"the db file sequential read" waiting for event slow down an application.

"the db file sequential read" waiting for event slow down an application.

It is a rather strange problem. There is an update statement that hangs on the wait event 'db file sequential read' and until you restart the database, the query works fine. It happens once a week, usually Monday or after several days of large amount of work.

I checked the processor and is fine, memory is very good, although the SGA and PGA have taken maximum memory. Flow of the disc seems to be ok since each another session on the basis of data looks very good.

I guess that there is a missing configuration to avoid having to restart the database each week.

Any help is greatly appreciated.

Hello

If you want same order of the tables as plain exp after reboot just go with ordered hint

UPDATE item_work_step
SET user_name = :b1,
terminal = SYS_CONTEXT ('USERENV', 'TERMINAL'),
status_cd = 'IN PROCESS'
WHERE item_work_step_route_id =
(SELECT item_work_step_route_id
FROM (SELECT /*+ORDERED */ iws.item_work_step_route_id
FROM user_role ur,
work_step_role wsr,
work_step ws,
app_step aps,
item_work_step iws,
item_work iw,
item i
WHERE wsr.role_cd = ur.role_cd
AND ws.work_step_id = wsr.work_step_id
AND aps.step_cd = ws.step_cd
AND iws.work_step_id = ws.work_step_id
AND iws.work_id = ws.work_id
AND iws.step_cd = ws.step_cd
AND iws.status_cd = 'READY'
AND iw.item_work_id = iws.item_work_id
AND iw.item_id = iws.item_id
AND iw.work_id = iws.work_id
AND i.item_id = iws.item_id
AND i.item_id = iw.item_id
AND i.deleted = 'N'
AND i.item_type_master_cd = :b3
AND ur.user_name = :b1
AND aps.app_name = :b2
AND ( iws.assignment_user_or_role IS NULL
OR ( iws.assignment_user_or_role IN (
SELECT ur.role_cd
FROM user_role ur
WHERE ur.user_name = :b1
UNION ALL
SELECT :b1
FROM dual)
AND iws.assignment_expiration_time > SYSDATE
)
OR ( iws.assignment_user_or_role IS NOT NULL
AND iws.assignment_expiration_time <= SYSDATE
)
)
AND (iws.pend_date IS NULL OR iws.pend_date <= SYSDATE
)
ORDER BY aps.priority,
LEAST (NVL (iw.priority, 9999),
NVL ((SELECT NVL (priority, 9999)
FROM item_work
WHERE item_id = i.parent_id
AND work_id = 42),
9999
)
),
DECODE (i.a3, NULL, 0, 1),
NVL (iw.sla_deadline,
(SELECT sla_deadline
FROM item_work
WHERE item_id = i.parent_id
AND work_id = 42)
),
i.parent_id,
i.item_id) unclaimed_item_work_step
WHERE ROWNUM <= 1)

If you want to get rid of the nested loops use USE_HASH

UPDATE item_work_step
SET user_name = :b1,
terminal = SYS_CONTEXT ('USERENV', 'TERMINAL'),
status_cd = 'IN PROCESS'
WHERE item_work_step_route_id =
(SELECT item_work_step_route_id
FROM (SELECT /*+ORDERED USE_HASH(ur wsr ws aps iws iw i) */ iws.item_work_step_route_id
FROM user_role ur,
work_step_role wsr,
work_step ws,
app_step aps,
item_work_step iws,
item_work iw,
item i
WHERE wsr.role_cd = ur.role_cd
AND ws.work_step_id = wsr.work_step_id
AND aps.step_cd = ws.step_cd
AND iws.work_step_id = ws.work_step_id
AND iws.work_id = ws.work_id
AND iws.step_cd = ws.step_cd
AND iws.status_cd = 'READY'
AND iw.item_work_id = iws.item_work_id
AND iw.item_id = iws.item_id
AND iw.work_id = iws.work_id
AND i.item_id = iws.item_id
AND i.item_id = iw.item_id
AND i.deleted = 'N'
AND i.item_type_master_cd = :b3
AND ur.user_name = :b1
AND aps.app_name = :b2
AND ( iws.assignment_user_or_role IS NULL
OR ( iws.assignment_user_or_role IN (
SELECT ur.role_cd
FROM user_role ur
WHERE ur.user_name = :b1
UNION ALL
SELECT :b1
FROM dual)
AND iws.assignment_expiration_time > SYSDATE
)
OR ( iws.assignment_user_or_role IS NOT NULL
AND iws.assignment_expiration_time <= SYSDATE
)
)
AND (iws.pend_date IS NULL OR iws.pend_date <= SYSDATE
)
ORDER BY aps.priority,
LEAST (NVL (iw.priority, 9999),
NVL ((SELECT NVL (priority, 9999)
FROM item_work
WHERE item_id = i.parent_id
AND work_id = 42),
9999
)
),
DECODE (i.a3, NULL, 0, 1),
NVL (iw.sla_deadline,
(SELECT sla_deadline
FROM item_work
WHERE item_id = i.parent_id
AND work_id = 42)
),
i.parent_id,
i.item_id) unclaimed_item_work_step
WHERE ROWNUM <= 1)

and for small tables, you can try adding for example FULL (your) FULL (wsr)

It can be rewritten in a different way, but it's the fastest way to try how query will be if you rewrite it. Check the explain plan command if certain partially ordered tables are not joined because you can get the Cartesian join, it seems that it will be ok.

View query result in the em console.

Concerning

Tags: Database

Similar Questions

Reason for 'control file sequential read' wait?
Hello

We have a 10.2.0.4.0 2. node RAC database on Windows 2003 (all 64-bit).

By looking at the 'top 5 timed events' section AWR reports (for 1 hour), we still see the 'time of CPU", as the number one event (due to our application, certain questions if all goes well in the study now by developers...), but recently I see"sequential read from the command file"as the event number two, with 3 574 633 expects and 831 time s. I was hoping to find out what was causing this high number of expectations. I started by trying to find a particular query that has experienced this expectation often, so I ran this SQL:
```
select sql_id, count(*)
from dba_hist_active_sess_history
where event_id = (select event_id from v$event_name where name = 'control file sequential read')
group by sql_id
order by 2 desc ;
```
As I hoped, the sql_id top of page returned really stands out, with an equal number of 14 182 (the next sql_id has a counter of 68). This is the text of the sql for this id:
```
WITH unit AS( 
          SELECT UNIQUE S.unit_id
          FROM STOCK S, HOLDER H
          WHERE  H.H_ID = S.H_ID 
            AND  H.LOC_ID  = :B2 
            AND  S.PROD_ID   = :B1 
            ) 
SELECT  DECODE((SELECT COUNT(*) FROM unit), 1, unit_ID, NULL) 
 FROM   unit
WHERE   ROWNUM = 1
;
```
(Ok, code a little strange, but I already have them change it.)

My question is:

Why / what is this code should read in the control file?

Kind regards

ADOS

PS - I also checked the block number in dba_hist_active_sess_history for this sql_id and event_id p2, and it is still one of the 5 blocks in the controlfile. I've spilled the controlfile, but do not see anything interesting (even if it is true, it is the first time I've thrown a controlfile so have no idea really what to do!).
Hello
ADO wrote:
```
WITH unit AS(
          SELECT UNIQUE S.unit_id
          FROM STOCK S, HOLDER H
          WHERE  H.H_ID = S.H_ID
            AND  H.LOC_ID  = :B2
            AND  S.PROD_ID   = :B1
)
SELECT  DECODE((SELECT COUNT(*) FROM unit), 1, unit_ID, NULL)
FROM   unit
WHERE   ROWNUM = 1
;
```
This query contains a subquery factoring clause; and as it refers to the unit twice in the main part, chances are subquery factoring is to be materialized in a global temporary table in the schema SYS with SYS_TEMP_ Name% and is accessible on two occasions in the execution plan later (check presence stage of TRANSFORMATION TABLE TEMP). The step of filling of this intermediate table requires you to write in the temporary tablespace - and it's done via direct writing. Each direct entry to the segment (i.e. directly in the file on the disk) requires a data file status check - what is online or offline - that is done by access control files. So you see these expectations. This is one of the many things why subquery factoring is not good for production OLTP environments.

DB file sequential read and read of the direct path

Hello

Could someone please clear my doubts about 'db file sequential read' and ' path direct reading. And help me understand the tkprof report correctly.
Please suggest if my understanding for scenario below is correct.

We have a 11.2.0.1 ' cluster 2 node rac version + asm' production and environment of his test environment that is a stand-alone database.
The query performs well in production compared to the test database.
The table is to have 254 + columns (264) with many lobs coulumns however LOB is not currently selected in the query.
I read in metalink this 254 table + column a intra-line-chaining, causing "db file sequential read" full table Scan.

Here are some details on the table which is similar to the prod and test, block size is 8 k:

TABLE                             UNUSED BLOCKS     TOTAL BLOCKS  HIGH WATER MARK
------------------------------  ---------------  ---------------  ---------------
PROBSUMMARYM1                               0          17408          17407

What I understand less tkprof in production environment for a given session is:
1 - the request resulted in disk 19378 readings and 145164 consistent readings.
2 19378 disc bed, 2425 reads disc has given rise to the wait event 'db file sequential read'.
This statement is correct this disc remaining readings were "db file sequential reads" but real quick so didn't wait event tied to it?
3 - 183 'direct path read' there also. Is it because of the order by clause of the query?

SQL ID: 72tvt5h4402c9
Plan Hash: 1127048874
select "NUMBER" num 
from
 smprd.probsummarym1 where flag ='f' and affected_item = 'PAUSRWVP39486' 
  order by num asc


call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse        1      0.00       0.00          0          0          0           0
Execute      1      0.00       0.00          0          0          0           0
Fetch        1      0.53       4.88      19378     145164          0           0
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total        3      0.53       4.88      19378     145164          0           0

Misses in library cache during parse: 0
Optimizer mode: ALL_ROWS
Parsing user id: SYS

Rows     Row Source Operation
-------  ---------------------------------------------------
      0  SORT ORDER BY (cr=145164 pr=19378 pw=0 time=0 us cost=4411 size=24 card=2)
      0   TABLE ACCESS FULL PROBSUMMARYM1 (cr=145164 pr=19378 pw=0 time=0 us cost=4410 size=24 card=2)


Elapsed times include waiting on following events:
  Event waited on                             Times   Max. Wait  Total Waited
  ----------------------------------------   Waited  ----------  ------------
  SQL*Net message to client                       1        0.00          0.00
  ges message buffer allocation                   3        0.00          0.00
  enq: KO - fast object checkpoint                2        0.00          0.00
  reliable message                                1        0.00          0.00
  KJC: Wait for msg sends to complete             1        0.00          0.00
  Disk file operations I/O                        1        0.00          0.00
  kfk: async disk IO                            274        0.00          0.00
  direct path read                              183        0.01          0.72
  db file sequential read                      2425        0.05          3.71
  SQL*Net message from client                     1        2.45          2.45

The same query when ran in no no rac - asm test stand alone database has given below tkprof.
Does this mean that:
1-here too, reads happen through "db file sequential read", but they were so fast that has failed to the wait event?
2. "direct path read," it's because of the order clause in the query. "

SQL ID: 72tvt5h4402c9
Plan Hash: 1127048874
select "NUMBER" num 
from
 smprd.probsummarym1 where flag ='f' and affected_item = 'PAUSRWVP39486' 
  order by num asc


call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse        1      0.00       0.00          0          0          0           0
Execute      1      0.00       0.06          0          0          0           0
Fetch        1      0.10       0.11      17154      17298          0           0
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total        3      0.10       0.18      17154      17298          0           0

Misses in library cache during parse: 0
Optimizer mode: ALL_ROWS
Parsing user id: SYS

Rows     Row Source Operation
-------  ---------------------------------------------------
      0  SORT ORDER BY (cr=17298 pr=17154 pw=0 time=0 us cost=4694 size=12 card=1)
      0   TABLE ACCESS FULL PROBSUMMARYM1 (cr=17298 pr=17154 pw=0 time=0 us cost=4693 size=12 card=1)


Elapsed times include waiting on following events:
  Event waited on                             Times   Max. Wait  Total Waited
  ----------------------------------------   Waited  ----------  ------------
  SQL*Net message to client                       1        0.00          0.00
  Disk file operations I/O                        1        0.00          0.00
  db file sequential read                         3        0.00          0.00
  direct path read                              149        0.00          0.03
  SQL*Net message from client                     1        2.29          2.29

For trace files in the database Production and Test, I see that 'direct path read' is against the same data file that's stored table.
Then how come 'this direct path read' because of the order by clause of the query and would have been in sort field size or pga?
Or this direct path read extracts real PGA disk data, and "db file sequential read" do not extract data?
I know, it's 'direct path read' is wait event when data are asked in PGA drive or what kind segment or temp tablespace is used.

Here is the example of trace file in the Production database:

*** 2013-01-04 13:49:15.109
WAIT #1: nam='SQL*Net message from client' ela= 11258483 driver id=1650815232 #bytes=1 p3=0 obj#=-1 tim=1357278555109496
CLOSE #1:c=0,e=9,dep=0,type=1,tim=1357278555109622
=====================
PARSING IN CURSOR #1 len=113 dep=0 uid=0 oct=3 lid=0 tim=1357278555109766 hv=138414473 ad='cfc02ab8' sqlid='72tvt5h4402c9'
select "NUMBER" num from smprd.probsummarym1 where flag ='f' and affected_item = 'PAUSRWVP39486' order by num asc
END OF STMT
PARSE #1:c=0,e=98,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,plh=1127048874,tim=1357278555109765
EXEC #1:c=0,e=135,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,plh=1127048874,tim=1357278555109994
WAIT #1: nam='SQL*Net message to client' ela= 2 driver id=1650815232 #bytes=1 p3=0 obj#=-1 tim=1357278555110053
WAIT #1: nam='ges message buffer allocation' ela= 3 pool=0 request=1 allocated=0 obj#=-1 tim=1357278555111630
WAIT #1: nam='enq: KO - fast object checkpoint' ela= 370 name|mode=1263468550 2=65610 0=1 obj#=-1 tim=1357278555112098
WAIT #1: nam='reliable message' ela= 1509 channel context=3691837552 channel handle=3724365720 broadcast message=3692890960 obj#=-1 tim=1357278555113975
WAIT #1: nam='ges message buffer allocation' ela= 2 pool=0 request=1 allocated=0 obj#=-1 tim=1357278555114051
WAIT #1: nam='enq: KO - fast object checkpoint' ela= 364 name|mode=1263468550 2=65610 0=1 obj#=-1 tim=1357278555114464
WAIT #1: nam='KJC: Wait for msg sends to complete' ela= 9 msg=3686348728 dest|rcvr=65536 mtype=8 obj#=-1 tim=1357278555114516
WAIT #1: nam='ges message buffer allocation' ela= 2 pool=0 request=1 allocated=0 obj#=-1 tim=1357278555114680
WAIT #1: nam='Disk file operations I/O' ela= 562 FileOperation=2 fileno=6 filetype=2 obj#=85520 tim=1357278555115710
WAIT #1: nam='kfk: async disk IO' ela= 5 count=1 intr=0 timeout=4294967295 obj#=85520 tim=1357278555117332

*** 2013-01-04 13:49:15.123
WAIT #1: nam='direct path read' ela= 6243 file number=6 first dba=11051 block cnt=5 obj#=85520 tim=1357278555123628
WAIT #1: nam='db file sequential read' ela= 195 file#=6 block#=156863 blocks=1 obj#=85520 tim=1357278555123968
WAIT #1: nam='db file sequential read' ela= 149 file#=6 block#=156804 blocks=1 obj#=85520 tim=1357278555124216
WAIT #1: nam='db file sequential read' ela= 155 file#=6 block#=156816 blocks=1 obj#=85520 tim=1357278555124430
WAIT #1: nam='db file sequential read' ela= 4826 file#=6 block#=156816 blocks=1 obj#=85520 tim=1357278555129317
WAIT #1: nam='db file sequential read' ela= 987 file#=6 block#=156888 blocks=1 obj#=85520 tim=1357278555130427
WAIT #1: nam='db file sequential read' ela= 3891 file#=6 block#=156888 blocks=1 obj#=85520 tim=1357278555134394
WAIT #1: nam='db file sequential read' ela= 155 file#=6 block#=156912 blocks=1 obj#=85520 tim=1357278555134645
WAIT #1: nam='db file sequential read' ela= 145 file#=6 block#=156920 blocks=1 obj#=85520 tim=1357278555134866
WAIT #1: nam='db file sequential read' ela= 234 file#=6 block#=156898 blocks=1 obj#=85520 tim=1357278555135332
WAIT #1: nam='db file sequential read' ela= 204 file#=6 block#=156907 blocks=1 obj#=85520 tim=1357278555135666
WAIT #1: nam='kfk: async disk IO' ela= 4 count=1 intr=0 timeout=4294967295 obj#=85520 tim=1357278555135850
WAIT #1: nam='direct path read' ela= 6894 file number=6 first dba=72073 block cnt=15 obj#=85520 tim=1357278555142774
WAIT #1: nam='db file sequential read' ela= 4642 file#=6 block#=156840 blocks=1 obj#=85520 tim=1357278555147574
WAIT #1: nam='db file sequential read' ela= 162 file#=6 block#=156853 blocks=1 obj#=85520 tim=1357278555147859
WAIT #1: nam='db file sequential read' ela= 6469 file#=6 block#=156806 blocks=1 obj#=85520 tim=1357278555154407
WAIT #1: nam='db file sequential read' ela= 182 file#=6 block#=156826 blocks=1 obj#=85520 tim=1357278555154660
WAIT #1: nam='db file sequential read' ela= 147 file#=6 block#=156830 blocks=1 obj#=85520 tim=1357278555154873
WAIT #1: nam='db file sequential read' ela= 145 file#=6 block#=156878 blocks=1 obj#=85520 tim=135727855515

Here are the trace file for the test database:

*** 2013-01-04 13:46:11.354
WAIT #1: nam='SQL*Net message from client' ela= 10384792 driver id=1650815232 #bytes=1 p3=0 obj#=-1 tim=1357278371354075
CLOSE #1:c=0,e=3,dep=0,type=3,tim=1357278371354152
=====================
PARSING IN CURSOR #1 len=113 dep=0 uid=0 oct=3 lid=0 tim=1357278371363427 hv=138414473 ad='c7bd8d00' sqlid='72tvt5h4402c9'
select "NUMBER" num from smprd.probsummarym1 where flag ='f' and affected_item = 'PAUSRWVP39486' order by num asc
END OF STMT
PARSE #1:c=0,e=9251,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,plh=1127048874,tim=1357278371363426
EXEC #1:c=0,e=63178,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,plh=1127048874,tim=1357278371426691
WAIT #1: nam='SQL*Net message to client' ela= 2 driver id=1650815232 #bytes=1 p3=0 obj#=-1 tim=1357278371426766
WAIT #1: nam='Disk file operations I/O' ela= 1133 FileOperation=2 fileno=55 filetype=2 obj#=93574 tim=1357278371428069
WAIT #1: nam='db file sequential read' ela= 51 file#=55 block#=460234 blocks=1 obj#=93574 tim=1357278371428158
WAIT #1: nam='direct path read' ela= 31 file number=55 first dba=460235 block cnt=5 obj#=93574 tim=1357278371428956
WAIT #1: nam='direct path read' ela= 47 file number=55 first dba=136288 block cnt=8 obj#=93574 tim=1357278371429099
WAIT #1: nam='direct path read' ela= 80 file number=55 first dba=136297 block cnt=15 obj#=93574 tim=1357278371438529
WAIT #1: nam='direct path read' ela= 62 file number=55 first dba=136849 block cnt=15 obj#=93574 tim=1357278371438653
WAIT #1: nam='direct path read' ela= 17 file number=55 first dba=136881 block cnt=7 obj#=93574 tim=1357278371438750
WAIT #1: nam='direct path read' ela= 35 file number=55 first dba=136896 block cnt=8 obj#=93574 tim=1357278371438855
WAIT #1: nam='direct path read' ela= 22 file number=55 first dba=136913 block cnt=7 obj#=93574 tim=1357278371438936
WAIT #1: nam='direct path read' ela= 19 file number=55 first dba=137120 block cnt=8 obj#=93574 tim=1357278371439029
WAIT #1: nam='direct path read' ela= 36 file number=55 first dba=137145 block cnt=7 obj#=93574 tim=1357278371439114
WAIT #1: nam='direct path read' ela= 18 file number=55 first dba=137192 block cnt=8 obj#=93574 tim=1357278371439193
WAIT #1: nam='direct path read' ela= 16 file number=55 first dba=137201 block cnt=7 obj#=93574 tim=1357278371439252
WAIT #1: nam='direct path read' ela= 17 file number=55 first dba=137600 block cnt=8 obj#=93574 tim=1357278371439313
WAIT #1: nam='direct path read' ela= 15 file number=55 first dba=137625 block cnt=7 obj#=93574 tim=1357278371439369
WAIT #1: nam='direct path read' ela= 22 file number=55 first dba=137640 block cnt=8 obj#=93574 tim=1357278371439435
WAIT #1: nam='direct path read' ela= 702 file number=55 first dba=801026 block cnt=126 obj#=93574 tim=1357278371440188
WAIT #1: nam='direct path read' ela= 1511 file number=55 first dba=801154 block cnt=126 obj#=93574 tim=1357278371441763
WAIT #1: nam='direct path read' ela= 263 file number=55 first dba=801282 block cnt=126 obj#=93574 tim=1357278371442547
WAIT #1: nam='direct path read' ela= 259 file number=55 first dba=801410 block cnt=126 obj#=93574 tim=1357278371443315
WAIT #1: nam='direct path read' ela= 294 file number=55 first dba=801538 block cnt=126 obj#=93574 tim=1357278371444099
WAIT #1: nam='direct path read' ela= 247 file number=55 first dba=801666 block cnt=126 obj#=93574 tim=1357278371444843
WAIT #1: nam='direct path read' ela= 266 file number=55 first dba=801794 block cnt=126 obj#=93574 tim=1357278371445619

Thanks & Rgds,
Vijay

911786 wrote:

Direct path readings can be done on the series tablescans in your version of Oracle, but if you have chained rows in the table and then Oracle can read read read the beginning of the line in the path directly, but must make a single block in the cache (the db file sequential read) to get the next part of the line.

It is possible that your production system has a lot of chained rows, while your test system is not. As corroboration (though not convincing) indicator of what you might notice that if you take (reads disc - db file sequential reads) - who might get you close to all the blocks direct read - the numbers are very similar.

I'm not 100% convinced that it's the answer for the difference in behavior, but worth a visit. If you can force and indexed access path in the table, do something like "select / * + index (use {pk}) * / max table (last_column_in_table)" and check the number of "table fetch continued lines" could be close to the number of db file sequential reads you. (There are other options for the counting of the chained rows that could be faster).

Concerning
Jonathan Lewis

query on dba_free_space ends waiting for events db file sequential read

Hi all

Env: 10gr 2 on Windows NT

I gave the query
Select tablespace_name, sum (bytes) / 1024/1024 dba_free_space group by tablespace_name and her for still waiting.
I checked the event waiting for v$ session and «db file sequential read»

I put a trace on the session before launching the above query:

 



OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS



call     count       cpu    elapsed       disk      query    current        rows

-----

Parse        1      0.06       0.06          0          0          0           0

Execute      1      0.00       0.00          0          0          0           0

Fetch        0      0.00       0.00          0          0          0           0

-----

total        2      0.06       0.06          0          0          0           0



Misses in library cache during parse: 1



Elapsed times include waiting on following events:

  Event waited on                             Times   Max. Wait  Total Waited

  ----------------------------------------

  db file sequential read                     13677        0.16        151.34

  SQL*Net message to client                       1        0.00          0.00

  db file scattered read                        281        0.01          0.53

  latch: cache buffers lru chain                  2        0.00          0.00





OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS



call     count       cpu    elapsed       disk      query    current        rows

------

Parse    13703      0.31       0.32          0          0          0           0

Execute  14009      0.75       0.83          0          0          0           0

Fetch    14139      0.48       0.74         26      56091          0       15496

------

total    41851      1.54       1.89         26      56091          0       15496



Misses in library cache during parse: 16

Misses in library cache during execute: 16



Elapsed times include waiting on following events:

  Event waited on                             Times   Max. Wait  Total Waited

  ----------------------------------------

  db file sequential read                        26        0.00          0.12



    1  user  SQL statements in session.

14010  internal SQL statements in session.

14011  SQL statements in session.

I took the AWR report (for 1 hour) and the top 5 events are out like,

Event                                 Waits    Time (s)   (ms)   Time Wait Class

------

db file sequential read           1,134,643       7,580      7   56.8   User I/O

db file scattered read              940,880       5,025      5   37.7   User I/O

CPU time                                            967           7.2

control file sequential read          4,987           3      1    0.0 System I/O

control file parallel write           2,408           1      1    0.0 System I/O

The PHYRDS (from dba_hist_filestatxs) on my system01.dbf is 161,028,980 for the final nod.

Could someone shed some light on what is happening here?

TIA,
JJ

In certain circumstances, questioning the dictionary can be slow, usually due to problems with bad bad statistics-related implementation plans, trying to collect statistics using dbms_stats.gather_fixed_objects_stats (); It has worked for me before.
You can also read Note 414256.1 poor performance for Tablespace Page in Grid Control display Console that also indicates a possible problem with the trash.

HTH

Enrique

DB file sequential reads on the table scan complete and LRU (new)

I would like to add a question on the subject
scan of full table and LRU
According to MOS doc ument 1457693.1
«.. signs diluvium readings of the caching blocks can be divided into a number of small multiblock and self-contained bed. »
The question is if sequential readings of db file submitted by a FULL SCAN operation will be cached on LRU or MRU list?
I'm afraid the flushes of heat/floods the buffer cache with a lot of FULL SCAN db file sequential reads.
For which direct path series reason readings will be inapplicable, so using this new feature of 11g is out of scope for this question.
Thank you for your interest,
Rainer Stenzel

There are a few different patterns of behavior depends on the size of the table (relative to the size of the buffer cache), but the key question is probably "readings will increment the counter of touch" - because if they are not the blocks will fall the LRU list fairly quickly, if they do then the blocks could (after a few tablescans) eventually be promoted in half hot from the cache.

I did some quick tests (that requires a little care in the Installer) which suggest the number touch was not incremented has therefore not had any effect on the question of if the block would get preferential treatment when they have reached the end of the LRU.

I'm a little puzzled by your expression: "cached on LRU or MRU list" - it's not two different lists; but people talk about "the end of the MRU of the LRU list.

Concerning

Jonathan Lewis

While trying to see Planner installation and operation, the test in local mode, the EXECUTION fails with message "Waiting for the number of virtual machines to register.

While trying to see installation and operation Planner, the test in local mode with only 1 VM the EXECUTION fails with message "Waiting for the number of virtual machines to register.

There may be a lot of problems in the desktop VM. Agent service see Planner is not running in VM Office. You can check in the event viewer to see what kind of error occurs. The most usual error missing file IP.txt c; drive or harness IP in the IP.txt produce if there is.

get the structure of the event inside the while loop to wait for event occurs before the execution

Hello

I have a small problem, when I raise an event using a value change button, which works very well. The problem is that the VI does not wait for me raise an event and instead runs the same event again, even if I have not pressed the button to start again. The mechanical action of the button switch is released is.

I was wondering how you get the structure of the event to wait for a user event, after that he executed the first time.

James.Morris wrote:

There is no reason that the event should be raised twice as much that the only way that it fires in your code is by the user by clicking on 'Hall measure only'.

Oh yes, there is, and I deserve a kudo for this one. Mechanical action on the button is set on the switch until published, so click to generate an event, on the bottom and on the square, attached is an example.

My boy has my students hate this question, and to be honest, I hated it. When never would you do that intentionally? Honestly? Anyway to change the button back to normal (as default latch when released) and move the terminal button in the structure of the event where it is managed and it will work as usual.

What happened to the menus file, edit and view for mac 0s10.8.3? F10 and other solutions do not work? ESN can't work

I just got a new mac OS 10.8.3 and newest firefox. I can't find the menu bar, I can't close without force quiting, can't even tell what version I have. Whenever I try to use the arrows to change as suggested display full screen makes it worse. I have studied the subject and tried the fixes recommended as F10, optionF, etc., and nothing works. Help, please?

Make sure that you run not Firefox mode full screen (press F11 or Fn + F11 to toggle; Mac: Command + SHIFT + F).
- https://support.Mozilla.org/KB/how-to-use-full-screen
Try to remove the plist of Firefox (org.mozilla.firefox.plist).
- http://www.MacFixIt.com/article.php?story=20060606082246983 how the .plist files become corrupted and results troubleshooting
Go to "~/Library/Preferences" and delete the plist for Firefox (org.mozilla.firefox.plist)

The system file is not suitable for running ms - dos and microsoft windows applications

Hi, this is the error message when I try to install DUNE200 in and an old computer with windows XP.
Is there anything I can do to get his execution please?
Thank you

Hi eileenjune,

Welcome to the Microsoft Answers community.

This problem may occur if one or both of the following files are missing or corrupted:

1 Config.nt

2 Autoexec.nt

Try the steps below and let me know if this helped.

1. double-click 'My Computer' then your hard drive (probably drive C) and open the folder "WINDOWS".

2. open the folder "repair". Find "autoexec.nt" and "config.nt" in there. Copy these files (Ctrl + C) then go to C:\WINDOWS\SYSTEM32 and paste them there (Ctrl + V). It will ask you if you want to replace the old.

3. click on 'yes '.

4. now check if the problem persists.

For more information visit http://support.microsoft.com/kb/324767hope, this information is useful. \

Let me know if it worked.

Thank you, and in what concerns:
Umesh P - Microsoft Support
Visit our Microsoft answers feedback Forum and let us know what you think.

How to force the jad file to be regenerated for each version

I use Eclipse with the BlackBerry plugin. Whenever I build the project active BlackBerry (Alt + B), it seems that Eclipse rewrites the file jad (the timestamp on the changes to the file), but the contents of the jad file is not re-written!

I use the version string in the BlackBerry project properties to contain the version of my program. But I find that even if I change the version string in the Properties window (and I can verify that the value has changed by looking in the file jdp), when I build the active project of BlackBerry, the MIDlet-Version string in the jad file does not change. Yet if I delete the jad file and rebuild the project BB, then the jad file is written with the correct version string.

It would be really nice if the build has successfully written the jad file, but short, how can I automatically have the deleted jad file? As a matter of procedure, I usually do a project to clean and build together, before you build the active project BB. Is it possible to change the Eclipse-specific procedure to remove the old jad file? Is there a solution other/better?

In addition, RIM - the fact that you do not write correctly the version string for the jad is a BUG!

Thanks for the reply, but no, this link was not helpful. There is no what I already know and have already said, with one exception - the problem, they talked was in the JDE and they suggested using the plugin - BAD NEWS - the plugin has the same BUG.

What I did to make it work, it is write a cmd file that removes the jad and a few other files and set the absolute path to the cmd in the field of pre-build of project properties. NOTE that the commands of the del in the cmd file must all also the absolute path. I tried initially have an order of cd's as the first line of the cmd file, but that has not changed the directory - all the following commands continued to be run from the directory where the file of jdw. I also tried put an led with an absolute path command in the field of pre-build directly (rather than using a cmd file). Any work the del command.

Lightroom could not prepare the selected file to... for the edition. It will not open

Hello
I am trying to open an image in Photoshop from Lightroom, but recently I get this error message. can anyone help?
Thank you so much in advance.
Andrew

This could be due to a corrupted preferences file. This file can go 'funny' and is then responsible for all types of strange behavior of Lr. The repair is to replace the preferences file.

BTW: Resettlement Lr does not replace the file prefs, since it seeks to 'survive' updates.

See here for where to find the preferences for your operating system file: http://helpx.adobe.com/lightroom/kb/preference-file-locations-lightroo m - 4.html

See here to see how to replace the file preferably: http://lightroomers.com/replacing-the-lightroom-preference-file/745/

During the installation of FF10 in W7, the installation will stop after having extracted the installation files. Also happens for FF9.

I want to install Firefox 10 in W7. He extracted the installation files, and then wonder under what name/user I want to install; or as a current user as an administrator (which is strange, because the current user IS administrator). Which option to choose here, the installation is interrupted. Windows Task Manager displays just the judgment of trial. The same thing happens with FF9, what's up? I want to install Firefox 10 in W7. He extracted the installation files, and then wonder under what name/user I want to install; or as a current user as an administrator (which is strange, because the current user IS administrator). Which option to choose here, the installation is interrupted. Windows Task Manager displays just the judgment of trial. The same thing happens with FF9, what's up?

I'm glad you solved.

I am new to Windows 7, having already used XP but I seem to remember that type UAC guests can have a flashed up in an account Admin, while the installation of Firefox, but then just process at the facility without me having to explicitly a password or something.

I note our standardized instructions
- How to download and install Firefox on Windows
do not mention something special you need to ' right click > open as administrator ' in W7

the .psd file size is meaningless for me

I hope someone can explain the size of the huge .psd files that I see.
I have a Canon 7 d and shoot first. I have a raw file that is 24.6 MB and is a pixel image 3456 x 5184. I then open with ACR and do nothing but save it as a file .psd of 16 bits with the same image resolution (pixels). The .psd file is 102.5 MB.
By my Calc a 3456 x 5184 x 2 bytes (16 bits) is 35.8 MB uncompressed. Yet the .psd is nearly 3 times that size before it is already open in Photoshop.
Can anyone explain why? My 256 GB drive ate like a bunch of breath mint...

Your assumptions are false.

the "16 bit" RGB data have 3 colors per pixel bits x 16 per color. Thus, 3456 x 5184 x 6 bytes = 107 MB and change.

The raw file, I remember well, 14 bits per photosite of measurement data that has not been debayered. The scope that one color of light is measured by photosite.

Canon CR2 raw format and both include the Photoshop PSD format and compression without loss.

I hope this helps clear of the things up.

-Christmas

In the browser of Muse CC edition there was a problem reading the manifest file Adobe Muse CC for the site - how to fix this?

I just uploaded the site via the built in ftp upload in muse he then uploaded successfully. When I go in the edition of the browser and enter the name of the site (mernaliddawi.com) it says then this "there was a problem reading the file of Adobe Muse CC manifest for the site. Since Adobe Muse CC use file > load on the FTP host... to export the new site. ' I then exported the site again, but it still does not work also, I went my hosting provider file manager and deleted the file muse_mainfest.xml and then re uploaded still no chance. " How can I fix this thank you, james.

You need to transfer your domain to your new site. At present, the URL http://mernaliddawi.com/ is a web page that encapsulates the http://mernaliddawicom.ipage.com/ in a frameset. This isn't how a domain is successfully transferred. He doesn't bother with editing in the browser, will prevent redirection to versions Tablet and phone of your site (if you create), and can cause other problems.

If you enter mernaliddawicom.ipage.com to inbrowserediting.adobe.com it will not work, because this is the URL where your site is currently hosted.

Where are stored the audio files in Windows Vista (for example the alert sounds Windows Live, etc.)?

Hello. I would change one or two of my audio files Windows Vista message alerts (kind of like "You have a message", etc.) and I didn't something like this for a few years and on a latest version of Windows (XP). Please can someone tell me how and where I store files new sounds and how to install as new alerts?

Thank you for spending a few moments to read this.

Hi MartinUnderwood,

To use a custom sound when mail is delivered with Microsoft Outlook, Windows Live Mail, Windows Mail and Outlook Express:

a. Select Control Panel from the Start menu.

b. make sure you are in Classic view.

c. double-click on sounds and Audio devices.

d. go to the sounds tab.

e. highlight the New mail Notification in the program events list.

f. Select a sound in the sounds list, or use the Browse button to find a sound not in the list.

g. click apply and OK.

Hope this information helps.

"the db file sequential read" waiting for event slow down an application.

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