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.

Tags: Database

Similar Questions

"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

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

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

Can't make the default program for PDF files Adobe Reader 9

Hello. I have trouble changing the default program for the pdf files of Adobe Reader 9. Whenever I select the program, it does not appear. I'd appreciate any help. Thank you.

Sorry to resurrect an old thread, but here is your solution:

Regedit > HKEY_CLASSES_ROOT > Applications > AcroRd32.exe > shell > open > command

Right click > edit

Change your version to the latest version number:

"C:\Program Files (x 86) \Adobe\Reader" '%1'--> ' C:\Program Files (x 86) \Adobe\Reader 10.0\Reader\AcroRd32.exe "'%1 '.

DB file scattered read with Free (CBC) latch wait events

Hi all

On our production database server, we found about 50 sessions in lock Free (CBC) wait wait event with about 30 sessions waiting for db file scattered read... Also, the CPU load was obviously very high(90-99%).

Our server has 4 CPU and OS is HP - UX
Oracle version: 8.1.6.0.0
The optimizer mode is RULE

We found all sessions waiting performing this query below:

(SELECT /*+ORDERED*/
        ud.user_id,
        DECODE (udl.new_user_name,
                NULL, ud.user_name,
                udl.new_user_name
               ) AS user_name,
        udl.old_user_name, ud.PASSWORD, ud.status, au.first_name,
        au.last_name, sd.sd_id, sd.site_id, s.manager_number,
        sd.delivery_code, sd.site_server_id, au.email_address, au.outorg_id,
        udl.action_code, udl.action_category, udl.action_date AS action_date,
        au.admin_users_uid
   FROM user_delivery_log udl,
        user_delivery ud,
        appuser au,
       site_delivery sd,
        site_t s
  WHERE udl.action_date BETWEEN TO_DATE ('04/21/2009 17/46/25',
                                         'MM/DD/YYYY HH24/MI/SS'
                                        )
                            AND TO_DATE ('04/21/2009 17/47/26',
                                         'MM/DD/YYYY HH24/MI/SS'
                                        )
    AND (   (udl.action_category = 'I' AND BITAND (udl.action_code, 8195) != 0
            )
         OR (udl.action_category = 'U' AND BITAND (udl.action_code, 2079) != 0
            )
        )
    AND udl.site_id != 0
    AND ud.user_id = udl.user_id
    AND ud.sd_id = udl.sd_id
   AND ud.user_id = au.user_id
    AND ud.sd_id = sd.sd_id
    AND sd.site_id = s.site_id
    AND (sd.delivery_code = 'AEN')
    AND (   udl.new_user_name IS NOT NULL
        OR 0 =
               ((SELECT /*+ORDERED*/
                        COUNT (*)
                   FROM user_delivery_log udl1
                  WHERE udl1.action_date
                           BETWEEN TO_DATE ('04/21/2009 17/46/25',
                                            'MM/DD/YYYY HH24/MI/SS'
                                           )
                               AND TO_DATE ('04/21/2009 17/47/26',
                                           'MM/DD/YYYY HH24/MI/SS'
                                           )
                    AND (   (    udl1.action_category = 'I'
                             AND BITAND (udl1.action_code, 8195) != 0
                            )
                         OR (    udl1.action_category = 'U'
                             AND BITAND (udl1.action_code, 2079) != 0
                            )
                        )
                    AND udl1.site_id != 0
                    AND udl1.sd_id = ud.sd_id
                    AND udl1.user_id = ud.user_id
                    AND udl1.new_user_name IS NOT NULL))
        ))
UNION
(SELECT /*+ORDERED*/
        ud.user_id,
        DECODE (udl.new_user_name,
                NULL, ud.user_name,
                udl.new_user_name
               ) AS user_name,
        NULL AS old_user_name, ud.PASSWORD, ud.status, au.first_name,
        au.last_name, sd.sd_id, sd.site_id, s.manager_number,
        sd.delivery_code, sd.site_server_id, au.email_address, au.outorg_id,
        1536, 'U', udl.action_date AS action_date, au.admin_users_uid
   FROM user_delivery_log udl,
        user_delivery ud,
        appuser au,
        site_delivery sd,
        site_t s
  WHERE (udl.user_id, udl.action_date) IN (
           SELECT   udl.user_id, MAX (action_date)
               FROM user_delivery_log udl
              WHERE udl.action_date <
                       TO_DATE ('04/21/2009 17/46/25',
                                'MM/DD/YYYY HH24/MI/SS')
                AND (   (    udl.action_category = 'I'
                         AND BITAND (udl.action_code, 8195) != 0
                        )
                     OR (    udl.action_category = 'U'
                         AND BITAND (udl.action_code, 2079) != 0
                        )
                    )
                AND udl.user_id IN (
                       SELECT user_id
                         FROM appuser_log aul
                        WHERE aul.action_date
                                 BETWEEN TO_DATE ('04/21/2009 17/46/25',
                                                  'MM/DD/YYYY HH24/MI/SS'
                                                )
                                     AND TO_DATE ('04/21/2009 17/47/26',
                                                  'MM/DD/YYYY HH24/MI/SS'
                                                 )
                          AND aul.action_category = 'U'
                          AND BITAND (aul.action_code, 5632) != 0)
                AND udl.new_user_name IS NOT NULL
           GROUP BY user_id)
    AND udl.site_id != 0
    AND 0 =
           (SELECT COUNT (*)
              FROM user_delivery_log udl, site_delivery sd
             WHERE udl.action_date BETWEEN TO_DATE ('04/21/2009 17/46/25',
                                                    'MM/DD/YYYY HH24/MI/SS'
                                                   )
                                       AND TO_DATE ('04/21/2009 17/47/26',
                                                    'MM/DD/YYYY HH24/MI/SS'
                                                   )
               AND (   (    udl.action_category = 'I'
                       AND BITAND (udl.action_code, 8195) != 0
                       )
                    OR (    udl.action_category = 'U'
                        AND BITAND (udl.action_code, 2079) != 0
                       )
                   )
               AND udl.site_id != 0
              AND udl.sd_id = sd.sd_id
               AND udl.user_id = au.user_id
               AND (sd.delivery_code = 'AEN'))
    AND ud.user_id = au.user_id
    AND ud.user_id = udl.user_id
    AND ud.sd_id = sd.sd_id
    AND sd.site_id = s.site_id
    AND (sd.delivery_code = 'AEN'))
ORDER BY action_date ASC;

Below is the execution plan:
Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=RULE (Cost=341 Card=3 Bytes=312)
   1    0   SORT (UNIQUE) (Cost=342 Card=3 Bytes=312)
   2    1     UNION-ALL
   3    2       CONCATENATION
   4    3         FILTER
   5    4           NESTED LOOPS (Cost=12 Card=1 Bytes=100)
   6    5             NESTED LOOPS (Cost=11 Card=1 Bytes=94)
   7    6               NESTED LOOPS (Cost=10 Card=1 Bytes=77)
  8    7                 NESTED LOOPS (Cost=8 Card=1 Bytes=52)
   9    8                   TABLE ACCESS (BY INDEX ROWID) OF 'USER_DEL
          IVERY_LOG' (Cost=4 Card=2 Bytes=58)
  10    9                     INDEX (RANGE SCAN) OF 'IE1_USER_DELIVERY
          _LOG' (NON-UNIQUE) (Cost=3 Card=2)
  11    8                   TABLE ACCESS (BY INDEX ROWID) OF 'USER_DEL
          IVERY' (Cost=2 Card=1192563 Bytes=27428949)
  12   11                     INDEX (UNIQUE SCAN) OF 'IDX_PK_INV_USER_
          SD_ID' (UNIQUE) (Cost=1 Card=1192563)
  13    7                 TABLE ACCESS (BY INDEX ROWID) OF 'APPUSER' (
          Cost=2 Card=863102 Bytes=21577550)
  14   13                   INDEX (UNIQUE SCAN) OF 'PK_APPUSER' (UNIQU
          E) (Cost=1 Card=863102)
  15    6               TABLE ACCESS (BY INDEX ROWID) OF 'SITE_DELIVER
          Y' (Cost=1 Card=3494 Bytes=59398)
  16   15                 INDEX (UNIQUE SCAN) OF 'PK_NEW_SITE_DELIVERY
          ' (UNIQUE)
  17    5             TABLE ACCESS (BY INDEX ROWID) OF 'SITE_T' (Cost=
          1 Card=64113 Bytes=384678)
  18   17               INDEX (UNIQUE SCAN) OF 'PK_SITE_T' (UNIQUE)
  19    4           TABLE ACCESS (BY INDEX ROWID) OF 'USER_DELIVERY_LO
          G' (Cost=6 Card=1 Bytes=27)
  20   19             INDEX (RANGE SCAN) OF 'IE1_USER_DELIVERY_LOG' (N
          ON-UNIQUE) (Cost=3 Card=1)
  21    3         FILTER
  22   21           NESTED LOOPS (Cost=12 Card=1 Bytes=100)
  23   22             NESTED LOOPS (Cost=11 Card=1 Bytes=94)
  24   23               NESTED LOOPS (Cost=10 Card=1 Bytes=77)
  25   24                 NESTED LOOPS (Cost=8 Card=1 Bytes=52)
  26   25                   TABLE ACCESS (BY INDEX ROWID) OF 'USER_DEL
          IVERY_LOG' (Cost=4 Card=2 Bytes=58)
  27   26                     INDEX (RANGE SCAN) OF 'IE1_USER_DELIVERY
         _LOG' (NON-UNIQUE) (Cost=3 Card=2)
  28   25                   TABLE ACCESS (BY INDEX ROWID) OF 'USER_DEL
          IVERY' (Cost=2 Card=1192563 Bytes=27428949)
  29   28                     INDEX (UNIQUE SCAN) OF 'IDX_PK_INV_USER_
          SD_ID' (UNIQUE) (Cost=1 Card=1192563)
  30   24                 TABLE ACCESS (BY INDEX ROWID) OF 'APPUSER' (
          Cost=2 Card=863102 Bytes=21577550)
  31   30                   INDEX (UNIQUE SCAN) OF 'PK_APPUSER' (UNIQU
         E) (Cost=1 Card=863102)
  32   23               TABLE ACCESS (BY INDEX ROWID) OF 'SITE_DELIVER
          Y' (Cost=1 Card=3494 Bytes=59398)
  33   32                 INDEX (UNIQUE SCAN) OF 'PK_NEW_SITE_DELIVERY
          ' (UNIQUE)
  34   22             TABLE ACCESS (BY INDEX ROWID) OF 'SITE_T' (Cost=
          1 Card=64113 Bytes=384678)
  35   34               INDEX (UNIQUE SCAN) OF 'PK_SITE_T' (UNIQUE)
  36    2       NESTED LOOPS (Cost=314 Card=1 Bytes=112)
  37   36         NESTED LOOPS (Cost=313 Card=1 Bytes=106)
  38   37           NESTED LOOPS (Cost=312 Card=1 Bytes=89)
  39   38             NESTED LOOPS (Cost=310 Card=1 Bytes=64)
  40   39               NESTED LOOPS (Cost=306 Card=1 Bytes=41)
  41   40                 VIEW OF 'VW_NSO_1' (Cost=302 Card=1 Bytes=22
          )
  42   41                   SORT (GROUP BY) (Cost=302 Card=1 Bytes=35)
  43   42                     NESTED LOOPS (Cost=299 Card=1 Bytes=35)
  44   43                       TABLE ACCESS (FULL) OF 'APPUSER_LOG' (
          Cost=93 Card=1 Bytes=16)
  45   43                       TABLE ACCESS (FULL) OF 'USER_DELIVERY_
          LOG' (Cost=206 Card=73505 Bytes=1396595)
  46   40                 TABLE ACCESS (BY INDEX ROWID) OF 'USER_DELIV
          ERY_LOG' (Cost=4 Card=429251 Bytes=8155769)
  47   46                   INDEX (RANGE SCAN) OF 'IE1_USER_DELIVERY_L
          OG' (NON-UNIQUE) (Cost=3 Card=429251)
  48   39               TABLE ACCESS (BY INDEX ROWID) OF 'USER_DELIVER
         Y' (Cost=4 Card=1192563 Bytes=27428949)
  49   48                 INDEX (RANGE SCAN) OF 'IDX_PK_INV_USER_SD_ID
          ' (UNIQUE) (Cost=3 Card=1192563)
  50   38             TABLE ACCESS (BY INDEX ROWID) OF 'APPUSER' (Cost
          =2 Card=43156 Bytes=1078900)
  51   50               INDEX (UNIQUE SCAN) OF 'PK_APPUSER' (UNIQUE) (
          Cost=1 Card=43156)
  52   51                 NESTED LOOPS (Cost=7 Card=1 Bytes=31)
  53   52                   TABLE ACCESS (BY INDEX ROWID) OF 'USER_DEL
         IVERY_LOG' (Cost=6 Card=1 Bytes=24)
  54   53                     INDEX (RANGE SCAN) OF 'IE1_USER_DELIVERY
          _LOG' (NON-UNIQUE) (Cost=3 Card=1)
  55   52                   TABLE ACCESS (BY INDEX ROWID) OF 'SITE_DEL
          IVERY' (Cost=1 Card=3494 Bytes=24458)
  56   55                     INDEX (UNIQUE SCAN) OF 'PK_NEW_SITE_DELI
          VERY' (UNIQUE)
  57   37           TABLE ACCESS (BY INDEX ROWID) OF 'SITE_DELIVERY' (
          Cost=1 Card=3494 Bytes=59398)
  58   57             INDEX (UNIQUE SCAN) OF 'PK_NEW_SITE_DELIVERY' (U
          NIQUE)
  59   36         TABLE ACCESS (BY INDEX ROWID) OF 'SITE_T' (Cost=1 Ca
          rd=64113 Bytes=384678)
  60   59           INDEX (UNIQUE SCAN) OF 'PK_SITE_T' (UNIQUE)

For a clear view of the execution plan:

Plan Table
--------------------------------------------------------------------------------------------------------
| Operation                 |  Name    |  Rows | Bytes|  Cost  | Pstart| Pstop |
--------------------------------------------------------------------------------
| SELECT STATEMENT          |          |     3 |  312 |    341 |       |       |
|  SORT UNIQUE              |          |     3 |  312 |    342 |       |       |
|   UNION-ALL               |          |       |      |        |       |       |
|    CONCATENATION          |          |       |      |        |       |       |
|     FILTER                |          |       |      |        |       |       |
|      NESTED LOOPS         |          |     1 |  100 |     12 |       |       |
|       NESTED LOOPS        |          |     1 |   94 |     11 |       |       |
|        NESTED LOOPS       |          |     1 |   77 |     10 |       |       |
|         NESTED LOOPS      |          |     1 |   52 |      8 |       |       |
|          TABLE ACCESS BY I|USER_DELI |     2 |   58 |      4 |       |       |
|           INDEX RANGE SCAN|IE1_USER_ |     2 |      |      3 |       |       |
|          TABLE ACCESS BY I|USER_DELI |     1M|   26M|      2 |       |       |
|           INDEX UNIQUE SCA|IDX_PK_IN |     1M|      |      1 |       |       |
|         TABLE ACCESS BY IN|APPUSER   |   863K|   20M|      2 |       |       |
|          INDEX UNIQUE SCAN|PK_APPUSE |   863K|      |      1 |       |       |
|        TABLE ACCESS BY IND|SITE_DELI |     3K|   58K|      1 |       |       |
|         INDEX UNIQUE SCAN |PK_NEW_SI |     3K|      |        |       |       |
|       TABLE ACCESS BY INDE|SITE_T    |    64K|  375K|      1 |       |       |
|        INDEX UNIQUE SCAN  |PK_SITE_T |    64K|      |        |       |       |
|      TABLE ACCESS BY INDEX|USER_DELI |     1 |   27 |      6 |       |       |
|       INDEX RANGE SCAN    |IE1_USER_ |     1 |      |      3 |       |       |
|     FILTER                |          |       |      |        |       |       |
|      NESTED LOOPS         |          |     1 |  100 |     12 |       |       |
|       NESTED LOOPS        |          |     1 |   94 |     11 |       |       |
|        NESTED LOOPS       |          |     1 |   77 |     10 |       |       |
|         NESTED LOOPS      |          |     1 |   52 |      8 |       |       |
|          TABLE ACCESS BY I|USER_DELI |     2 |   58 |      4 |       |       |
|           INDEX RANGE SCAN|IE1_USER_ |     2 |      |      3 |       |       |
|          TABLE ACCESS BY I|USER_DELI |     1M|   26M|      2 |       |       |
|           INDEX UNIQUE SCA|IDX_PK_IN |     1M|      |      1 |       |       |
|         TABLE ACCESS BY IN|APPUSER   |   863K|   20M|      2 |       |       |
|          INDEX UNIQUE SCAN|PK_APPUSE |   863K|      |      1 |       |       |
|        TABLE ACCESS BY IND|SITE_DELI |     3K|   58K|      1 |       |       |
|         INDEX UNIQUE SCAN |PK_NEW_SI |     3K|      |        |       |       |
|       TABLE ACCESS BY INDE|SITE_T    |    64K|  375K|      1 |       |       |
|        INDEX UNIQUE SCAN  |PK_SITE_T |    64K|      |        |       |       |
|    NESTED LOOPS           |          |     1 |  112 |    314 |       |       |
|     NESTED LOOPS          |          |     1 |  106 |    313 |       |       |
|      NESTED LOOPS         |          |     1 |   89 |    312 |       |       |
|       NESTED LOOPS        |          |     1 |   64 |    310 |       |       |
|        NESTED LOOPS       |          |     1 |   41 |    306 |       |       |
|         VIEW              |VW_NSO_1  |     1 |   22 |    302 |       |       |
|          SORT GROUP BY    |          |     1 |   35 |    302 |       |       |
|           NESTED LOOPS    |          |     1 |   35 |    299 |       |       |
|            TABLE ACCESS FU|APPUSER_L |     1 |   16 |     93 |       |       |
|            TABLE ACCESS FU|USER_DELI |    73K|    1M|    206 |       |       |
|         TABLE ACCESS BY IN|USER_DELI |   429K|    7M|      4 |       |       |
|          INDEX RANGE SCAN |IE1_USER_ |   429K|      |      3 |       |       |
|        TABLE ACCESS BY IND|USER_DELI |     1M|   26M|      4 |       |       |
|         INDEX RANGE SCAN  |IDX_PK_IN |     1M|      |      3 |       |       |
|       TABLE ACCESS BY INDE|APPUSER   |    43K|    1M|      2 |       |       |
|        INDEX UNIQUE SCAN  |PK_APPUSE |    43K|      |      1 |       |       |
|         NESTED LOOPS      |          |     1 |   31 |      7 |       |       |
|          TABLE ACCESS BY I|USER_DELI |     1 |   24 |      6 |       |       |
|           INDEX RANGE SCAN|IE1_USER_ |     1 |      |      3 |       |       |
|          TABLE ACCESS BY I|SITE_DELI |     3K|   23K|      1 |       |       |
|           INDEX UNIQUE SCA|PK_NEW_SI |     3K|      |        |       |       |
|      TABLE ACCESS BY INDEX|SITE_DELI |     3K|   58K|      1 |       |       |
|       INDEX UNIQUE SCAN   |PK_NEW_SI |     3K|      |        |       |       |
|     TABLE ACCESS BY INDEX |SITE_T    |    64K|  375K|      1 |       |       |
|      INDEX UNIQUE SCAN    |PK_SITE_T |    64K|      |        |       |       |
--------------------------------------------------------------------------------

All the locks of CBC point to the APPUSER_LOG and USER_DELIVERY_LOG tables.
Could someone help me please in the setting of this query, I need to avoid latch and scattered read... .as application knows huge slow...

-Yasser

YasserRACDBA wrote:

Oracle version: 8.1.6.0.0
The optimizer mode is RULE

We found all sessions waiting performing this query below:
(SELECT /*+ORDERED*/

Even if you run based on rules in general, this query will run based on costs due to the indicator.
Do you have statistics in place to support the OBC?

| VIEW |VW_NSO_1 | 1 | 22 | 302 | | | | SORT GROUP BY | | 1 | 35 | 302 | | | | NESTED LOOPS | | 1 | 35 | 299 | | | | TABLE ACCESS FU|APPUSER_L | 1 | 16 | 93 | | | | TABLE ACCESS FU|USER_DELI | 73K| 1M| 206 | | |

This is typical of an unnested "IN" subquery - it looks like the optimiser has unnested your double-level IN subquery finding the maximum action date for a user who has done something in the last minute into a massive group and aggregate (so we've got unnesting and complex view merging all in one - I don't think I've seen that in 8i before).


Your db file scattered reads are probably extreme because (a) the USER_DELIxxxx table is big, and (b) the number of rows you are getting from the APPUSER_Lxxx table is more than the one that Oracle expects. You may find that collecting stats on APPUSER_Lxxx addresses this issue
I can't see any reason why the appuser_log table should be subject to cache buffers chains latch problems - if the plan is true than the only thing it suffers is one full scan. However, given the "one row" estimate that comes out of the VW_NOS_1 line, the optimizer is free to do all sorts of silly things as it works through the chain of nested loops, and if the number of rows from the driver is much more than one then the indexed activity against USER_DELIxxx could be huge.

For example:

|         TABLE ACCESS BY IN|USER_DELI |   429K|    7M|      4 |       |       |
|          INDEX RANGE SCAN |IE1_USER_ |   429K|      |      3 |       |       |

Is the next step in this nested loop (and similar things happen more down and in the previous sections of the plan) suggesting that a systematic index scan rnage will pick up thousands of lines - which, even if only about right, could mean a huge number of buffer visits to the table. ... the numbers don't make real sense, either by the way, but once again, it is probably due to the lack of appropriate statistics.

Concerning
Jonathan Lewis
http://jonathanlewis.WordPress.com
http://www.jlcomp.demon.co.UK

"Science is more than a body of knowledge; It's a way of thinking. "
Carl Sagan

session hung on db file scattered read

Hello everyone, I'm on 10.2.0.3. Looks like the session is hung... here is the output of the Sub sql...
Select the State seq #, event, seconds_in_wait from v$ session_wait where sid = 194;

STATE                     SEQ#
------------------- ----------
EVENT                                                            SECONDS_IN_WAIT
---------------------------------------------------------------- ---------------
WAITED SHORT TIME         1487
db file scattered read                                                      3143

then when I check what is blocking, file its waiting on... It is waiting on the same file/block for a long time...
Select the sid, event, State, seq #, seconds_in_wait, p1, p2, p3
v $ session_wait
where sid = 194;

       SID EVENT                                                           
---------- ----------------------------------------------------------------
STATE                     SEQ# SECONDS_IN_WAIT         P1         P2         P3
------------------- ---------- --------------- ---------- ---------- ----------
       194 db file scattered read                                          
WAITED SHORT TIME         1487            3296         13         89          6

What can we do to debug this? or find why it takes so long to read this block? is the block corrupted or something?

7/8 =.875 = 87.5% unused. Translated, that means that one of the processors is pegged to near 100% usage (possibly by a single session). You can take a look in V$ SESSION view the SQL_ID, the SQL_CHILD_NUMBER and the SQL_ADDRESS, and to search for this SQL statement in V$ SQLSTATS or V$ SQL (this view will display the SQL text). It could be that the query uses a Cartesian join which resulted in an execution plan wrong perhaps due to a missing join condition. You will probably see the CPU_TIME and the BUFFER_GETS (compatible GETS) is growing rapidly. You can then use DBMS_XPLAN to plan for the SQL_ID and CHILD_NUMBER to check if a Cartesian join is listed in the exit plan.

Charles Hooper
IT Manager/Oracle DBA
K & M-making Machine, Inc.

How can I change the values of control based on a file of reading?

I understand that the controls were only outputs and indicators has only entries, but I'm looking for help to create code that has the capabilities of both. More specifically and, ideally, my façade would allow the user to select an old spreadsheet file to read, and these values of the worksheet would be poster. The user could then change these values to their liking and then submit those twisted values, such as a new file / replaces the old/etc. The important part is the the indicating and control playback in values.

Thank you

Need to wire the worksheet values in the local. The control itself just watches. What you have wired in your VI sets the control to its current value (of course, a bit pointless).

Since I compressed my NTFS drive last week, all the text of my files names are in blue. Is there a reason for this?

Original title: file names have turned to the Blues

file names have turned to the bruises on my dell hybrid. I compressed my NTFS drive week last to create more space and since then, all the names of txt on my files are now blue. is there a reason for this?

Hello JordanMcGinn,

Please see the link below regarding this issue.

File changed police in blue: it's normal - blue means that the file is compressed

http://answers.Microsoft.com/en-us/Windows/Forum/windows_vista-files/file-font-changed-to-blue/3efc8f58-edf8-4930-9e38-69feca448a92

Thank you

Windows 7 will not search my rtf files. I went into Control Panel and rich text is selected. I also tried adding again, but he will not always look for rtf files.

Windows 7 will not search my rtf files. I went into Control Panel and rich text is selected. I also tried adding again, but he will not always look for rtf files.

Hello

·         Is that what the problem is with a specific file extension?

·         How long have you been faced with this problem?

·         You did it last changes before the show?

Follow the steps below to solve the problem:

Method 1:

If you have problems of location of the files, folders, or other items on your computer, try using the search and indexing of troubleshooting to solve the problem. It ensures that the Windows Search service is running and checks if you have the correct permissions to search all the directories on your computer.

See the article below for additional information and steps.

Open the troubleshooter for search and indexing

http://Windows.Microsoft.com/en-us/Windows7/open-the-search-and-indexing-Troubleshooter

Method 2:

Also I ask you to re - index files and then check. Follow the artticle below for the procedure.

Change advanced indexing options

http://Windows.Microsoft.com/en-us/Windows7/change-advanced-indexing-options

See also:

Improve Windows searches using the index: frequently asked questions

http://Windows.Microsoft.com/en-us/Windows7/improve-Windows-searches-using-the-index-frequently-asked-questions

Hope this information helps.

How to prevent the appearance of "Failed to open Document" "Please check if you have read permissions for the file above. This problem occurs when I try to convert a word in a PDF doc.

How to prevent the appearance of "Failed to open Document" "Please check if you have read permissions for the file above? This problem occurs when I try to convert a word in a PDF doc.

Hi [email protected] ,

Please try to follow the steps mentioned in this thread with a similar problem: Impossible to open the document. Please check if you have read permissions for the above file.

Also, let us know the acrobat version you have and the version of the OS on your system.

Let us know if that helps.

Concerning
Sarojini

ORA-00205: error in the identification of control files, see log alerts for more information

Hello
I'm putting it on oracle 11.2.0.1 to 11.2.0.3 DB level but during DBUA, I got error
"ORA-00205: error in the identification of control files, check the log of alerts for more information.

I have check the alerts log in E:\app\kmahalingam\diag\rdbms\orcl\orcl\trace\alert_orcl.txt
Starting ORACLE instance (normal)
LICENSE_MAX_SESSION = 0
LICENSE_SESSIONS_WARNING = 0
SNA system picked latch-free 3
With the help of LOG_ARCHIVE_DEST_1 parameter value by default as USE_DB_RECOVERY_FILE_DEST
Autotune undo retention is enabled.
IMODE = BR
ILAT = 51
LICENSE_MAX_USERS = 0
SYS audit is disabled
Commissioning:
Oracle Database 11 g Enterprise Edition Release 11.2.0.3.0 - 64 bit Production
With the options of partitioning, OLAP, Data Mining and Real Application Testing.
Windows NT Version V6.1 Service Pack 1
UC: 8 - type 8664, 8 physical cores
Process affinity: 0 x 0 x 0000000000000000
Memory (success/Total): Ph: 3241 M / 16383 M, Ph + FCP: 16565 M / 32765 M
Using parameters in spfile E:\APP\KMAHALINGAM\PRODUCT\11.2.0\DBHOME_2\DATABASE\SPFILEORCL server-side. ORA
Parameters of the system with default values:
process = 300
sessions = 472
memory_target = 3280M
control_files = 'E:\APP\KMAHALINGAM\ORADATA\ORCL\CONTROL01. CTL.
control_files = 'E:\APP\KMAHALINGAM\FLASH_RECOVERY_AREA\ORCL\CONTROL02. CTL.
DB_BLOCK_SIZE = 8192
compatible = "11.2.0.0.0."
db_recovery_file_dest = 'E:\app\kmahalingam\flash_recovery_area. '
db_recovery_file_dest_size = 3912M
undo_tablespace = 'UNDOTBS1.
Remote_login_passwordfile = "EXCLUSIVE."
db_domain = "cpg.com."
dispatchers = "(PROTOCOL=TCP) (SERVICE = orclXDB)" "
audit_file_dest = "E:\APP\KMAHALINGAM\ADMIN\ORCL\ADUMP".
AUDIT_TRAIL = 'NONE '.
db_name = "orcl".
open_cursors = 300
star_transformation_enabled = 'TRUE '.
diagnostic_dest = "E:\APP\KMAHALINGAM".
Fri Mar 07 00:33:15 2014
PMON started with pid = 2, OS id = 25072
Fri Mar 07 00:33:15 2014
PSP0 started with pid = 3, OS id = 25688
Fri Mar 07 00:33:16 2014
VKTM started with pid = 4, OS id = 27608 high priority
VKTM clocked at (10) precision of milliseconds with DBRM quantum (100) ms
Fri Mar 07 00:33:16 2014
GEN0 started with pid = 5, OS id = 11484
Fri Mar 07 00:33:16 2014
DIAG started with pid = 6, OS id = 16980
Fri Mar 07 00:33:16 2014
DBRM started with pid = 7, OS id = 2200
Fri Mar 07 00:33:16 2014
DIA0 started with pid = 8, OS id = 8024
Fri Mar 07 00:33:16 2014
MA started with pid = 9, OS id = 15688
Fri Mar 07 00:33:16 2014
DBW0 started with pid = 10, OS id = 19908
Fri Mar 07 00:33:16 2014
LGWR started with pid = 11, OS id = 22616
Fri Mar 07 00:33:16 2014
CKPT started with pid = 12, OS id = 12828
Fri Mar 07 00:33:16 2014
SMON started with pid = 13, OS id = 10184
Fri Mar 07 00:33:16 2014
RECCE has started with pid = 14, OS id = 28984
Fri Mar 07 00:33:16 2014
MMON started with pid = 15, OS id = 22288
Fri Mar 07 00:33:16 2014
MMNL started with pid = 16, OS id = 12072
commissioning 1 dispatcher (s) for '(ADDRESS =(PARTIAL=YES) (PROTOCOL = TCP))' network address...
commissioning or shared server 1...
Environment ORACLE_BASE = E:\app\kmahalingam
Fri Mar 07 00:33:16 2014
ALTER DATABASE MOUNT
ORA-00210: could not open the specified control file
ORA-00202: control file: ' E:\APP\KMAHALINGAM\FLASH_RECOVERY_AREA\ORCL\CONTROL02. CTL'
ORA-27041: could not open the file
04002 - OSD: could not open the file
S/O-error: (OS 2) the system cannot find the file specified.
ORA-00210: could not open the specified control file
ORA-00202: control file: ' E:\APP\KMAHALINGAM\ORADATA\ORCL\CONTROL01. CTL'
ORA-27041: could not open the file
04002 - OSD: could not open the file
S/O-error: (OS 2) the system cannot find the file specified.
ORA - 205 marked during: ALTER DATABASE MOUNT...
Fri Mar 07 00:34:46 2014
ALTER DATABASE MOUNT
Fri Mar 07 00:34:46 2014
ORA-00210: could not open the specified control file
ORA-00202: control file: ' E:\APP\KMAHALINGAM\FLASH_RECOVERY_AREA\ORCL\CONTROL02. CTL'
ORA-27041: could not open the file
04002 - OSD: could not open the file
S/O-error: (OS 2) the system cannot find the file specified.
ORA-00210: could not open the specified control file
ORA-00202: control file: ' E:\APP\KMAHALINGAM\ORADATA\ORCL\CONTROL01. CTL'
ORA-27041: could not open the file
04002 - OSD: could not open the file
S/O-error: (OS 2) the system cannot find the file specified.
ORA - 205 marked during: ALTER DATABASE MOUNT...
Fri Mar 07 00:45:51 2014
change the database editing
Fri Mar 07 00:45:51 2014
ORA-00210: could not open the specified control file
ORA-00202: control file: ' E:\APP\KMAHALINGAM\FLASH_RECOVERY_AREA\ORCL\CONTROL02. CTL'
ORA-27041: could not open the file
04002 - OSD: could not open the file
S/O-error: (OS 2) the system cannot find the file specified.
ORA-00210: could not open the specified control file
ORA-00202: control file: ' E:\APP\KMAHALINGAM\ORADATA\ORCL\CONTROL01. CTL'
ORA-27041: could not open the file
04002 - OSD: could not open the file
S/O-error: (OS 2) the system cannot find the file specified.
ORA - 205 scored at the course: change the editing of the database...
Fri Mar 07 00:48:13 2014
change the database editing
Fri Mar 07 00:48:13 2014
ORA-00210: could not open the specified control file
ORA-00202: control file: ' E:\APP\KMAHALINGAM\FLASH_RECOVERY_AREA\ORCL\CONTROL02. CTL'
ORA-27041: could not open the file
04002 - OSD: could not open the file
S/O-error: (OS 2) the system cannot find the file specified.
ORA-00210: could not open the specified control file
ORA-00202: control file: ' E:\APP\KMAHALINGAM\ORADATA\ORCL\CONTROL01. CTL'
ORA-27041: could not open the file
04002 - OSD: could not open the file
S/O-error: (OS 2) the system cannot find the file specified.
ORA - 205 scored at the course: change the editing of the database...
Fri Mar 07 00:52:34 2014
Derives from detected time. Check the file path VKTM for more details.
Fri Mar 07 00:53:46 2014
Closure of proceedings (immediate)
Closure of proceedings: in addition to logons disabled
Stop background MMNL process
MMON background process stop
The high waters = 1 license
All dispatchers/dispatchers and shared servers stop
ALTER DATABASE CLOSE NORMAL
ORA-1507 marked during: ALTER DATABASE CLOSE NORMAL...
ARCH: Disabled archives due to the stop: 1089
Stop process to archive
Archiving is disabled
ARCH: Disabled archives due to the stop: 1089
Stop process to archive
Archiving is disabled
Fri Mar 07 00:53:49 2014
Stop background VKTM process
Fri Mar 07 00:53:51 2014
Instance shutdown complete
Fri Mar 07 00:54:01, 2014
Setting the default value of the parameter parallel_max_servers
320 to 285 because of the value of the process parameters (300)
Help, please
Thank you

According to spfile.

control_files = 'E:\APP\KMAHALINGAM\ORADATA\ORCL\CONTROL01. CTL.

control_files = 'E:\APP\KMAHALINGAM\FLASH_RECOVERY_AREA\ORCL\CONTROL02. CTL.

You mentioned

Davinapochon wrote:

E:\APP\KMAHALINGAM\ORADATA\ORCL\CONTROL02. CTL file is there but there is no CONTROL01. CTL file.

So little confused here.

E:\APP\KMAHALINGAM\ORADATA\ORCL\--> must contain CONTROL01. CTL

E:\APP\KMAHALINGAM\FLASH_RECOVERY_AREA\ORCL\--> must contain CONTROL02. CTL

What is it now?

Anand

When trying to download Windows Explorer, a bunch of my files (including web browsers) has been treated by my Acrobat Reader. This has also changed the icon for these files (including browsers). Could not change their return. Tried to uninstall a

That's happened? When trying to download Windows Explorer, a bunch of my files (including web browsers) has been treated by my Acrobat Reader. No idea how or why this has happened. This has also changed the icon for these files (including browsers). Could not change their return. Tried to uninstall and reinstall Acrobat Reader a few times. With Acrobat Reader installed now I can't open my browsers or other files that has changed. With Acrobat Reader uninstalled icons are appropriate and I can open the browsers, but other files may not always be open. What happened, and what I can do to use Acrobat Reader again and also use my browsers and open the other files?

You have tried to download Windows Explorer?

In any case, this might solve your problem: Application, file icons change in Acrobat/Reader icon

I have a panasonic G3 camera and already use 3 years lightroom for raw files, now I bought a new G7 and he can't read raw files in lightroom, to me terrible, that I update lr to 5.7

I have a panasonic G3 camera and already use 3 years lightroom for raw files, now I bought a new G7 and he can't read raw files in lightroom, to me terrible, that I update lr to 5.7

Move the discussion to Photoshop Lightroom

Reason for 'control file sequential read' wait?

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