Read By Other Session

Hi
Please help. The situation is that we found the Read By Other Sessions Event occurs and the sessions hang for a week. No new Sessions ID suffers from ths events and Just keep 10 Sessions ID with this event waiting. Our user didn't suffer any performance problem so far.
Our Application layer is Web-based, I believe users related to those sessions are disconnected already. So How come those session ID waits so long !!!!
Thx
Kit

Our DBA helped me to get the information from the V$Session. Let Session ID = 123. We found that this session has Read by Other Session" event from 17-May up to now every 10 seconds.
DBA gives me the following fields to study
Time
INSTANCE_NUMBER
SESSION_ID
DB User
EVENT_NAME
CURRENT_OBJ#
CURRENT_FILE#
CURRENT_BLOCK#
SEQ#
EVENT_ID P1 P2 P3
WAIT_TIME TIME_WAITED SQL_ID SQL_TEXT

Similar Messages

  • Performance issue showing read by other session Event

    Hi All,
    we are having a severe performance issue in my database when we are running batch jobs.
    This was a new database(11.2.0.2) and we are testing the performance by running some batch jobs. These batch jobs included some inserts and updates.
    I am seeing read by other session in top 5 timed events and cache buffers chains in Latch Miss Sources section.
    Please help me to solve this out.
    Inst Num Startup Time    Release     RAC
    1 27-Feb-12 09:03 11.2.0.2.0  NO
    Platform                         CPUs Cores Sockets Memory(GB)
    Linux x86 64-bit                    8     8       8      48.00           
    Snap Id      Snap Time      Sessions Curs/Sess
    Begin Snap:      5605 29-Feb-12 03:00:27        63       4.5
      End Snap:      5614 29-Feb-12 12:00:47        63       4.3
       Elapsed:              540.32 (mins)
       DB Time:            1,774.23 (mins)
    Cache Sizes                       Begin        End
    ~~~~~~~~~~~                  ---------- ----------
                   Buffer Cache:     1,952M     1,952M  Std Block Size:        16K
               Shared Pool Size:     1,024M     1,024M      Log Buffer:    18,868K
    Load Profile              Per Second    Per Transaction   Per Exec   Per Call
    ~~~~~~~~~~~~         ---------------    --------------- ---------- ----------
          DB Time(s):                3.3                0.8       0.02       0.05
           DB CPU(s):                1.1                0.3       0.01       0.02
           Redo size:           55,763.8           13,849.3
       Logical reads:           23,906.6            5,937.4
       Block changes:              325.7               80.9
      Physical reads:              665.6              165.3
    Physical writes:               40.4               10.0
          User calls:               60.7               15.1
              Parses:               10.6                2.6
         Hard parses:                1.1                0.3
    W/A MB processed:                0.6                0.2
              Logons:                0.1                0.0
            Executes:              151.2               37.6
           Rollbacks:                0.0                0.0
        Transactions:                4.0
    Instance Efficiency Percentages (Target 100%)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                Buffer Nowait %:   99.94       Redo NoWait %:  100.00
                Buffer  Hit   %:   97.90    In-memory Sort %:  100.00
                Library Hit   %:   98.06        Soft Parse %:   90.16
             Execute to Parse %:   92.96         Latch Hit %:  100.00
    Parse CPU to Parse Elapsd %:   76.71     % Non-Parse CPU:   98.57
    Shared Pool Statistics        Begin    End
                 Memory Usage %:   89.38   87.96
        % SQL with executions>1:   97.14   95.15
      % Memory for SQL w/exec>1:   96.05   92.46
    Top 5 Timed Foreground Events
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                                               Avg
                                                              wait   % DB
    Event                                 Waits     Time(s)   (ms)   time Wait Class
    db file sequential read          14,092,706      65,613      5   61.6 User I/O
    DB CPU                                           34,819          32.7
    read by other session               308,534       1,260      4    1.2 User I/O
    direct path read                     97,454         987     10     .9 User I/O
    db file scattered read               71,870         910     13     .9 User I/O
    Host CPU (CPUs:    8 Cores:    8 Sockets:    8)
    ~~~~~~~~         Load Average
                   Begin       End     %User   %System      %WIO     %Idle
                    0.43      0.36      13.7       0.6       9.7      85.7
    Instance CPU
    ~~~~~~~~~~~~
                  % of total CPU for Instance:      13.5
                  % of busy  CPU for Instance:      94.2
      %DB time waiting for CPU - Resource Mgr:       0.0
    Memory Statistics
    ~~~~~~~~~~~~~~~~~                       Begin          End
                      Host Mem (MB):     49,152.0     49,152.0
                       SGA use (MB):      3,072.0      3,072.0
                       PGA use (MB):        506.5        629.1
        % Host Mem used for SGA+PGA:         7.28         7.53
    Time Model Statistics             
    -> Total time in database user-calls (DB Time): 106453.8s
    -> Statistics including the word "background" measure background process
       time, and so do not contribute to the DB time statistic
    -> Ordered by % or DB time desc, Statistic name
    Statistic Name                                       Time (s) % of DB Time
    sql execute elapsed time                            105,531.1         99.1
    DB CPU                                               34,818.8         32.7
    parse time elapsed                                      714.7           .7
    hard parse elapsed time                                 684.8           .6
    PL/SQL execution elapsed time                           161.9           .2
    PL/SQL compilation elapsed time                          44.2           .0
    connection management call elapsed time                  16.9           .0
    hard parse (sharing criteria) elapsed time               10.2           .0
    hard parse (bind mismatch) elapsed time                   9.4           .0
    sequence load elapsed time                                2.9           .0
    repeated bind elapsed time                                0.5           .0
    failed parse elapsed time                                 0.0           .0
    DB time                                             106,453.8
    background elapsed time                               1,753.9
    background cpu time                                      61.7
    Operating System Statistics        
    -> *TIME statistic values are diffed.
       All others display actual values.  End Value is displayed if different
    -> ordered by statistic type (CPU Use, Virtual Memory, Hardware Config), Name
    Statistic                                  Value        End Value
    BUSY_TIME                              3,704,415
    IDLE_TIME                             22,203,740
    IOWAIT_TIME                            2,517,864
    NICE_TIME                                      3
    SYS_TIME                                 145,696
    USER_TIME                              3,557,758
    LOAD                                           0                0
    RSRC_MGR_CPU_WAIT_TIME                         0
    VM_IN_BYTES                      358,813,045,760
    VM_OUT_BYTES                      29,514,830,848
    PHYSICAL_MEMORY_BYTES             51,539,607,552
    NUM_CPUS                                       8
    NUM_CPU_CORES                                  8
    NUM_CPU_SOCKETS                                8
    GLOBAL_RECEIVE_SIZE_MAX                4,194,304
    GLOBAL_SEND_SIZE_MAX                   1,048,586
    TCP_RECEIVE_SIZE_DEFAULT                  87,380
    TCP_RECEIVE_SIZE_MAX                   4,194,304
    TCP_RECEIVE_SIZE_MIN                       4,096
    TCP_SEND_SIZE_DEFAULT                     16,384
    TCP_SEND_SIZE_MAX                      4,194,304
    TCP_SEND_SIZE_MIN                          4,096
    Operating System Statistics -
    Snap Time           Load    %busy    %user     %sys    %idle  %iowait
    29-Feb 03:00:27      0.4      N/A      N/A      N/A      N/A      N/A
    29-Feb 04:00:35      1.4     11.9     11.2      0.6     88.1     14.3
    29-Feb 05:00:41      1.7     13.8     13.2      0.6     86.2     15.8
    29-Feb 06:00:48      1.5     14.0     13.5      0.6     86.0     12.3
    29-Feb 07:01:00      1.8     16.3     15.8      0.5     83.7     10.4
    29-Feb 08:00:12      2.6     23.2     22.5      0.6     76.8     12.6
    29-Feb 09:00:26      1.3     16.6     16.0      0.5     83.4      5.7
    29-Feb 10:00:33      1.2     13.8     13.3      0.5     86.2      2.0
    29-Feb 11:00:43      1.3     14.5     14.0      0.5     85.5      3.8
    29-Feb 12:00:47      0.4      4.9      4.2      0.7     95.1     10.6
    Foreground Wait Class              
    -> s  - second, ms - millisecond -    1000th of a second
    -> ordered by wait time desc, waits desc
    -> %Timeouts: value of 0 indicates value was < .5%.  Value of null is truly 0
    -> Captured Time accounts for         97.9%  of Total DB time     106,453.79 (s)
    -> Total FG Wait Time:            69,415.64 (s)  DB CPU time:      34,818.79 (s)
                                                                      Avg
                                          %Time       Total Wait     wait
    Wait Class                      Waits -outs         Time (s)     (ms)  %DB time
    User I/O                   14,693,843     0           69,222        5      65.0
    DB CPU                                                34,819               32.7
    Commit                         40,629     0              119        3       0.1
    System I/O                     26,504     0               57        2       0.1
    Network                     1,945,010     0               11        0       0.0
    Other                         125,200    99                4        0       0.0
    Application                     2,673     0                2        1       0.0
    Concurrency                     3,059     0                1        0       0.0
    Configuration                      31    19                0       15       0.0
    Foreground Wait Events            
    -> s  - second, ms - millisecond -    1000th of a second
    -> Only events with Total Wait Time (s) >= .001 are shown
    -> ordered by wait time desc, waits desc (idle events last)
    -> %Timeouts: value of 0 indicates value was < .5%.  Value of null is truly 0
                                                                 Avg
                                            %Time Total Wait    wait    Waits   % DB
    Event                             Waits -outs   Time (s)    (ms)     /txn   time
    db file sequential read      14,092,706     0     65,613       5    108.0   61.6
    read by other session           308,534     0      1,260       4      2.4    1.2
    direct path read                 97,454     0        987      10      0.7     .9
    db file scattered read           71,870     0        910      13      0.6     .9
    db file parallel read            35,001     0        372      11      0.3     .3
    log file sync                    40,629     0        119       3      0.3     .1
    control file sequential re       26,504     0         57       2      0.2     .1
    direct path read temp            14,499     0         49       3      0.1     .0
    direct path write temp            9,186     0         28       3      0.1     .0
    SQL*Net message to client     1,923,973     0          5       0     14.7     .0
    SQL*Net message from dblin        1,056     0          5       5      0.0     .0
    Disk file operations I/O          8,848     0          2       0      0.1     .0
    ASM file metadata operatio           36     0          2      54      0.0     .0
    SQL*Net break/reset to cli        2,636     0          1       1      0.0     .0
    ADR block file read                 472     0          1       1      0.0     .0
    os thread startup                     8     0          1      74      0.0     .0
    SQL*Net more data to clien       17,656     0          1       0      0.1     .0
    asynch descriptor resize        123,852   100          0       0      0.9     .0
    local write wait                    110     0          0       4      0.0     .0
    utl_file I/O                     55,635     0          0       0      0.4     .0
    log file switch (private s            8     0          0      52      0.0     .0
    cursor: pin S wait on X               2     0          0     142      0.0     .0
    enq: KO - fast object chec           13     0          0      20      0.0     .0
    PX Deq: Slave Session Stat          248     0          0       1      0.0     .0
    enq: RO - fast object reus           18     0          0      11      0.0     .0
    latch: cache buffers chain        2,511     0          0       0      0.0     .0
    latch: shared pool                  195     0          0       1      0.0     .0
    CSS initialization                   12     0          0       8      0.0     .0
    PX qref latch                        54   100          0       2      0.0     .0
    SQL*Net more data from cli          995     0          0       0      0.0     .0
    SQL*Net more data from dbl          300     0          0       0      0.0     .0
    kksfbc child completion               1   100          0      56      0.0     .0
    library cache: mutex X              244     0          0       0      0.0     .0
    PX Deq: Signal ACK RSG              124     0          0       0      0.0     .0
    undo segment extension                6   100          0       7      0.0     .0
    PX Deq: Signal ACK EXT              124     0          0       0      0.0     .0
    library cache load lock               3     0          0       9      0.0     .0
    ADR block file write                 45     0          0       1      0.0     .0
    CSS operation: action                12     0          0       2      0.0     .0
    reliable message                     28     0          0       1      0.0     .0
    CSS operation: query                 72     0          0       0      0.0     .0
    latch: row cache objects             14     0          0       1      0.0     .0
    enq: SQ - contention                 17     0          0       0      0.0     .0
    latch free                           32     0          0       0      0.0     .0
    buffer busy waits                    52     0          0       0      0.0     .0
    enq: PS - contention                 16     0          0       0      0.0     .0
    enq: TX - row lock content            6     0          0       1      0.0     .0
    SQL*Net message to dblink         1,018     0          0       0      0.0     .0
    cursor: pin S                        23     0          0       0      0.0     .0
    latch: cache buffers lru c            8     0          0       0      0.0     .0
    SQL*Net message from clien    1,923,970     0    944,508     491     14.7
    jobq slave wait                  66,732   100     33,334     500      0.5
    Streams AQ: waiting for me        6,481   100     32,412    5001      0.0
    wait for unread message on       32,858    98     32,411     986      0.3
    PX Deq: Execution Msg             1,448     0        190     131      0.0
    PX Deq: Execute Reply             1,196     0         74      62      0.0
    HS message to agent                 228     0          4      19      0.0
    single-task message                  42     0          4      97      0.0
    PX Deq Credit: send blkd            904     0          2       3      0.0
    PX Deq Credit: need buffer          205     0          1       3      0.0
    Foreground Wait Events            
    -> s  - second, ms - millisecond -    1000th of a second
    -> Only events with Total Wait Time (s) >= .001 are shown
    -> ordered by wait time desc, waits desc (idle events last)
    -> %Timeouts: value of 0 indicates value was < .5%.  Value of null is truly 0
                                                                 Avg
                                            %Time Total Wait    wait    Waits   % DB
    Event                             Waits -outs   Time (s)    (ms)     /txn   time
    PX Deq: Table Q Normal            4,291     0          1       0      0.0
    PX Deq: Join ACK                    124     0          0       1      0.0
    PX Deq: Parse Reply                 124     0          0       0      0.0
    KSV master wait                     256     0          0       0      0.0
    Latch Miss Sources                
    -> only latches with sleeps are shown
    -> ordered by name, sleeps desc
                                                         NoWait              Waiter
    Latch Name               Where                       Misses     Sleeps   Sleeps
    ASM map operation freeli kffmTranslate2                   0          2        0
    DML lock allocation      ktadmc                           0          2        0
    FOB s.o list latch       ksfd_allfob                      0          2        2
    In memory undo latch     ktiFlushMe                       0          5        0
    In memory undo latch     ktichg: child                    0          3        0
    PC and Classifier lists  No latch                         0          6        0
    Real-time plan statistic keswxAddNewPlanEntry             0         20       20
    SQL memory manager worka qesmmIRegisterWorkArea:1         0          1        1
    active service list      kswslogon: session logout        0         23       12
    active service list      kswssetsvc: PX session swi       0          6        1
    active service list      kswsite: service iterator        0          1        0
    archive process latch    kcrrgpll                         0          3        3
    cache buffers chains     kcbgtcr_2                        0      1,746      573
    cache buffers chains     kcbgtcr: fast path (cr pin       0      1,024    2,126
    cache buffers chains     kcbgcur_2                        0         60        8
    cache buffers chains     kcbchg1: kslbegin: bufs no       0         16        3
    cache buffers chains     kcbgtcr: fast path               0         14       20
    cache buffers chains     kcbzibmlt: multi-block rea       0         10        0
    cache buffers chains     kcbrls_2                         0          9       53
    cache buffers chains     kcbgtcr: kslbegin shared         0          8        1
    cache buffers chains     kcbrls_1                         0          7       84
    cache buffers chains     kcbgtcr: kslbegin excl           0          6       14
    cache buffers chains     kcbnew: new latch again          0          6        0
    cache buffers chains     kcbzgb: scan from tail. no       0          6        0
    cache buffers chains     kcbzwb                           0          5        8
    cache buffers chains     kcbgcur: fast path (shr)         0          3        0
    cache buffers chains     kcbget: pin buffer               0          3        0
    cache buffers chains     kcbzhngcbk2_1                    0          1        0
    cache buffers lru chain  kcbzgws                          0         19        0
    cache buffers lru chain  kcbo_link_q                      0          3        0
    call allocation          ksuxds                           0         14       10
    call allocation          ksudlp: top call                 0          2        3
    enqueue hash chains      ksqgtl3                          0          2        1
    enqueue hash chains      ksqrcl                           0          1        2
    enqueues                 ksqgel: create enqueue           0          1        0
    object queue header oper kcbo_unlink_q                    0          5        2
    object queue header oper kcbo_sw_buf                      0          2        0
    object queue header oper kcbo_link_q                      0          1        2
    object queue header oper kcbo_switch_cq                   0          1        2
    object queue header oper kcbo_switch_mq_bg                0          1        4
    parallel query alloc buf kxfpbalo                         0          1        1
    process allocation       ksucrp:1                         0          2        0
    process queue reference  kxfpqrsnd                        0          1        0
    qmn task queue latch     kwqmnmvtsks: delay to read       0          1        0
    redo allocation          kcrfw_redo_gen: redo alloc       0         17        0
    row cache objects        kqreqd: reget                    0          6        0
    row cache objects        kqrpre: find obj                 0          6       13
    row cache objects        kqrso                            0          2        0
    row cache objects        kqreqd                           0          1        2
    row cache objects        kqrpre: init complete            0          1        1
    shared pool              kghalo                           0        199      106
    shared pool              kghupr1                          0         39      109
    shared pool              kghfre                           0         18       19
    shared pool              kghalp                           0          7       29
    space background task la ktsj_grab_task                   0         21       27
    Mutex Sleep Summary                
    -> ordered by number of sleeps desc
                                                                             Wait
    Mutex Type            Location                               Sleeps    Time (ms)
    Library Cache         kglhdgn2 106                              338           12
    Library Cache         kgllkc1   57                              259           10
    Library Cache         kgllkdl1  85                              123           21
    Cursor Pin            kkslce [KKSCHLPIN2]                        70          286
    Library Cache         kglget2   2                                31            1
    Library Cache         kglhdgn1  62                               31            2
    Library Cache         kglpin1   4                                26            1
    Library Cache         kglpnal1  90                               18            0
    Library Cache         kglpndl1  95                               15            2
    Library Cache         kgllldl2 112                                6            0
    Library Cache         kglini1   32                                1            0
              -------------------------------------------------------------Thanks in advance.

    Hi,
    Thanks for reply.
    I provided one hour report.
    Inst Num Startup Time    Release     RAC
    1 27-Feb-12 09:03 11.2.0.2.0  NO
      Platform                         CPUs Cores Sockets Memory(GB)
    Linux x86 64-bit                    8     8       8      48.00
                  Snap Id      Snap Time      Sessions Curs/Sess
    Begin Snap:      5606 29-Feb-12 04:00:35        63       3.7
      End Snap:      5607 29-Feb-12 05:00:41        63       3.6
       Elapsed:               60.11 (mins)
       DB Time:              382.67 (mins)
    Cache Sizes                       Begin        End
    ~~~~~~~~~~~                  ---------- ----------
                   Buffer Cache:     1,952M     1,952M  Std Block Size:        16K
               Shared Pool Size:     1,024M     1,024M      Log Buffer:    18,868K
    Load Profile              Per Second    Per Transaction   Per Exec   Per Call
    ~~~~~~~~~~~~         ---------------    --------------- ---------- ----------
          DB Time(s):                6.4                0.8       0.03       0.03
           DB CPU(s):                1.0                0.1       0.00       0.00
           Redo size:           84,539.3           10,425.6
       Logical reads:           23,345.6            2,879.1
       Block changes:              386.5               47.7
      Physical reads:            1,605.0              197.9
    Physical writes:                7.1                0.9
          User calls:              233.9               28.9
              Parses:                4.0                0.5
         Hard parses:                0.1                0.0
    W/A MB processed:                0.1                0.0
              Logons:                0.1                0.0
            Executes:              210.9               26.0
           Rollbacks:                0.0                0.0
        Transactions:                8.1
    Instance Efficiency Percentages (Target 100%)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                Buffer Nowait %:   99.62       Redo NoWait %:  100.00
                Buffer  Hit   %:   95.57    In-memory Sort %:  100.00
                Library Hit   %:   99.90        Soft Parse %:   98.68
             Execute to Parse %:   98.10         Latch Hit %:   99.99
    Parse CPU to Parse Elapsd %:   32.08     % Non-Parse CPU:   99.90
    Shared Pool Statistics        Begin    End
                 Memory Usage %:   89.25   89.45
        % SQL with executions>1:   96.79   97.52
      % Memory for SQL w/exec>1:   95.67   96.56
    Top 5 Timed Foreground Events
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                                               Avg
                                                              wait   % DB
    Event                                 Waits     Time(s)   (ms)   time Wait Class
    db file sequential read           3,054,464      17,002      6   74.0 User I/O
    DB CPU                                            3,748          16.3
    read by other session               199,603         796      4    3.5 User I/O
    direct path read                     46,301         439      9    1.9 User I/O
    db file scattered read               21,113         269     13    1.2 User I/O
    Host CPU (CPUs:    8 Cores:    8 Sockets:    8)
    ~~~~~~~~         Load Average
                   Begin       End     %User   %System      %WIO     %Idle
                    1.45      1.67      13.2       0.6      15.8      86.2
    Instance CPU
    ~~~~~~~~~~~~
                  % of total CPU for Instance:      13.0
                  % of busy  CPU for Instance:      94.7
      %DB time waiting for CPU - Resource Mgr:       0.0
    Memory Statistics
    ~~~~~~~~~~~~~~~~~                       Begin          End
                      Host Mem (MB):     49,152.0     49,152.0
                       SGA use (MB):      3,072.0      3,072.0
                       PGA use (MB):        513.5        467.7
        % Host Mem used for SGA+PGA:         7.29         7.20
    Time Model Statistics            
    -> Total time in database user-calls (DB Time): 22960.5s
    -> Statistics including the word "background" measure background process
       time, and so do not contribute to the DB time statistic
    -> Ordered by % or DB time desc, Statistic name
    Statistic Name                                       Time (s) % of DB Time
    sql execute elapsed time                             22,835.9         99.5
    DB CPU                                                3,748.4         16.3
    parse time elapsed                                       15.4           .1
    hard parse elapsed time                                  14.3           .1
    PL/SQL execution elapsed time                             7.5           .0
    PL/SQL compilation elapsed time                           6.0           .0
    connection management call elapsed time                   1.6           .0
    sequence load elapsed time                                0.4           .0
    hard parse (sharing criteria) elapsed time                0.0           .0
    repeated bind elapsed time                                0.0           .0
    failed parse elapsed time                                 0.0           .0
    DB time                                              22,960.5
    background elapsed time                                 238.1
    background cpu time                                       4.9
    Operating System Statistics        
    -> *TIME statistic values are diffed.
       All others display actual values.  End Value is displayed if different
    -> ordered by statistic type (CPU Use, Virtual Memory, Hardware Config), Name
    Statistic                                  Value        End Value
    BUSY_TIME                                396,506
    IDLE_TIME                              2,483,725
    IOWAIT_TIME                              455,495
    NICE_TIME                                      0
    SYS_TIME                                  16,163
    USER_TIME                                380,052
    LOAD                                           1                2
    RSRC_MGR_CPU_WAIT_TIME                         0
    VM_IN_BYTES                       95,646,943,232
    VM_OUT_BYTES                       1,686,059,008
    PHYSICAL_MEMORY_BYTES             51,539,607,552
    NUM_CPUS                                       8
    NUM_CPU_CORES                                  8
    NUM_CPU_SOCKETS                                8
    GLOBAL_RECEIVE_SIZE_MAX                4,194,304
    GLOBAL_SEND_SIZE_MAX                   1,048,586
    TCP_RECEIVE_SIZE_DEFAULT                  87,380
    TCP_RECEIVE_SIZE_MAX                   4,194,304
    TCP_RECEIVE_SIZE_MIN                       4,096
    TCP_SEND_SIZE_DEFAULT                     16,384
    TCP_SEND_SIZE_MAX                      4,194,304
    TCP_SEND_SIZE_MIN                          4,096
    Operating System Statistics -
    Snap Time           Load    %busy    %user     %sys    %idle  %iowait
    29-Feb 04:00:35      1.4      N/A      N/A      N/A      N/A      N/A
    29-Feb 05:00:41      1.7     13.8     13.2      0.6     86.2     15.8
    Foreground Wait Class              
    -> s  - second, ms - millisecond -    1000th of a second
    -> ordered by wait time desc, waits desc
    -> %Timeouts: value of 0 indicates value was < .5%.  Value of null is truly 0
    -> Captured Time accounts for         97.6%  of Total DB time      22,960.46 (s)
    -> Total FG Wait Time:            18,651.75 (s)  DB CPU time:       3,748.35 (s)
                                                                      Avg
                                          %Time       Total Wait     wait
    Wait Class                      Waits -outs         Time (s)     (ms)  %DB time
    User I/O                    3,327,253     0           18,576        6      80.9
    DB CPU                                                 3,748               16.3
    Commit                         23,882     0               69        3       0.3
    System I/O                      1,035     0                3        3       0.0
    Network                       842,393     0                2        0       0.0
    Other                          10,120    99                0        0       0.0
    Configuration                       3     0                0       58       0.0
    Application                       264     0                0        1       0.0
    Concurrency                     1,482     0                0        0       0.0
    Foreground Wait Events            
    -> s  - second, ms - millisecond -    1000th of a second
    -> Only events with Total Wait Time (s) >= .001 are shown
    -> ordered by wait time desc, waits desc (idle events last)
    -> %Timeouts: value of 0 indicates value was < .5%.  Value of null is truly 0
                                                                 Avg
                                            %Time Total Wait    wait    Waits   % DB
    Event                             Waits -outs   Time (s)    (ms)     /txn   time
    db file sequential read       3,054,464     0     17,002       6    104.5   74.0
    read by other session           199,603     0        796       4      6.8    3.5
    direct path read                 46,301     0        439       9      1.6    1.9
    db file scattered read           21,113     0        269      13      0.7    1.2
    log file sync                    23,882     0         69       3      0.8     .3
    db file parallel read             4,727     0         68      14      0.2     .3
    control file sequential re        1,035     0          3       3      0.0     .0
    SQL*Net message to client       840,792     0          2       0     28.8     .0
    direct path read temp                95     0          2      18      0.0     .0
    local write wait                     79     0          0       4      0.0     .0
    Disk file operations I/O            870     0          0       0      0.0     .0
    ASM file metadata operatio            4     0          0      50      0.0     .0
    log file switch (private s            3     0          0      58      0.0     .0
    ADR block file read                  36     0          0       3      0.0     .0
    enq: RO - fast object reus            5     0          0      16      0.0     .0
    latch: cache buffers chain        1,465     0          0       0      0.1     .0
    SQL*Net break/reset to cli          256     0          0       0      0.0     .0
    asynch descriptor resize         10,059   100          0       0      0.3     .0
    SQL*Net more data to clien        1,510     0          0       0      0.1     .0
    enq: KO - fast object chec            3     0          0       8      0.0     .0
    SQL*Net more data from cli           91     0          0       0      0.0     .0
    latch: shared pool                   14     0          0       0      0.0     .0
    ADR block file write                  5     0          0       1      0.0     .0
    reliable message                      8     0          0       0      0.0     .0
    direct path write temp                1     0          0       2      0.0     .0
    SQL*Net message from clien      840,794     0     68,885      82     28.8
    jobq slave wait                   7,365   100      3,679     499      0.3
    Streams AQ: waiting for me          721   100      3,605    5000      0.0
    wait for unread message on        3,648    98      3,603     988      0.1
    KSV master wait                      20     0          0       0      0.0
    Background Wait Events            
    -> ordered by wait time desc, waits desc (idle events last)
    -> Only events with Total Wait Time (s) >= .001 are shown
    -> %Timeouts: value of 0 indicates value was < .5%.  Value of null is truly 0
                                                                 Avg
                                            %Time Total Wait    wait    Waits   % bg
    Event                             Waits -outs   Time (s)    (ms)     /txn   time
    log file parallel write          29,353     0         83       3      1.0   34.8
    db file parallel write            5,753     0         17       3      0.2    6.9
    db file sequential read           1,638     0         15       9      0.1    6.1
    control file sequential re        5,142     0         13       2      0.2    5.4
    os thread startup                   140     0          8      58      0.0    3.4
    control file parallel writ        1,440     0          8       6      0.0    3.4
    log file sequential read            304     0          8      26      0.0    3.3
    db file scattered read              214     0          2       9      0.0     .8
    ASM file metadata operatio        1,199     0          1       1      0.0     .3
    direct path write                    35     0          0       6      0.0     .1
    direct path read                     41     0          0       5      0.0     .1
    kfk: async disk IO                    6     0          0       9      0.0     .0
    Disk file operations I/O          1,266     0          0       0      0.0     .0
    ADR block file read                  16     0          0       2      0.0     .0
    read by other session                 3     0          0       8      0.0     .0
    Log archive I/O                       2     0          0      10      0.0     .0
    log file sync                         3     0          0       5      0.0     .0
    asynch descriptor resize            341   100          0       0      0.0     .0
    CSS initialization                    1     0          0       6      0.0     .0
    log file single write                 4     0          0       1      0.0     .0
    latch: redo allocation                3     0          0       1      0.0     .0
    ADR block file write                  5     0          0       1      0.0     .0
    LGWR wait for redo copy              45     0          0       0      0.0     .0
    CSS operation: query                  6     0          0       0      0.0     .0
    CSS operation: action                 1     0          0       1      0.0     .0
    SQL*Net message to client           420     0          0       0      0.0     .0
    rdbms ipc message                47,816    39     61,046    1277      1.6
    DIAG idle wait                    7,200   100      7,200    1000      0.2
    Space Manager: slave idle         1,146    98      5,674    4951      0.0
    class slave wait                    284     0      3,983   14026      0.0
    dispatcher timer                     61   100      3,660   60006      0.0
    Streams AQ: qmn coordinato          258    50      3,613   14003      0.0
    Streams AQ: qmn slave idle          130     0      3,613   27789      0.0
    Streams AQ: waiting for ti            7    71      3,608  515430      0.0
    wait for unread message on        3,605   100      3,606    1000      0.1
    pmon timer                        1,201   100      3,604    3001      0.0
    smon timer                           15    73      3,603  240207      0.0
    ASM background timer                754     0      3,602    4777      0.0
    shared server idle wait             120   100      3,601   30006      0.0
    SQL*Net message from clien          554     0          4       7      0.0
    KSV master wait                     101     0          0       2      0.0
    Wait Event Histogram              
    -> Units for Total Waits column: K is 1000, M is 1000000, G is 1000000000
    -> % of Waits: value of .0 indicates value was <.05%; value of null is truly 0
    -> % of Waits: column heading of <=1s is truly <1024ms, >1s is truly >=1024ms
    -> Ordered by Event (idle events last)
                                                        % of Waits
                               Total
    Event                      Waits  <1ms  <2ms  <4ms  <8ms <16ms <32ms  <=1s   >1s
    ADR block file read           52  73.1   1.9   9.6  13.5               1.9
    ADR block file write          10 100.0
    ADR file lock                 12 100.0
    ARCH wait for archivelog l     3 100.0
    ASM file metadata operatio  1203  97.3    .5    .7    .3    .2          .9
    CSS initialization             1                   100.0
    CSS operation: action          1       100.0
    CSS operation: query           6  83.3  16.7
    Disk file operations I/O    2118  95.4   4.5    .1
    LGWR wait for redo copy       45 100.0
    Log archive I/O                2                         100.0
    SQL*Net break/reset to cli   256  99.6    .4
    SQL*Net message to client  839.9 100.0    .0
    SQL*Net more data from cli    91 100.0
    SQL*Net more data to clien  1503 100.0
    asynch descriptor resize   10.4K 100.0
    buffer busy waits              2 100.0
    control file parallel writ  1440   5.7  35.1  24.0  16.3  12.0   5.5   1.5
    control file sequential re  6177  69.4   7.5   5.9   8.1   7.1   1.7    .3
    db file parallel read       4727   1.7   3.2   3.2  10.1  46.6  33.3   1.8
    db file parallel write      5755  42.3  21.3  18.6  11.2   4.6   1.4    .5
    db file scattered read     21.5K   8.4   4.3  11.9  18.9  26.3  25.3   4.9
    db file sequential read    3053.  28.7  15.1  11.1  17.9  21.5   5.4    .3    .0
    direct path read           46.3K   9.9   8.8  18.5  21.7  22.8  15.7   2.7
    direct path read temp         95               9.5   9.5  23.2  49.5   8.4
    direct path write             35  11.4  31.4  17.1  22.9  11.4   2.9   2.9
    direct path write temp         1       100.0
    enq: KO - fast object chec     3                    66.7  33.3
    enq: RO - fast object reus     5  20.0              20.0  20.0  20.0  20.0
    kfk: async disk IO             6  50.0  16.7              16.7        16.7
    latch free                     3 100.0
    latch: cache buffers chain  1465 100.0
    latch: cache buffers lru c     1 100.0
    latch: object queue header     2 100.0
    latch: redo allocation         3  33.3  33.3  33.3
    latch: row cache objects       2 100.0
    latch: shared pool            15  93.3   6.7
    local write wait              79        35.4  34.2  21.5   8.9
    log file parallel write    29.4K  47.8  21.7  11.9   9.9   6.8   1.6    .3
    log file sequential read     304   6.3   3.0   3.6  10.2  23.4  24.3  29.3
    log file single write          4  25.0  75.0
    log file switch (private s     3                                     100.0
    log file sync              23.9K  40.9  28.0  12.9   9.7   6.7   1.5    .3
    os thread startup            140                                     100.0
    read by other session      199.6  37.1  19.9  12.9  13.1  13.8   3.1    .2
    reliable message               8 100.0
    ASM background timer         755   2.9    .4    .1    .1    .3    .1    .3  95.8
    DIAG idle wait              7196                                     100.0
    KSV master wait              121  88.4   2.5   3.3   2.5    .8    .8   1.7
    SQL*Net message from clien 840.1  97.1   1.8    .5    .2    .2    .1    .0    .1
    Space Manager: slave idle   1147    .1                                  .5  99.4
    Streams AQ: qmn coordinato   258  49.6                .4                    50.0
    Streams AQ: qmn slave idle   130    .8                                      99.2
    Streams AQ: waiting for me   721                                           100.0
    Streams AQ: waiting for ti     7  28.6                                42.9  28.6
    class slave wait             283  39.9   2.5   2.5   3.5   4.9   9.2  15.2  22.3
    dispatcher timer              60                                           100.0
    jobq slave wait             7360    .0    .0    .0                    99.9
    pmon timer                  1201                                           100.0
    rdbms ipc message          47.8K   2.7  31.6  17.4   1.1   1.1    .9  20.9  24.3
    Wait Event Histogram               DB/Inst: I2KPROD/I2KPROD  Snaps: 5606-5607
    -> Units for Total Waits column: K is 1000, M is 1000000, G is 1000000000
    -> % of Waits: value of .0 indicates value was <.05%; value of null is truly 0
    -> % of Waits: column heading of <=1s is truly <1024ms, >1s is truly >=1024ms
    -> Ordered by Event (idle events last)
                                                        % of Waits
                               Total
    Event                      Waits  <1ms  <2ms  <4ms  <8ms <16ms <32ms  <=1s   >1s
    shared server idle wait      120                                           100.0
    smon timer                    16                                       6.3  93.8
    wait for unread message on  7250                                  .1  99.9
    Latch Miss Sources                
    -> only latches with sleeps are shown
    -> ordered by name, sleeps desc
                                                         NoWait              Waiter
    Latch Name               Where                       Misses     Sleeps   Sleeps
    In memory undo latch     ktichg: child                    0          1        0
    active service list      kswslogon: session logout        0          2        0
    cache buffers chains     kcbgtcr_2                        0      1,123      483
    cache buffers chains     kcbgtcr: fast path (cr pin       0        496    1,131
    cache buffers chains     kcbrls_2                         0          5        6
    cache buffers chains     kcbgcur_2                        0          4        0
    cache buffers chains     kcbgtcr: fast path               0          3        1
    cache buffers chains     kcbzwb                           0          2        4
    cache buffers chains     kcbchg1: kslbegin: bufs no       0          1        0
    cache buffers chains     kcbnew: new latch again          0          1        0
    cache buffers chains     kcbrls_1                         0          1        6
    cache buffers chains     kcbzgb: scan from tail. no       0          1        0
    cache buffers lru chain  kcbzgws                          0          1        0
    object queue header oper kcbo_switch_cq                   0          1        0
    object queue header oper kcbo_switch_mq_bg                0          1        2
    redo allocation          kcrfw_redo_gen: redo alloc       0          3        0
    row cache objects        kqrpre: find obj                 0          1        1
    row cache objects        kqrso                            0          1        0
    shared pool              kghalo                           0         13        3
    shared pool              kghupr1                          0          4       15
    shared pool              kghalp                           0          1        0
    space background task la ktsj_grab_task                   0          2        2
              -------------------------------------------------------------

  • Issue with "read by other session" and a parallel MERGE query

    Hi everyone,
    we have run into an issue with a batch process updating a large table (12 million rows / a few GB, so it's not that large). The process is quite simple - load the 'increment' from a file into a working table (INCREMENT_TABLE) and apply it to the main table using a MERGE. The increment is rather small (usually less than 10k rows), but the MERGE runs for hours (literally) although the execution plan seems quite reasonable (can post it tomorrow, if needed).
    The first thing we've checked is AWR report, and we've noticed this:
    Top 5 Timed Foreground Events
    Event     Waits     Time(s)     Avg wait (ms)     % DB time     Wait Class
    DB CPU           10,086           43.82     
    read by other session     3,968,673     9,179     2     39.88     User I/O
    db file scattered read     1,058,889     2,307     2     10.02     User I/O
    db file sequential read     408,499     600     1     2.61     User I/O
    direct path read     132,430     459     3     1.99     User I/OSo obviously most of the time was consumed by "read by other session" wait event. There were no other queries running at the server, so in this case "other session" actually means "parallel processes" used to execute the same query. The main table (the one that's updated by the batch process) has "PARALLEL DEGREE 4" so Oracle spawns 4 processes.
    I'm not sure how to fix this. I've read a lot of details about "read by other session" but I'm not sure it's the root cause - in the end, when two processes read the same block, it's quite natural that only one does the physical I/O while the other waits. What really seems suspicious is the number of waits - 4 million waits means 4 million blocks, 8kB each. That's about 32GB - the table has about 4GB, and there are less than 10k rows updated. So 32 GB is a bit overkill (OK, there are indexes etc. but still, that's 8x the size of the table).
    So I'm thinking that the buffer cache is too small - one process reads the data into cache, then it's removed and read again. And again ...
    One of the recommendations I've read was to increase the PCTFREE, to eliminate 'hot blocks' - but wouldn't that make the problem even worse (more blocks to read and keep in the cache)? Or am I completely wrong?
    The database is 11gR2, the buffer cache is about 4GB. The storage is a SAN (but I don't think this is the bottleneck - according to the iostat results it performs much better in case of other batch jobs).

    OK, so a bit more details - we've managed to significantly decrease the estimated cost and runtime. All we had to do was a small change in the SQL - instead of
    MERGE /*+ parallel(D DEFAULT)*/ INTO T_NOTUNIFIED_CLIENT D /*+ append */
      USING (SELECT
          FROM TMP_SODW_BB) S
      ON (D.NCLIENT_KEY = S.NCLIENT_KEY AND D.CURRENT_RECORD = 'Y' AND S.DIFF_FLAG IN ('U', 'D'))
      ...(which is the query listed above) we have done this
    MERGE /*+ parallel(D DEFAULT)*/ INTO T_NOTUNIFIED_CLIENT D /*+ append */
      USING (SELECT
          FROM TMP_SODW_BB AND DIFF_FLAG IN ('U', 'D')) S
      ON (D.NCLIENT_KEY = S.NCLIENT_KEY AND D.CURRENT_RECORD = 'Y')
      ...i.e. we have moved the condition from the MERGE ON clause to the SELECT. And suddenly, the execution plan is this
    OPERATION                           OBJECT_NAME             OPTIONS             COST
    MERGE STATEMENT                                                                 239
      MERGE                             T_NOTUNIFIED_CLIENT
        PX COORDINATOR
          PX SEND                       :TQ10000                QC (RANDOM)         239
            VIEW
              NESTED LOOPS                                      OUTER               239
                PX BLOCK                                        ITERATOR
                  TABLE ACCESS          TMP_SODW_BB             FULL                2
                    Filter Predicates
                      OR
                        DIFF_FLAG='D'
                        DIFF_FLAG='U'
                  TABLE ACCESS          T_NOTUNIFIED_CLIENT       BY INDEX ROWID    3
                    INDEX               AK_UQ_NOTUNIF_T_NOTUNI    RANGE SCAN        2
                      Access Predicates
                        AND
                          D.NCLIENT_KEY(+)=NCLIENT_KEY
                          D.CURRENT_RECORD(+)='Y'
                      Filter Predicates
                        D.CURRENT_RECORD(+)='Y' Yes, I know the queries are not exactly the same - but we can fix that. The point is that the TMP_SODW_BB table contains 1639 rows in total, and 284 of them match the moved 'IN' condition. Even if we remove the condition altogether (i.e. 1639 rows have to be merged), the execution plan does not change (the cost increases to about 1300, which is proportional to the number of rows).
    But with the original IN condition (that turns into an OR combination of predicates) in the MERGE ON clausule, the cost suddenly skyrockets to 990.000 and it's damn slow. It seems like a problem with cost estimation, because once we remove one of the values (so there's only one value in the IN clausule), it works fine again. So I guess it's a planner/estimator issue ...

  • "read by other session" wait

    Hi all,
    I have a query with very little cost, it only access one row of the table from a primary key and joins it another table again on primary key column. It doesn't even take a second to complete.
    But the problem is when there is another session that accesses data from one of the tables, I encounter "read by other session" wait event, so I wonder if there is a hint to overcome this wait, that will force query to make a disk read without waiting any other working session to put it into buffer cache. Or any other suggestions?
    Thanks

    seth2 wrote:
    Hi all,
    I have a query with very little cost, it only access one row of the table from a primary key and joins it another table again on primary key column. It doesn't even take a second to complete.
    You also say in a later post that the cost of the plan is 11 - if this is correct then your two indexes must have a blevel of about 5 to get that cost from that plan. It seems highly likely that your query doesn't always take the plan you expect and that the "10 minute" versions of this query (which should take less than 0.1 seconds on any reasonable system) is doing a large tablescan to spend so much extra time and report "read by other session". I would check v$sql for multiple child cursors and v$sql_plan (using dbms_xplan.display_cursor if you're on 10g) to check executions plans.
    Regards
    Jonathan Lewis
    http://jonathanlewis.wordpress.com
    http://www.jlcomp.demon.co.uk
    To post code, statspack/AWR report, execution plans or trace files, start and end the section with the tag {noformat}{noformat} (lowercase, curly brackets, no spaces) so that the text appears in fixed format.
    "Science is more than a body of knowledge; it is a way of thinking"
    Carl Sagan                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

  • Read by other session wait event

    I have some reports in my database that whenever executed by two or more session these reports suffers with read by other session wait event. Tables which are involving in that's query i moves them to other tablespace and then move back to original tablespace. Some how this could solves read by other session wait event. But after some days these problem occur again.
    How can i permanently solve this problem??
    My db is Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - Prod
    Oracle Block size 4096
    Thanks

    Hi there,
    Searching for this wait eventin the docs gave this,
    http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/waitevents003.htm#sthref3159
    read by other session
    This event occurs when a session requests a buffer that is currently being read into the buffer cache by another session. Prior to release 10.1, waits for this event were grouped with the other reasons for waiting for buffers under the 'buffer busy wait' event
    Wait Time: Time waited for the buffer to be read by the other session (in microseconds)And a quick google search for the same gave these results in the top.
    http://www.confio.com/English/Tips/Read_By_Other_Session.php
    http://www.dbafan.com/blog/?p=132
    HTH
    Aman....

  • Reading Data commited in other session

    Hi
    how can I to read Data commted in other session ?
    Example: in package the process does update and in other session I want to do select and read data from table with data commited , Is possible ?

    Hi,
    Once data is commited you can read it very well by default. Whats wrong with reading commited data by other session?
    Thanks!
    M T

  • How to find out histotry command from other session

    Hi gurus,
    I use RHEL 5.4
    Some user log onto server with root and make change at some files. How can I find out history command from other session with the same user.
    history command is just give me history commands of my own session.
    Thanks
    Ch

    The file which holds the commandline history is .bash_history in the home directory of the user.
    So in the case of root, /root/.bash_history
    Please mind that if you log in as root, or become root your session will add to that file as well.
    Another issue with the history file is that when multiple sessions are logged in, every session writes in its own version of the same file. So the last one "wins", which means that version is the one which is truly stored.
    If files are changed, a find command with the 'mtime' parameter should be helpful.

  • Tables stored in memory but may be accessed from other sessions

    Dear Oracle experts,
    it may be a stupid question but I'm searching for the best possibility to create a kind of temporary table which may be accessed from other sessions.
    Could you provide some hints/ catchwords to speed up my recherches.
    Thank you very much,
    Daniel

    danielwetzler wrote:
    danielwetzler wrote:
    I fear that the caching is not suitable for my case because of the reasons decribed in my other postings...First of all I don't think that you need to worry about the effectiveness of the caching in your particular case. In addition Oracle is very clever at when to actually write the dirty blocks from the buffer cache to the disks, so if your amount of data written to the result table is fairly small and no other activity is going on your system it won't get written to disk immediately anyway but stay in memory until any of the conditions are met that trigger the database writer to flush the blocks to disk.
    But there are options you could consider if you want to avoid as much of the overhead as possible and to write the results of your calculation to the result table as fast as possible.
    You could use direct-path inserts (INSERT /*+ APPEND */) and set the result table to "NOLOGGING". This way no undo and minimum redo is generated.
    Note however that there are certain caveats and restrictions to consider when using such an approach, e.g. your result table won't be recoverable (which you say is OK), only one direct-path insert is allowed simultaneously (it blocks the table exclusively, no other DML possible until you commit/rollback the transaction), and the direct-path insert has some restrictions. If any of these apply that prevent the direct-path operation then it silently falls back to "conventional" insert mode which generates undo and redo. One of the more annoying restrictions is that you can't read from a table that has been written to in direct-path mode within the same transaction, you first have to commit the transaction, otherwise you get "ORA-12838: cannot read/modify an object after modifying it in parallel". This means by simply adding the APPEND hint you might break existing logic.
    Finally the direct-path insert never re-uses free space in blocks below the current high-water mark, which means if you perform a direct-path insert and afterwards delete rows from the table and repeat again a direct-path insert operation your segment will grow and the empty space in the already used blocks won't get re-used. Best way would be to truncate the table rather than deleting rows from it.
    There are workarounds available to overcome some of these direct-path insert limitations (exclusive lock, truncate instead of delete etc.), like using a partitioned table (if you have a suitable edition/license), because direct-path inserts can be restricted to partitions. In this case you can do simultaneous direct-path inserts if you use different partitions, but you need then some kind of logic that determines which partition to use.
    Regards,
    Randolf
    Oracle related stuff blog:
    http://oracle-randolf.blogspot.com/
    SQLTools++ for Oracle (Open source Oracle GUI for Windows):
    http://www.sqltools-plusplus.org:7676/
    http://sourceforge.net/projects/sqlt-pp/

  • In private browsing not working in Firefox 3.6.12 If I open yahoomail one session for one account and if I open other session for yahoomail, it automatically opens the earlier mail account.

    In private browsing not working in Firefox 3.6.12 If I open yahoomail one session for one account and if I open other session for yahoomail, it automatically opens the earlier mail account. But if I want to use more than one yahoomail accounts, in private browsing is not working. Please suggest.

    That problem isn't related to Private Browsing specifically, that's how Firefox works with regards to multiple "sessions" with the same server - only one logon is allowed at any time. Try using one of these extensions to be able to run multiple session cookies.
    Multifox: <br />
    http://br.mozdev.org/multifox/ <br />
    Cookie Swap extension: <br />
    https://addons.mozilla.org/firefox/3255/ <br />
    Cookie Pie extension: <br />
    http://www.nektra.com/oss/firefox/extensions/cookiepie/

  • Trace other session in 9.2.0.6

    Hi,
    I'm mostly using oradebug for setting 10046 trace event in other session .
    This works without problems , until I hit old 9.2.0.6 DB on WINDOWS 2000 .
    Every time I'm using that approach
    ORADEBUG SETOSPID &OSPID ;
    ORADEBUG EVENT 10046 TRACE NAME CONTEXT FOREVER, LEVEL 12;
    ORADEBUG TRACEFILE_NAME;
    Traced process gives:
    ORA-03113: end-of-file on communication channelI've tried exec dbms_system.set_ev(10,20,10046,12,''); with no success as well (same error) .
    How You deal with that kind of old software on Windows 2000 ?
    Please advice with real life experience I've read doc :).
    Regards
    GregG

    Thanks , looks like that worked .
    I did some additional tests and here follows my thoughts:
    1. All mentioned methods works (oradebug, dbms_system.set_ev) if traced session is not in tight pl/sql loop like:
    declare
    l_c number;
    begin
    for i in 1 .. 1000
    loop
    select count(*) into l_c from dba_source;
    end loop;
    end;
    /Session which is doing so crashed in all cased with exception of usage dbms_support .
    So, thanks again.
    Regards
    GregG

  • I have Elements 10 and every time I go to open a file in the editor it shows its thinking and then it just shuts down the entire program. I have a big wedding I am working on and lots of other sessions. Please PLEASE help!!!!

    I have Elements 10 and every time I go to open a file in the editor it shows its thinking and then it just shuts down the entire program. I have a big wedding I am working on and lots of other sessions. Please PLEASE help!!!!

    And you are quite persistent, Menu Boy, in offering pernickety and pointless prattle, in response to a "support page" on iPad's buggy Pages App.
    Let's summarise, for those reviewing this threadless thread for app support..
    Mobile pages works reliably for simple docs, especially creating letters and Menus for Microsoft's Kindy canteen (even on special days with nice big pictures).
    When importing more complex docs and/or working with larger creations, it is prone to randomly corrupting files upon re-opening, along similar lines as Word (running on a PC).
    So, Menu Boy, do they let you sneak into classes every now and then? What is the secret to their training? "Say after me, if any I.T. product works just some of the time, that's a job well done, and if something randomly stops working, we call that the user's fault... And if they complain, we call them names."

  • How to view uncommited data from other session

    Hi
    I want to see data that is incommited from other sql session. How can I see it?
    Generally After commit data is available to other sessions.
    Please answer me ASAP.
    Wating for reply
    Jigar,

    You cannot do 'dirty reads' in Oracle. You can only see committed changes, and you have the choice of seeing committed changes after each individual statement in your transaction (default), or only after a transaction has finished. With the default level, running the same query multiple times within a transaction may yield different results.
    I suspect that you have used this approach with Sybase or SQL Server for performance reasons, but you will not need to do this with Oracle. I recommend you read Tom Kyte's "Expert One-On-One: Oracle" book for an excellent discussion of Oracle's locking and concurrency mechanisms.
    Hi
    I want to see data that is incommited from other sql session. How can I see it?
    Generally After commit data is available to other sessions.
    Please answer me ASAP.
    Wating for reply
    Jigar,

  • DBA commit other session's transaction?

    Hi, everyone,
    A quick question, can a DBA commit {color:#0000ff}other session's transaction{color}?
    If so, how?
    Thanks!
    Alex

    Transactions can be as long as what the user logic demands. There is no transactions that is too long or too large. Oracle doesn't break, slowdown, or underperform because of long or big transactions. If you look deep into how oracle handles transactions in the background, you'll see why.
    It's interesting you mentioned that. I hope you really looked deep into how oracle handles transactions so you can en-light us how long and large transaction not affecting performance.
    perhaps we should start with Oracle Concept shall we?
    http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/transact.htm#CNCPT117
    In a nutshell long and large transaction has potential performance impact at least in these aspects.
    A transaction will generate undo information, until the transaction is committed, these undo segment can't be reused. As transaction grows the undo space held hostage grows. Potential performance impact No.1
    A transaction usually hold locks on rows you made changes. until your transaction is committed, no other user can update these rows and need to wait for the lock. Potential performance impact No.2
    The third one is situation like yours, when a session held long and big transaction dropped, Oracle need to rollback all the changes made to database. Some of these changes already been flushed to disk (especially since it's long and large transaction). In that case, Oracle will need to load all changed data blocks and apply undo information back.
    On the other hand, since you are seeking ways for DBA to commit the uncommit change you made recklessly, that means you could have committed the changes. There's certainly no user logic to hold these changes as one single transaction.

  • When I try to use ExportPDF, a box shows up that reads "retrieving current session status"

    When I try to use ExportPDF, a box shows up that reads "retrieving current session status" and I am unable to continue.

    Hi Kyle,
    Could you try:
      Choose Edit > Preferences (Win) or Adobe Reader > Preferences (Mac)
      Click 'Online Services' on the left-hand side
      Sign out of our Adobe ID and sign back in.
      Try to convert your document again.
    Let us know how it goes.
    -David

  • How to delete a Analytic Workspace even other session still attached it

    how to delete a Analytic Workspace even other session still attached that Analytic Workspace?
    or how to detach the Analytic Workspace with other session?
    or how to find session which connected to the Analytic Workspace?
    Thanks

    Here are the sql queries which will tell you who is attached to which aw in which mode.
    select username, sid, serial#, owner||'.'||daws.aw_name aw,
    decode(attach_mode, 'READ WRITE', 'RW',
    'READ ONLY', 'RO', attach_mode) attch,
    trunc(pool_size/1024)||' KB' as curr_opp_kb
    from dba_aws daws, gv$aw_olap gvawo , gv$aw_calc gvawc, gv$session
    where daws.aw_number = gvawo.aw_number and
    sid = gvawo.session_id and gvawc.session_id=sid
    order by owner, sid, daws.aw_name;
    select a.owner,a.aw_name,b.attach_mode
    from dba_aws a ,v$aw_olap b
    where a.aw_number = b.aw_number;
    You might have to kill the RO session before deleting the AW.
    Thanks
    Brijesh

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