 size=16 minimum entrysize=16
ACCESSES: count=1 size=16
TRANSLATIONS: count=1 size=16
DATA BLOCKS:
data# heap pointer status pins change whr
0 47bb22ee0 472f8daf0 I/P/A/-/- 0 NONE 00
6 472f8e508 46be86250 I/-/A/-/E 0 NONE 00
SO: 4735dbc38, type: 53, owner: 47924e810, flag: INIT/-/-/0x00
LIBRARY OBJECT LOCK: lock=4735dbc38 handle=47bb231c8 mode=N
call pin=0 session pin=0 hpc=0000 hlc=0000
htl=4735dbcb8[476cfbf58,473691de0] htb=476cfbf58 ssga=476cfb6a0
user=47924e810 session=47f2310f0 count=1 flags=[0000] savepoint=0x4c894f8b
LIBRARY OBJECT HANDLE: handle=47bb231c8 mtx=47bb232f8(1) cdp=1
name=select value$ from props$ where name = 'GLOBAL_DB_NAME'
hash=4bb432d65c5a391a42a5c3fa74472c7a timestamp=09-09-2010 04:24:12
namespace=CRSR flags=RON/KGHP/TIM/PN0/SML/KST/DBN/MTX/[120100d0]
kkkk-dddd-llll=0000-0001-0001 lock=N pin=0 latch#=3 hpc=0584 hlc=0584
lwt=47bb23270[47bb23270,47bb23270] ltm=47bb23280[47bb23280,47bb23280]
pwt=47bb23238[47bb23238,47bb23238] ptm=47bb23248[47bb23248,47bb23248]
ref=47bb232a0[47bb232a0,47bb232a0] lnd=47bb232b8[47bb232b8,47bb232b8]
LIBRARY OBJECT: object=472f8e6e0
type=CRSR flags=EXS[0001] pflags=[0000] status=VALD load=0
CHILDREN: size=16
child# table reference handle
0 472f8e1a8 472f8de18 47bb22fa0
DATA BLOCKS:
data# heap pointer status pins change whr
0 47bb23108 472f8e7f8 I/P/A/-/- 0 NONE 00
SO: 473644348, type: 53, owner: 47924e810, flag: INIT/-/-/0x00
LIBRARY OBJECT LOCK: lock=473644348 handle=47bbde418 mode=N
call pin=0 session pin=0 hpc=0000 hlc=0000
htl=4736443c8[476cfc0b8,476cfc0b8] htb=476cfc0b8 ssga=476cfb6a0
user=47924e810 session=47924e810 count=1 flags=[0000] savepoint=0x4c894f8b
LIBRARY OBJECT HANDLE: handle=47bbde418 mtx=47bbde548(0) cdp=0
name=ALTER SESSION SET TIME_ZONE='+02:00'
hash=3878dff8839e71e3dd05a2e75fbd6390 timestamp=09-09-2010 04:24:04
namespace=CRSR flags=RON/KGHP/TIM/PN0/SML/DBN/[12010040]
kkkk-dddd-llll=0000-0001-0001 lock=N pin=0 latch#=11 hpc=04e8 hlc=04e8
lwt=47bbde4c0[47bbde4c0,47bbde4c0] ltm=47bbde4d0[47bbde4d0,47bbde4d0]
pwt=47bbde488[47bbde488,47bbde488] ptm=47bbde498[47bbde498,47bbde498]
ref=47bbde4f0[47bbde4f0,47bbde4f0] lnd=47bbde508[47bbde508,47bbde508]
LIBRARY OBJECT: object=472fffc08
type=CRSR flags=EXS[0001] pflags=[0000] status=VALD load=0
DATA BLOCKS:
data# heap pointer status pins change whr
0 47bbde320 472fffd20 I/P/A/-/- 0 NONE 00
SO: 47aecf9e8, type: 41, owner: 47924e810, flag: INIT/-/-/0x00
(dummy) nxc=0, nlb=0
SO: 47f290540, type: 11, owner: 4781a7dc0, flag: INIT/-/-/0x00
(broadcast handle) flag: (2) ACTIVE SUBSCRIBER, owner: 4781a7dc0,
event: 1132, last message event: 1132,
last message waited event: 1132, next message: 0(0), messages read: 0
channel: (47a2df4f8) system events broadcast channel
scope: 2, event: 1132, last mesage event: 18,
publishers/subscribers: 0/17,
messages published: 1
SO: 47826b228, type: 3, owner: 4781a7dc0, flag: INIT/-/-/0x00
(call) sess: cur 47924e810, rec 0, usr 47924e810; depth: 0
SO: 476c52968, type: 16, owner: 4781a7dc0, flag: INIT/-/-/0x00
(osp req holder)
PSEUDO PROCESS for group DEFAULT:
SO: 47a1eb7d0, type: 2, owner: 0, flag: INIT/-/-/0x00
(process) Oracle pid=0, calls cur/top: 0/0, flag: (20) PSEUDO
int error: 0, call error: 0, sess error: 0, txn error 0
(post info) last post received: 0 0 0
last post received-location: No post
last process to post me: none
last post sent: 0 0 0
last post sent-location: No post
last process posted by me: none
(latch info) wait_event=0 bits=0
Process Group: DEFAULT, pseudo proc: 47a1eb7d0
O/S info: user: , term: , ospid: (DEAD)
OSD pid info: Unix process pid: 0, image: PSEUDO
Dump of memory from 0x00000004791BF538 to 0x00000004791BF740
4791BF530 00000000 00000000 [........]
4791BF540 00000000 00000000 00000000 00000000 [................]
Repeat 31 times
NO DETACHED BRANCHES.
NO DETACHED NETWORK CONNECTIONS.
CLEANUP STATE OBJECTS:
SO: 47f0cd038, type: 1, owner: 0, flag: INIT/-/-/0x00
(cleanup state object) description: instance enqueue anchor state
latch: 0x380009890
SO: 4782cf080, type: 5, owner: 47f0cd038, flag: INIT/-/-/0x00
(enqueue) TA-00000006-00000001 DID: 0001-000F-0000000B
lv: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 res_flag: 0x2
res: 0x47a28d020, mode: X, lock_flag: 0x0
own: 0x0, sess: 0x0, prv: 0x47a28d030
SO: 47f0cd098, type: 1, owner: 0, flag: INIT/-/-/0x00
(cleanup state object) description: switchable channel handle anch
latch: 0x38000ac98
SO: 47f28f868, type: 11, owner: 47f0cd098, flag: INIT/-/-/0x00
(broadcast handle) flag: (c2) ACTIVE SUBSCRIBER, owner: 0,
event: 1, last message event: 1,
last message waited event: 1, next message: 0(0), messages read: 0
channel: (47a2e4190) KPON channel
scope: 2, event: 1, last mesage event: 0,
publishers/subscribers: 0/1,
messages published: 0
SO: 47f0cd0f8, type: 1, owner: 0, flag: INIT/-/-/0x00
(cleanup state object) description: TT shared object cleanup SO
latch: 0x38001c6b8
SO: 47f0cd158, type: 1, owner: 0, flag: INIT/-/-/0x00
(cleanup state object) description: SS shared object cleanup SO
latch: 0x38001cd48
END OF SYSTEM STATE
Top 5 Timed Events Avg %Total
~~~~~~~~~~~~~~~~~~ wait Call
Event Waits Time (s) (ms) Time Wait Class
db file sequential read 2,347,652 9,215 4 64.5 User I/O
db file scattered read 245,687 4,199 17 29.4 User I/O
CPU time 974 6.8
db file parallel write 50,082 408 8 2.9 System I/O
log file parallel write 6,963 52 7 0.4 System I/O
Time Model Statistics DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> Total time in database user-calls (DB Time): 14286.4s
-> Statistics including the word "background" measure background process
time, and so do not contribute to the DB time statistic
-> Ordered by % or DB time desc, Statistic name
Statistic Name Time (s) % of DB Time
sql execute elapsed time 14,280.3 100.0
DB CPU 974.5 6.8
PL/SQL execution elapsed time 531.8 3.7
parse time elapsed 30.5 .2
hard parse elapsed time 27.1 .2
connection management call elapsed time 14.9 .1
hard parse (sharing criteria) elapsed time 3.4 .0
hard parse (bind mismatch) elapsed time 3.1 .0
PL/SQL compilation elapsed time 2.4 .0
failed parse elapsed time 0.0 .0
repeated bind elapsed time 0.0 .0
sequence load elapsed time 0.0 .0
DB time 14,286.4 N/A
background elapsed time 670.2 N/A
background cpu time 186.1 N/A
Wait Class DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> s - second
-> cs - centisecond - 100th of a second
-> ms - millisecond - 1000th of a second
-> us - microsecond - 1000000th of a second
-> ordered by wait time desc, waits desc
Avg
%Time Total Wait wait Waits
Wait Class Waits -outs Time (s) (ms) /txn
User I/O 2,593,484 .0 13,415 5 150.0
System I/O 87,506 .0 515 6 5.1
Other 839 11.4 6 7 0.0
Commit 3,225 .1 6 2 0.2
Concurrency 1,033 .0 5 5 0.1
Configuration 2,514 99.4 0 0 0.1
Network 47,559 .0 0 0 2.8
Application 7 .0 0 0 0.0
Wait Events DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> s - second
-> cs - centisecond - 100th of a second
-> ms - millisecond - 1000th of a second
-> us - microsecond - 1000000th of a second
-> ordered by wait time desc, waits desc (idle events last)
Avg
%Time Total Wait wait Waits
Event Waits -outs Time (s) (ms) /txn
db file sequential read 2,347,652 .0 9,215 4 135.8
db file scattered read 245,687 .0 4,199 17 14.2
db file parallel write 50,082 .0 408 8 2.9
log file parallel write 6,963 .0 52 7 0.4
control file parallel write 6,203 .0 44 7 0.4
control file sequential read 24,242 .0 11 0 1.4
log file sync 3,225 .1 6 2 0.2
latch free 84 .0 4 47 0.0
os thread startup 25 .0 3 120 0.0
latch: session allocation 39 .0 1 33 0.0
db file parallel read 12 .0 1 92 0.0
enq: TX - index contention 186 .0 1 3 0.0
latch: shared pool 47 .0 1 11 0.0
LGWR wait for redo copy 319 3.1 0 1 0.0
library cache load lock 2 .0 0 172 0.0
buffer busy waits 590 .0 0 0 0.0
log file switch completion 6 .0 0 29 0.0
SGA: allocation forcing comp 11 54.5 0 14 0.0
latch: library cache lock 50 .0 0 3 0.0
read by other session 38 .0 0 4 0.0
direct path read 42 .0 0 3 0.0
SQL*Net message to client 44,807 .0 0 0 2.6
rdbms ipc reply 207 .0 0 0 0.0
SQL*Net more data from clien 1,014 .0 0 0 0.1
latch: cache buffers chains 24 .0 0 1 0.0
latch: library cache 29 .0 0 1 0.0
log file sequential read 8 .0 0 3 0.0
direct path write 50 .0 0 0 0.0
SQL*Net more data to client 398 .0 0 0 0.0
latch: object queue header o 12 .0 0 1 0.0
latch: In memory undo latch 78 .0 0 0 0.0
undo segment extension 2,507 99.7 0 0 0.1
latch: cache buffers lru cha 4 .0 0 1 0.0
log file single write 8 .0 0 0 0.0
local write wait 3 .0 0 1 0.0
enq: RO - fast object reuse 3 .0 0 1 0.0
buffer deadlock 87 92.0 0 0 0.0
enq: JS - queue lock 1 .0 0 1 0.0
cursor: pin S 70 .0 0 0 0.0
latch: row cache objects 2 .0 0 1 0.0
SQL*Net message to dblink 1,338 .0 0 0 0.1
latch: checkpoint queue latc 2 .0 0 0 0.0
reliable message 3 .0 0 0 0.0
log buffer space 1 .0 0 1 0.0
SQL*Net break/reset to clien 4 .0 0 0 0.0
SQL*Net more data from dblin 2 .0 0 0 0.0
SQL*Net message from client 44,949 .0 155,701 3464 2.6
virtual circuit status 621 100.0 18,156 29237 0.0
Streams AQ: qmn slave idle w 664 .0 18,127 27299 0.0
Streams AQ: qmn coordinator 1,339 50.4 18,099 13517 0.1
Streams AQ: waiting for time 12 100.0 8,741 728394 0.0
jobq slave wait 130 100.0 380 2927 0.0
PL/SQL lock timer 1 100.0 1 978 0.0
SQL*Net message from dblink 1,338 .0 0 0 0.1
single-task message 1 .0 0 38 0.0
class slave wait 11 .0 0 1 0.0
SQL ordered by Elapsed Time DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> Resources reported for PL/SQL code includes the resources used by all SQL
statements called by the code.
-> % Total DB Time is the Elapsed Time of the SQL statement divided
into the Total Database Time multiplied by 100
Elapsed CPU Elap per % Total
Time (s) Time (s) Executions Exec (s) DB Time SQL Id
13,664 906 0 N/A 95.6 gr2cx6athc5j5
Module: SQL*Plus
BEGIN DBMS_OUTPUT.PUT_LINE(equiduct.eod(NULL,NULL)); END;
8,792 195 0 N/A 61.5 986fzxtzr52u5
Module: SQL*Plus
UPDATE TIBEX_ORDER SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"SYS_B_1"
2,524 368 1 2524.1 17.7 c4uf0x6hdgnwq
Module: SQL*Plus
UPDATE TIBEX_FIXSESSIONSTATE SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"
SYS_B_1"
1,414 177 1 1414.4 9.9 cbg09ma34kq8w
Module: SQL*Plus
SELECT count(*) FROM TIBEX_ORDER WHERE INSTRUMENTID=:"SYS_B_0"
742 137 1 742.2 5.2 g0sg6v994wssq
Module: SQL*Plus
SELECT count(*) FROM TIBEX_FIXSESSIONSTATE WHERE INSTRUMENTID=:"SYS_B_0"
274 11 1 274.2 1.9 6mcpb06rctk0x
Module: DBMS_SCHEDULER
call dbms_space.auto_space_advisor_job_proc ( )
264 8 27 9.8 1.8 8szmwam7fysa3
Module: DBMS_SCHEDULER
insert into wri$_adv_objspace_trend_data select timepoint, space_usage, space_a
lloc, quality from table(dbms_space.object_growth_trend(:1, :2, :3, :4, NULL, N
ULL, NULL, 'FALSE', :5, 'FALSE'))
99 1 1 99.4 0.7 1z0x41f66nvjr
Module: SQL*Plus
UPDATE TIBEX_INSTRUMENTADMIN SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"
SYS_B_1"
21 10 1 21.5 0.2 bbc1ck8594kvj
Module: SQL*Plus
UPDATE TIBEX_INSTRUMENTDAILYHIST SET ADJOPEN=NVL(ADJOPEN,OPEN), ADJHIGH=NVL(ADJH
IGH,HIGH), ADJLOW=NVL(ADJLOW,LOW), ADJMID=NVL(ADJMID,MID), ADJCLOSE=NVL(ADJCLOSE
,CLOSE), ADJVOLUME=NVL(ADJVOLUME,VOLUME), ADJCLOSINGBID=NVL(ADJCLOSINGBID,CLOSIN
GBID), ADJCLOSINGOFFER=NVL(ADJCLOSINGOFFER,CLOSINGOFFER)
12 0 1 12.5 0.1 6xm9p9uy5kaap
Module: SQL*Plus
SELECT count(*) FROM TIBEX_INSTRUMENTSTATE WHERE INSTRUMENTID=:"SYS_B_0"
SQL ordered by CPU Time DB/Inst: SURV2/SURV2 Snaps: 19172-19178
-> Resources reported for PL/SQL code includes the resources used by all SQL
statements called by the code.
-> % Total DB Time is the Elapsed Time of the SQL statement divided
into the Total Database Time multiplied by 100
CPU Elapsed CPU per % Total
Time (s) Time (s) Executions Exec (s) DB Time SQL Id
906 13,664 0 N/A 95.6 gr2cx6athc5j5
Module: SQL*Plus
BEGIN DBMS_OUTPUT.PUT_LINE(equiduct.eod(NULL,NULL)); END;
368 2,524 1 367.51 17.7 c4uf0x6hdgnwq
Module: SQL*Plus
UPDATE TIBEX_FIXSESSIONSTATE SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"
SYS_B_1"
195 8,792 0 N/A 61.5 986fzxtzr52u5
Module: SQL*Plus
UPDATE TIBEX_ORDER SET INSTRUMENTID=:"SYS_B_0" WHERE INSTRUMENTID=:"SYS_B_1"
177 1,414 1 176.93 9.9 cbg09ma34kq8w
Module: SQL*Plus
SELECT count(*) FROM TIBEX_ORDER WHERE INSTRUMENTID=:"SYS_B_0"
137 742 1 137.38 5.2 g0sg6v994wssq
Module: SQL*Plus
SELECT count(*) FROM TIBEX_FIXSESSIONSTATE WHERE INSTRUMENTID=:"SYS_B_0"
11 274 1 10.82 1.9 6mcpb06rctk0x
Module: DBMS_SCHEDULER
call dbms_space.auto_space_advisor_job_proc ( )
10 21 1 9.65 0.2 bbc1ck8594kvjEdited by: NM on 10-Sep-2010 07:39 -
Control File Sequential Read in 11.2
Hi to all,
i'm in 11.2 database and i'm looking an awr report.
Time:
Begin Snap: 9642 31-Gen-12 16:00:26 51 2.5
End Snap: 9643 31-Gen-12 16:40:27 52 2.6 This is my load profile:
Load Profile Per Second Per Transaction Per Exec Per Call
~~~~~~~~~~~~ --------------- --------------- ---------- ----------
DB Time(s): 0.2 0.3 0.01 0.02
DB CPU(s): 0.1 0.1 0.00 0.01
Redo size: 2,989.8 4,490.0
Logical reads: 1,823.2 2,738.1and this is the wait:
Top 5 Timed Foreground Events
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Avg
wait % DB
Event Waits Time(s) (ms) time Wait Class
DB CPU 120 32.5
direct path read 110,371 40 0 11.0 User I/O
db file sequential read 10,026 20 2 5.5 User I/O
control file sequential read 27,409 11 0 3.1 System I/OWhy i've too high control file sequential read?
I've read note 941761.1 and i've traced a session that create snapshot to see if there is
a table that generate to many wait.
This is the end of the trace:
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 420 0.07 0.34 0 0 8 0
Execute 852 1.19 5.70 128 2446 4602 5870
Fetch 1537 0.28 1.18 31 6939 4 1378
total 2809 1.54 7.23 159 9385 4614 7248
Misses in library cache during parse: 215
Misses in library cache during execute: 209
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
Disk file operations I/O 25 0.00 0.00
db file sequential read 178 0.32 2.00
control file sequential read 169 0.02 0.13
asynch descriptor resize 73 0.00 0.00
CSS initialization 2 0.01 0.01
CSS operation: action 2 0.01 0.02
CSS operation: query 6 0.00 0.00
kfk: async disk IO 5 0.00 0.00
direct path write 5 0.00 0.00Any ideas?Just to expand on the previous answer - your database isn't doing anything.
This is an AWR report for a 40 minute period.
You've accumulated a few seconds worth of work.
Nothing happening.
There will always be a top 5. -
Object name, segment advisor and db sequential read
oracle 10.2.0.4:
I am looking at our ADDM and AWR report. It's complaining about db file sequential read waits and also "Segment Advisor" on LOB SYS_LOB.... I have couple of questions:
1. When select is fired (from JDBC/hibernate) with the column that is of type BLOB does the blob gets extracted at that point or just the reference is returned to the BLOB. And only when that column is accessed then the blob is fetched. Or does it get fetched right away in the "Select statemement"?
2. I see Sedgment Advisor on object name LOB SYS_LOB000000012511C000006$$. How do I know which column/table it's referring to.
3. db file sequential read waits means that something is wrong with disk layout?
4. Even though our IO is not that high ADDM keeps complaining about increasing SGA to 64G. Currently as it is 32G and it's huge. Could it be because of above reasons that it thinks that it needs larger SGA?We are expecting a very high load in coming days. So I was looking at the system to check if somethings needs to be improved beforehand. I see things like 'User I/O waiting on Hot Objects", "db file sequential read waits". I read about it but I am not sure how to really see if it's going to be a problem or if it's a problem. We have indexes but one of the queries selects blob and is not always used so I was wondering if db file sequential read is being caused by that. I am not sure why we would have waiting on Hot objects because currently our system in not very busy. Hot object is a LOB and it's partitioned. It says database object with id XXXX, 0 full object scansm 25336 physical and direct reds. I know the table by looking up in DBA_LOBS.
-
Please solve the code inpsector error: Sequential read access possible
Hi,
i am getting code inspector warning message . could u please try to provide the solution for that warning message.
code inspector warning message is : Sequential read access possible for a hashed table
My statment : read table <lt_product_mbr> with table key (ujr0_c_member_id) = <l_product> assigning <ls_product_mbr>.
i declared <LT_PRODUCT_MBR> TYPE ANY TABLE.
Eventough i delared it as a type hashed or sorted . it is giving same warning message.
Regards
KotiHi Koti,
you specified the key field dynamically (variable in brackets). That means
it can not be checked statically whether the table key of the hashed table
is used or not since this is only clear at run time.
If you use the dynamic key specification
read table <lt_product_mbr> with table key (ujr0_c_member_id) = <l_product> assigning <ls_product_mbr>.
and not the direct key:
read table <lt_product_mbr> with table key field = <l_product> assigning <ls_product_mbr>.
the CI will warn you that you may end up with a sequential red (if not the table key of the hashed table
is used in the variable at run time.
Kind regards,
Hermann -
Log file sequential read and RFS ping/write - among Top 5 event
I have situation here to discuss. In a 3-node RAC setup which is Logical standby DB; one node is showing high CPU utilization around 40~50%. The CPU utilization was less than 20% 10 days back but from 9th oldest day it jumped and consistently shows the double figure. I ran AWR reports on all three nodes and found one node with high CPU utilization and shows below tops events-
EVENT WAITS TIME(S) AVG WAIT(MS) %TOTAL CALL TIME WAIT CLASS
CPU time 5,802 34.9
RFS ping 15 5,118 33,671 30.8 Other
Log file sequential read 234,831 5,036 21 30.3 System I/O
Sql*Net more data from
client 24,171 1,087 45 6.5 Network
Db file sequential read 130,939 453 3 2.7 User I/O
Findings:-
On AWR report(file attached) for node= sipd207; we can see that "RFS PING" wait event takes 30% of the waits and "log file sequential read" wait event takes 30% of the waits that occurs in database.
Environment :- (Oracle- 10.2.0.4.0, O/S - AIX .3)
1)other node awr shows "log file sync" - is it due to oversized log buffer?
2)Network wait events can be reduced by tweaking SDU & TDU values based on MDU.
3) Why ARCH processes taking much to archives filled redo logs; is it issue with slow disk I/O?
Regards
WORKLOAD REPOSITORY report for<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<DB Name DB Id Instance Inst Num Release RAC Host
XXXPDB 4123595889 XXX2p2 2 10.2.0.4.0 YES sipd207
Snap Id Snap Time Sessions Curs/Sess
Begin Snap: 1053 04-Apr-11 18:00:02 59 7.4
End Snap: 1055 04-Apr-11 20:00:35 56 7.5
Elapsed: 120.55 (mins)
DB Time: 233.08 (mins)
Cache Sizes
~~~~~~~~~~~ Begin End
Buffer Cache: 3,728M 3,728M Std Block Size: 8K
Shared Pool Size: 4,080M 4,080M Log Buffer: 14,332K
Load Profile
~~~~~~~~~~~~ Per Second Per Transaction
Redo size: 245,392.33 10,042.66
Logical reads: 9,080.80 371.63
Block changes: 1,518.12 62.13
Physical reads: 7.50 0.31
Physical writes: 44.00 1.80
User calls: 36.44 1.49
Parses: 25.84 1.06
Hard parses: 0.59 0.02
Sorts: 12.06 0.49
Logons: 0.05 0.00
Executes: 295.91 12.11
Transactions: 24.43
% Blocks changed per Read: 16.72 Recursive Call %: 94.18
Rollback per transaction %: 4.15 Rows per Sort: 53.31
Instance Efficiency Percentages (Target 100%)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Buffer Nowait %: 99.99 Redo NoWait %: 100.00
Buffer Hit %: 99.92 In-memory Sort %: 100.00
Library Hit %: 99.83 Soft Parse %: 97.71
Execute to Parse %: 91.27 Latch Hit %: 99.79
Parse CPU to Parse Elapsd %: 15.69 % Non-Parse CPU: 99.95
Shared Pool Statistics Begin End
Memory Usage %: 83.60 84.67
% SQL with executions>1: 97.49 97.19
% Memory for SQL w/exec>1: 97.10 96.67
Top 5 Timed Events Avg %Total
~~~~~~~~~~~~~~~~~~ wait Call
Event Waits Time (s) (ms) Time Wait Class
CPU time 4,503 32.2
RFS ping 168 4,275 25449 30.6 Other
log file sequential read 183,537 4,173 23 29.8 System I/O
SQL*Net more data from client 21,371 1,009 47 7.2 Network
RFS write 25,438 343 13 2.5 System I/O
RAC Statistics DB/Inst: UDAS2PDB/udas2p2 Snaps: 1053-1055
Begin End
Number of Instances: 3 3
Global Cache Load Profile
~~~~~~~~~~~~~~~~~~~~~~~~~ Per Second Per Transaction
Global Cache blocks received: 0.78 0.03
Global Cache blocks served: 1.18 0.05
GCS/GES messages received: 131.69 5.39
GCS/GES messages sent: 139.26 5.70
DBWR Fusion writes: 0.06 0.00
Estd Interconnect traffic (KB) 68.60
Global Cache Efficiency Percentages (Target local+remote 100%)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Buffer access - local cache %: 99.91
Buffer access - remote cache %: 0.01
Buffer access - disk %: 0.08
Global Cache and Enqueue Services - Workload Characteristics
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Avg global enqueue get time (ms): 0.5
Avg global cache cr block receive time (ms): 0.9
Avg global cache current block receive time (ms): 1.0
Avg global cache cr block build time (ms): 0.0
Avg global cache cr block send time (ms): 0.1
Global cache log flushes for cr blocks served %: 2.9
Avg global cache cr block flush time (ms): 4.6
Avg global cache current block pin time (ms): 0.0
Avg global cache current block send time (ms): 0.1
Global cache log flushes for current blocks served %: 0.1
Avg global cache current block flush time (ms): 5.0
Global Cache and Enqueue Services - Messaging Statistics
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Avg message sent queue time (ms): 0.1
Avg message sent queue time on ksxp (ms): 0.6
Avg message received queue time (ms): 0.0
Avg GCS message process time (ms): 0.0
Avg GES message process time (ms): 0.1
% of direct sent messages: 31.57
% of indirect sent messages: 5.17
% of flow controlled messages: 63.26
Time Model Statistics DB/Inst: UDAS2PDB/udas2p2 Snaps: 1053-1055
-> Total time in database user-calls (DB Time): 13984.6s
-> Statistics including the word "background" measure background process
time, and so do not contribute to the DB time statistic
-> Ordered by % or DB time desc, Statistic name
Statistic Name Time (s) % of DB Time
sql execute elapsed time 7,270.6 52.0
DB CPU 4,503.1 32.2
parse time elapsed 506.7 3.6
hard parse elapsed time 497.8 3.6
sequence load elapsed time 152.4 1.1
failed parse elapsed time 19.5 .1
repeated bind elapsed time 3.4 .0
PL/SQL execution elapsed time 0.7 .0
hard parse (sharing criteria) elapsed time 0.3 .0
connection management call elapsed time 0.3 .0
hard parse (bind mismatch) elapsed time 0.0 .0
DB time 13,984.6 N/A
background elapsed time 869.1 N/A
background cpu time 276.6 N/A
Wait Class DB/Inst: UDAS2PDB/udas2p2 Snaps: 1053-1055
-> s - second
-> cs - centisecond - 100th of a second
-> ms - millisecond - 1000th of a second
-> us - microsecond - 1000000th of a second
-> ordered by wait time desc, waits desc
Avg
%Time Total Wait wait Waits
Wait Class Waits -outs Time (s) (ms) /txn
System I/O 529,934 .0 4,980 9 3.0
Other 582,349 37.4 4,611 8 3.3
Network 279,858 .0 1,009 4 1.6
User I/O 54,899 .0 317 6 0.3
Concurrency 136,907 .1 58 0 0.8
Cluster 60,300 .0 41 1 0.3
Commit 80 .0 10 130 0.0
Application 6,707 .0 3 0 0.0
Configuration 17,528 98.5 1 0 0.1
Wait Events DB/Inst: UDAS2PDB/udas2p2 Snaps: 1053-1055
-> s - second
-> cs - centisecond - 100th of a second
-> ms - millisecond - 1000th of a second
-> us - microsecond - 1000000th of a second
-> ordered by wait time desc, waits desc (idle events last)
Avg
%Time Total Wait wait Waits
Event Waits -outs Time (s) (ms) /txn
RFS ping 168 .0 4,275 25449 0.0
log file sequential read 183,537 .0 4,173 23 1.0
SQL*Net more data from clien 21,371 .0 1,009 47 0.1
RFS write 25,438 .0 343 13 0.1
db file sequential read 54,680 .0 316 6 0.3
DFS lock handle 97,149 .0 214 2 0.5
log file parallel write 104,808 .0 157 2 0.6
db file parallel write 143,905 .0 149 1 0.8
RFS random i/o 25,438 .0 86 3 0.1
RFS dispatch 25,610 .0 56 2 0.1
control file sequential read 39,309 .0 55 1 0.2
row cache lock 130,665 .0 47 0 0.7
gc current grant 2-way 35,498 .0 23 1 0.2
wait for scn ack 50,872 .0 20 0 0.3
enq: WL - contention 6,156 .0 14 2 0.0
gc cr grant 2-way 16,917 .0 11 1 0.1
log file sync 80 .0 10 130 0.0
Log archive I/O 3,986 .0 9 2 0.0
control file parallel write 3,493 .0 8 2 0.0
latch free 2,356 .0 6 2 0.0
ksxr poll remote instances 278,473 49.4 6 0 1.6
enq: XR - database force log 2,890 .0 4 1 0.0
enq: TX - index contention 325 .0 3 11 0.0
buffer busy waits 4,371 .0 3 1 0.0
gc current block 2-way 3,002 .0 3 1 0.0
LGWR wait for redo copy 9,601 .2 2 0 0.1
SQL*Net break/reset to clien 6,438 .0 2 0 0.0
latch: ges resource hash lis 23,223 .0 2 0 0.1
enq: WF - contention 32 6.3 2 62 0.0
enq: FB - contention 660 .0 2 2 0.0
enq: PS - contention 1,088 .0 2 1 0.0
library cache lock 869 .0 1 2 0.0
enq: CF - contention 671 .1 1 2 0.0
gc current grant busy 1,488 .0 1 1 0.0
gc current multi block reque 1,072 .0 1 1 0.0
reliable message 618 .0 1 2 0.0
CGS wait for IPC msg 62,402 100.0 1 0 0.4
gc current block 3-way 998 .0 1 1 0.0
name-service call wait 18 .0 1 57 0.0
cursor: pin S wait on X 78 100.0 1 11 0.0
os thread startup 16 .0 1 53 0.0
enq: RO - fast object reuse 193 .0 1 3 0.0
IPC send completion sync 652 99.2 1 1 0.0
local write wait 194 .0 1 3 0.0
gc cr block 2-way 534 .0 0 1 0.0
log file switch completion 17 .0 0 20 0.0
SQL*Net message to client 258,483 .0 0 0 1.5
undo segment extension 17,282 99.9 0 0 0.1
gc cr block 3-way 286 .7 0 1 0.0
enq: TM - contention 76 .0 0 4 0.0
PX Deq: reap credit 15,246 95.6 0 0 0.1
kksfbc child completion 5 100.0 0 49 0.0
enq: TT - contention 141 .0 0 2 0.0
enq: HW - contention 203 .0 0 1 0.0
RFS create 2 .0 0 115 0.0
rdbms ipc reply 339 .0 0 1 0.0
PX Deq Credit: send blkd 452 20.1 0 0 0.0
gcs log flush sync 128 32.8 0 2 0.0
latch: cache buffers chains 128 .0 0 1 0.0
library cache pin 441 .0 0 0 0.0
Wait Events DB/Inst: UDAS2PDB/udas2p2 Snaps: 1053-1055
-> s - second
-> cs - centisecond - 100th of a second
-> ms - millisecond - 1000th of a second
-> us - microsecond - 1000000th of a second
-> ordered by wait time desc, waits desc (idle events last)We only apply on one node in a cluster so I would expect that the node running SQL Apply would have much higher usage and waits. Is this what you are asking?
Larry -
Select using Indexed field, still using sequential read
Hi Experts,
I am selecting from CATSDB table
SELECT SINGLE * FROM catsdb
WHERE belnr = var.
BELNR is indexed so I am expecting that this statement will do a direct read.
But when this statement is run, SAP message indicates that
it is performing a sequential read. Anybody knows why this is? And how do I make direct read happen?
Thank you very much for your help.
Bes Regards,
RoseHi,
may be you need to update the database statistics for that table or you need to recreate the index. Check out db02 for the table or make some check using se14.
regards
Siggi
PS: Also fm rsdu_analyze_tables will be of some help. do a test run in se37 and enter the name of the table.
Message was edited by:
Siegfried Szameitat -
Query occasionally causes table scans (db file sequential read)
Dear all,
we periodically issue a query on a huge table via an oracle job.
Whenever I invoke the query manually, the response time is good. When I start the periodic job, initially the response times are good as well. After some days, however, the query suddenly takes almost forever.
My vague guess is that for some reason the query suddenly changes the execution plan from using the primary key index to a full table scan (or huge index range scan). Maybe because of some problems with the primary key index (fragmentation? Other?).
- Could it be the case that the execution plan for a query changes (automatically) like this? For what reasons?
- Do you have any hints where to look for further information for analysis? (logs, special event types, ...)?
- Of course, the query was designed having involved indexes in mind. Also, I studied the execution plan and did not find hints for problematic table/range scans.
- It is not a lock contention problem
- When the query "takes forever", there is a "db file sequential read" event in v$session_event for the query with an ever increasing wait time. That's why I guess a (unreasonable) table scan is happening.
Some charachteristics of the table in question:
- ~ 30 Mio rows
- There are only insertions to the table, as well as updates on a single, indexed field. No deletes.
- There is an integer primary key field with an B-tree index.
Charachteristics of the query:
The main structure of the query is very simple and as follows: I select a range of about 100 rows via primary key "id", like:
Select * from TheTable where id>11222300 and id <= 11222400
There are several joins with rather small tables, which make the overall query more complicated.
However, the few (100) rows of the huge table in question should always be fetched using the primary key index, shouldn't it?
Please let me know if some relevant information about the problem is missing.
Thanks!
Best regards,
Nang.user2560749 wrote:
Dear all,
we periodically issue a query on a huge table via an oracle job.
Whenever I invoke the query manually, the response time is good. When I start the periodic job, initially the response times are good as well. After some days, however, the query suddenly takes almost forever.
My vague guess is that for some reason the query suddenly changes the execution plan from using the primary key index to a full table scan (or huge index range scan). Maybe because of some problems with the primary key index (fragmentation? Other?).
- Could it be the case that the execution plan for a query changes (automatically) like this? For what reasons?Yes possible, One reason is stats of the table has been changed i.e somebody issued dbms_stats. If you are worried about execution plan getting changed then two option 1) Lock the stats 2) Use hint in the query.
- Do you have any hints where to look for further information for analysis? (logs, special event types, ...)?Have a Ora-10053 trace enabled whenever query plan changes and analysis it.
- Of course, the query was designed having involved indexes in mind. Also, I studied the execution plan and did not find hints for problematic table/range scans.
- It is not a lock contention problem
- When the query "takes forever", there is a "db file sequential read" event in v$session_event for the query with an ever increasing wait time. That's why I guess a (unreasonable) table scan is happening.
If it db file sequential read then i see two things 1) It is doing index range scan(Not table full scan) or 2) It is scanning undo tablespaces.
Some charachteristics of the table in question:
- ~ 30 Mio rows
- There are only insertions to the table, as well as updates on a single, indexed field. No deletes.
- There is an integer primary key field with an B-tree index.
Charachteristics of the query:
The main structure of the query is very simple and as follows: I select a range of about 100 rows via primary key "id", like:
Select * from TheTable where id>11222300 and id <= 11222400
There are several joins with rather small tables, which make the overall query more complicated.
However, the few (100) rows of the huge table in question should always be fetched using the primary key index, shouldn't it?
Yes theoreitically it should practically we can only say by looking at run time explain plan(through 10053,10046 trace).
Please let me know if some relevant information about the problem is missing.
Thanks!
Best regards,
Nang.I am still not sure in which direction you are looking for solution.
Is your query performing bad once in a fortnight and next day it is all same again.
I suggest to
1) Check if the data is scanning undo tablespace. I see you mentioned there is lot of inserts, could be that Oracle would be scanning undo tablespace because of delayed clean out.
2) Check if that particular day the number of records are high compared to other day.
Or once it starts performing bad then for next couple of days there is no change in response time.
1) Check if explain plan has been changed?
And what action you take to bring back the response time to normal?
Regards
Anurag -
Dear friends,
In one of our client oracle is used as SAP DB.
Here the major problem is, even though the reports made use of primary and secondary indexs, they are going to sequential read instead of direct read and the performance is badly affected.
Kindly suggest.
Praveen LoboHere the major problem is, even though the reports made use of primary and secondary indexs, they are going to sequential read instead of direct read and the performance is badly affected.
First: don´t rely on information on SM50/SM66.
Second: did you do an SQL trace in ST05 for the statement and see what execution plan is used?
Markus -
Long time to load data from PSA to DSO / CUBE. Sequential read RSBKDATA_V
Hi Gurus
The process stays for several hours on sequential read from RSBKDATA_V - temporary storage for DTPs.
After several hours, the processing finally starts, but even when I assign several BGDs to the DTP it takes hours to load the data.
We have BI7.0 with SP22, so all relevant notes are already implemented.
Does any one had similar problem, please?
Thanks in advance
MartinHi Martin,
this issue has cropped up a few times. Please check and implement the following notes:
1338465 P22:DTP:LOG: Performance problem when messages are added +
1331544 P22:HINT:Slow performance when accessing RSMONFACT +
1312701 70SP21: Performance on view RSBKDATA_V selects
1304234 70SP21: Performance on the hashed table p_th_rsbkdata_v **
1168098 70SP19: Performance during DataStore object extraction
1080027 70SP16: Performance during parallel processing
These notes should improve the performance of the DTPs in your system.
After you've added the notes, please check in tables RSBKDATA and RSBKDATAINFO whether they contain any data. If the tables are empty, please reorganise the tables, and restart the dtp.
Hope this helps you.
Rgds,
Colum -
Performance problems due to sequential read on tables WBCROSSGT and CROSS
Hello all,
got the SAPNW2004s Sneak Preview ABAP installed. Performance is quite ok. But with certain dictionary operations like creating new attributes for a class I experience exceptional long runtimes and timeout dumps. In SM50 I see a sequential read on table WBCROSSGT. In OSS I can't find anything applicable yet for this release (SAP_BASIS 700, support level 5).
Any suggestions appreciated.
SimonHello,
i had exactly the same problem after upgrading from MS SQL 2005 to MS SQl 2008 R2.
Our DEV system was almost completely exhausted and normal operation wasn't possible anymore.
SAP Note 1479008 solved the issue, even it is only "released" for MaxDB.
Cheers, Christoph -
Long time to load data from PSA to DSO -Sequential read RSBKDATA_V
Hi ,
It is taking long time to load data from PSA to DSO. It is doing Sequential read on RSBKDATA_V and table contents no data .
we are at - SAPKW70105. It started since yesterday . There is no changes in system parameters.
Please advice.
Thanks
NileshHi Nilesh,
I guess the following SAP Note will help you in this situation.
[1476842 - Performance: read RSBKDATA only when needed|https://websmp107.sap-ag.de/sap/support/notes/1476842]
Just note that the reference to Support Packages is wrong. It is also included in SAP_BW 701 06.
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