Physical reads in Database

Dear Experts,
I need to pull distinct SQL IDs for the SQLs run by a particular user - "PROD" b/w 9am - 5pm ( snap IDs 1000 - 1008). I wrote below SQL:
select distinct sql_id from DBA_HIST_SQLSTAT where PARSING_SCHEMA_NAME = 'PROD' and snap_id between 1000 and 1008
Does anyone see a reason why this can be wrong?
Thanks for sharing inputs.

Ora DBA wrote:
Dear Experts,
I need to pull distinct SQL IDs for the SQLs run by a particular user - "PROD" b/w 9am - 5pm ( snap IDs 1000 - 1008). I wrote below SQL:
select distinct sql_id from DBA_HIST_SQLSTAT where PARSING_SCHEMA_NAME = 'PROD' and snap_id between 1000 and 1008
Does anyone see a reason why this can be wrong?
Thanks for sharing inputs.SQL statements are NOT associated with any particular USER; which is why they reside in the SHARED Global Area.

Similar Messages

  • Logical read Vs Physical Reads

    Hi,
    I want to know How should we balance the logical reads and physical reads on database.
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    objects it will cause latch contention.
    If it is physical read then it will take more time to read from disk than reading from SGA.
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    Physical reads: 1,095.91 15.38
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    amitbansode wrote:
    I want to know How should we balance the logical reads and physical reads on database.There is no balance as it implies some kind of "+perfect ratio+" for logical I/O vs. physical I/O.
    A high percentage of physical I/O can be perfectly acceptable and normal and correct for a specific database (e.g. think of a system collecting telemetry data where 90% or more of all I/O is writing new telemetry into the database and the remaining 10% is querying the data, with old data being aged out from the database using partition drops which is negligible I/O).
    A high percentage of logical I/O can be indicative of a serious application design problem - where 80GB of database data is read and read again and again and again.. resulting in over a TB of logical I/O. (actually saw this in production database some years ago)
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    And I want to emphasise what Mark said - tuning requires you to identify the performance problem first, before trying to solve it.
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  • Can we run application services when physical stand by database is in read

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  • What causes BUFFER GETS and PHYSICAL READS in INSERT operation to be high?

    Hi All,
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    Flake wrote:
    Hans, gracias.
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  • Query on data dictionary results in large number of physical reads

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    Parse        1      0.01       0.01          0          0          0           0
    Execute      1     31.70      47.57      88570         22          0           1
    Fetch        0      0.00       0.00          0          0          0           0
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    Misses in library cache during parse: 1
    Optimizer mode: CHOOSE
    Parsing user id: 22 
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      ----------------------------------------   Waited  ----------  ------------
      latch: row cache objects                        1        0.00          0.00
      log file sync                                   1        0.00          0.00
      SQL*Net message to client                       1        0.00          0.00
      SQL*Net message from client                     1        0.00          0.00
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  • High no. of physical reads of a query in statspack report

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    PLAN_TABLE_OUTPUT
    | Id  | Operation              |  Name            | Rows  | Bytes |TempSpc| Cost
      |
    |   0 | SELECT STATEMENT       |                  |  2870 |   762K|       |  202
    PLAN_TABLE_OUTPUT
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    |   1 |  SORT ORDER BY         |                  |  2870 |   762K|  1592K|  202
    8 |
    |   2 |   NESTED LOOPS OUTER   |                  |  2870 |   762K|       |  190
    2 |
    |   3 |    NESTED LOOPS OUTER  |                  |  2870 |   714K|       |  190
    2 |
    PLAN_TABLE_OUTPUT
    |   4 |     HASH JOIN OUTER    |                  |  2870 |   667K|       |  190
    2 |
    |   5 |      HASH JOIN OUTER   |                  |  2870 |   616K|       |  189
    2 |
    |   6 |       TABLE ACCESS FULL| OM_MEM_REG_HEAD  |  2870 |   566K|       |  188
    2 |
    |   7 |       TABLE ACCESS FULL| OM_COUNTRY       |   677 | 12186 |       |
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    |   8 |      TABLE ACCESS FULL | OM_COUNTRY       |   677 | 12186 |       |
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    |  10 |    INDEX UNIQUE SCAN   | CITY_CODE_PK     |     1 |    17 |       |
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    Edited by: user00726 on Feb 3, 2009 5:03 AM

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  • Oracle 9i Performance Issue High Physical Reads

    Dear All,
    I have Oracle 9i Release 9.2.0.5.0 database under HP Unix, I have run the query and got following output. Can any body just have a look and advise what to do in the following situation? We have performance issues.
    Many thanks in advance
    Buffer Pool Advisory for DB: DBPR Instance: DBPR End Snap: 902
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    Size for Size Buffers for Est Physical Estimated
    P Estimate (M) Factr Estimate Read Factor Physical Reads
    D 416 .1 51,610 4.27 1,185,670,652
    D 832 .2 103,220 2.97 825,437,374
    D 1,248 .3 154,830 2.03 563,139,985
    D 1,664 .4 206,440 1.49 412,550,232
    D 2,080 .5 258,050 1.32 366,745,510
    D 2,496 .6 309,660 1.23 340,820,773
    D 2,912 .7 361,270 1.14 317,544,771
    D 3,328 .8 412,880 1.09 301,680,173
    D 3,744 .9 464,490 1.04 288,191,418
    D 4,096 1.0 508,160 1.00 276,929,627

    Hi,
    Actually you didnt give the exact problem statement.
    Seems to be your database is I/O bound. Ok, do the following one by one:
    1. Identify the FTS queries and try to create the optimal indexes (depending on the disk reads factor!!) on the problem queries.
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  • Physical reads

    I 'm running the same query against two databases on two different servers, and not seeing the expected results.
    Query runs in 6 seconds on server A, and 32 seconds on server B. The database on B is a copy of the database on A, same blocksize, same db_file_multiblock_read_count.
    Query is:
    SELECT
    IMS_BO_PMAN08.REF_ID,( sum(IMS_BO_PMAN08_TRAN.MONTH_13_APR) ) + ( sum(IMS_BO_PMAN08_TRAN.MONTH_14_MAY) ) ,
    decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,'A','Actual','F','Forecast'),
    decode(IMS_BO_PMAN08_TRAN.TRANS_TYPE,'E','Expenditure','U','Unit completions','A','Allocation Takeup','S','SOS units','T','SOS Expenditure','G','Grant Claim Units','H','Larger Homes','C','FC Unit Completions','F','FC Expenditure','V','ACQ Expenditure')
    FROM
    IMS_BO_PMAN08,
    IMS_BO_PMAN08_TRAN
    WHERE
    ( IMS_BO_PMAN08.PROG_MAN_ID=IMS_BO_PMAN08_TRAN.PROG_MAN_ID )
    AND ( IMS_BO_PMAN08.VERSION_ID IN (select version_id from ims_bo_version where version_id = 1 ) )
    AND ( IMS_BO_PMAN08.INV_REGION_CODE > 2 )
    and decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,'A','Actual','F','Forecast') ='Actual'
    GROUP BY
    IMS_BO_PMAN08.REF_ID,decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,'A','Actual','F','Forecast'),
    decode(IMS_BO_PMAN08_TRAN.TRANS_TYPE,'E','Expenditure','U','Unit completions','A','Allocation Takeup','S','SOS units','T','SOS Expenditure','G','Grant Claim Units','H','Larger Homes','C','FC Unit Completions','F','FC Expenditure','V','ACQ Expenditure');
    I am seeing the same execution plan when running the query against either database, with the same cost in each case. However, the physical reads on server B is ten times that of on server A
    Server A
    =====
    293851 rows selected.
    Elapsed: 00:00:06.58
    Execution Plan
    0 SELECT STATEMENT Optimizer=FIRST_ROWS (Cost=50270 Card=27811 Bytes=973385)
    1 0 SORT (GROUP BY) (Cost=50270 Card=27811 Bytes=973385)
    2 1 HASH JOIN (Cost=50088 Card=27811 Bytes=973385)
    3 2 TABLE ACCESS (BY INDEX ROWID) OF 'IMS_BO_PMAN08' (Cost=17990 Card=26243 Bytes=446131)
    4 3 INDEX (RANGE SCAN) OF 'IMS_BO_PMAN08_IX1' (UNIQUE) (Cost=105 Card=26243)
    5 2 NESTED LOOPS (Cost=32049 Card=107258 Bytes=1930644)
    6 5 INDEX (UNIQUE SCAN) OF 'IMS_BO_VERSION_IX1' (UNIQUE)
    7 5 TABLE ACCESS (FULL) OF 'IMS_BO_PMAN08_TRAN' (Cost=32048 Card=107258 Bytes=1716128)
    Statistics
    0 recursive calls
    13 db block gets
    288529 consistent gets
    *18,218 physical reads*
    0 redo size
    17924295 bytes sent via SQL*Net to client
    2174914 bytes received via SQL*Net from client
    19592 SQL*Net roundtrips to/from client
    0 sorts (memory)
    1 sorts (disk)
    293851 rows processed
    Server B
    =====
    292677 rows selected.
    Elapsed: 00:00:32.66
    Execution Plan
    0 SELECT STATEMENT Optimizer=FIRST_ROWS (Cost=50255 Card=27805 Bytes=973175)
    1 0 SORT (GROUP BY) (Cost=50255 Card=27805 Bytes=973175)
    2 1 HASH JOIN (Cost=50073 Card=27805 Bytes=973175)
    3 2 TABLE ACCESS (BY INDEX ROWID) OF 'IMS_BO_PMAN08' (Cost=17984 Card=26237 Bytes=446029)
    4 3 INDEX (RANGE SCAN) OF 'IMS_BO_PMAN08_IX1' (UNIQUE) (Cost=105 Card=26237)
    5 2 NESTED LOOPS (Cost=32040 Card=107230 Bytes=1930140)
    6 5 INDEX (UNIQUE SCAN) OF 'IMS_BO_VERSION_IX1' (UNIQUE)
    7 5 TABLE ACCESS (FULL) OF 'IMS_BO_PMAN08_TRAN' (Cost=32039 Card=107230 Bytes=1715680)
    Statistics
    0 recursive calls
    357 db block gets
    250918 consistent gets
    *188,332 physical reads*
    0 redo size
    17853447 bytes sent via SQL*Net to client
    2166145 bytes received via SQL*Net from client
    19513 SQL*Net roundtrips to/from client
    0 sorts (memory)
    1 sorts (disk)
    292677 rows processed
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    Can anyone tell me where the excessive physical i/o's (and presumably associated runtime) is coming from? Any pointers much appreciated.
    Pete
    Edited by: user12248598 on 17-Mar-2010 09:01

    sort_area_size, sort_area_retained_size & hash_area_size are the same size for both instances, as are all NLS settings.
    Tables are not specified NOCACHE, and there are no additional buffer pools.
    Running with sql_trace enabled for both queries highlighed some very interesting results:
    For the slow query, this is the tkprof output, unfortunately waits=yes is not available in 8.1.6
    TKPROF: Release 8.1.6.3.0 - Production on Tue Mar 23 14:54:18 2010
    (c) Copyright 1999 Oracle Corporation.  All rights reserved.
    Trace file: imsroc_ora_10166.trc
    Sort options: default
    count    = number of times OCI procedure was executed
    cpu      = cpu time in seconds executing
    elapsed  = elapsed time in seconds executing
    disk     = number of physical reads of buffers from disk
    query    = number of buffers gotten for consistent read
    current  = number of buffers gotten in current mode (usually for update)
    rows     = number of rows processed by the fetch or execute call
    alter session set events '10046 trace name context forever, level 8'
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        0      0.00       0.00          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        1      0.00       0.00          0          0          0           0
    Misses in library cache during parse: 0
    Misses in library cache during execute: 1
    Optimizer goal: FIRST_ROWS
    Parsing user id: 5
    BEGIN DBMS_APPLICATION_INFO.SET_MODULE(:1,NULL); END;
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        1      0.00       0.00          0          0          0           0
    Execute      1      0.01       0.01          0          0          0           1
    Fetch        0      0.00       0.00          0          0          0           0
    total        2      0.01       0.01          0          0          0           1
    Misses in library cache during parse: 1
    Optimizer goal: FIRST_ROWS
    Parsing user id: 5
    SELECT
      IMS_BO_PMAN08.REF_ID,
       ( sum(IMS_BO_PMAN08_TRAN.MONTH_13_APR) ) + ( sum(IMS_BO_PMAN08_TRAN.MONTH_14_MAY) ) ,
         decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,'A','Actual','F','Forecast'),
      decode(IMS_BO_PMAN08_TRAN.TRANS_TYPE,'E','Expenditure','U','Unit completions','A','Allocation Takeup
    ','S','SOS units','T','SOS Expenditure','G','Grant Claim Units','H','Larger Homes','C','FC Unit Comple
    tions','F','FC Expenditure','V','ACQ Expenditure')
    FROM
      bo_ims.IMS_BO_PMAN08,
      bo_ims.IMS_BO_PMAN08_TRAN
    WHERE  ( IMS_BO_PMAN08.PROG_MAN_ID=IMS_BO_PMAN08_TRAN.PROG_MAN_ID  )
      AND  ( IMS_BO_PMAN08.VERSION_ID IN (select  version_id from bo_ims.ims_bo_version where version_id =
    1 ) )
        AND  ( IMS_BO_PMAN08.INV_REGION_CODE > 2  )
        and decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,'A','Actual','F','Forecast') = 'Actual'
    GROUP BY
      IMS_BO_PMAN08.REF_ID,
        decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,'A','Actual','F','Forecast'),
      decode(IMS_BO_PMAN08_TRAN.TRANS_TYPE,'E','Expenditure','U','Unit completions','A','Allocation Takeup
    ','S','SOS units','T','SOS Expenditure','G','Grant Claim Units','H','Larger Homes','C','FC Unit Comple
    tions','F','FC Expenditure','V','ACQ Expenditure')
    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    16278     15.36      36.39     215625     251560        361      244156
    total    16280     15.36      36.39     215625     251560        361      244156
    Misses in library cache during parse: 0
    Optimizer goal: FIRST_ROWS
    Parsing user id: 5
    OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        2      0.00       0.00          0          0          0           0
    Execute      3      0.01       0.01          0          0          0           1
    Fetch    16278     15.36      36.39     215625     251560        361      244156
    total    16283     15.37      36.40     215625     251560        361      244157
    Misses in library cache during parse: 1
    Misses in library cache during execute: 1
    OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        0      0.00       0.00          0          0          0           0
    Execute      0      0.00       0.00          0          0          0           0
    Fetch        0      0.00       0.00          0          0          0           0
    total        0      0.00       0.00          0          0          0           0
    Misses in library cache during parse: 0
        3  user  SQL statements in session.
        0  internal SQL statements in session.
        3  SQL statements in session.
    Trace file: imsroc_ora_10166.trc
    Trace file compatibility: 8.00.04
    Sort options: default
           2  sessions in tracefile.
           5  user  SQL statements in trace file.
           0  internal SQL statements in trace file.
           3  SQL statements in trace file.
           3  unique SQL statements in trace file.
       75998  lines in trace file.And this is the tkprof formatted output for the faster running query:
    TKPROF: Release 8.1.6.3.0 - Production on Tue Mar 23 14:56:28 2010
    (c) Copyright 1999 Oracle Corporation.  All rights reserved.
    Trace file: imslive_ora_7489.trc
    Sort options: default
    count    = number of times OCI procedure was executed
    cpu      = cpu time in seconds executing
    elapsed  = elapsed time in seconds executing
    disk     = number of physical reads of buffers from disk
    query    = number of buffers gotten for consistent read
    current  = number of buffers gotten in current mode (usually for update)
    rows     = number of rows processed by the fetch or execute call
    alter session set events '10046 trace name context forever, level 8'
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        0      0.00       0.00          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        1      0.00       0.00          0          0          0           0
    Misses in library cache during parse: 0
    Misses in library cache during execute: 1
    Optimizer goal: FIRST_ROWS
    Parsing user id: 5
    SELECT
      IMS_BO_PMAN08.REF_ID,
       ( sum(IMS_BO_PMAN08_TRAN.MONTH_13_APR) ) + ( sum(IMS_BO_PMAN08_TRAN.MONTH_14_MAY) ) ,
         decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,:SYS_B_00,:SYS_B_01,:SYS_B_02,:SYS_B_03),
      decode(IMS_BO_PMAN08_TRAN.TRANS_TYPE,:SYS_B_04,:SYS_B_05,:SYS_B_06,:SYS_B_07,:SYS_B_08,:SYS_B_09,:SYS_B_10,:
    SYS_B_11,:SYS_B_12,:SYS_B_13,:SYS_B_14,:SYS_B_15,:SYS_B_16,:SYS_B_17,:SYS_B_18,:SYS_B_19,:SYS_B_20,:SYS_B_21,:
    SYS_B_22,:SYS_B_23)
    FROM
      BO_IMS.IMS_BO_PMAN08,
      BO_IMS.IMS_BO_PMAN08_TRAN
    WHERE  ( IMS_BO_PMAN08.PROG_MAN_ID=IMS_BO_PMAN08_TRAN.PROG_MAN_ID  )
      AND  ( IMS_BO_PMAN08.VERSION_ID IN (select  version_id from bo_ims.ims_bo_version where version_id = :SYS_B_
    24 ) )
        AND  ( IMS_BO_PMAN08.INV_REGION_CODE > :SYS_B_25  )
        and decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,:SYS_B_26,:SYS_B_27,:SYS_B_28,:SYS_B_29) = :SYS_B_30
    GROUP BY
      IMS_BO_PMAN08.REF_ID,
        decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,:SYS_B_31,:SYS_B_32,:SYS_B_33,:SYS_B_34),
      decode(IMS_BO_PMAN08_TRAN.TRANS_TYPE,:SYS_B_35,:SYS_B_36,:SYS_B_37,:SYS_B_38,:SYS_B_39,:SYS_B_40,:SYS_B_41,:
    SYS_B_42,:SYS_B_43,:SYS_B_44,:SYS_B_45,:SYS_B_46,:SYS_B_47,:SYS_B_48,:SYS_B_49,:SYS_B_50,:SYS_B_51,:SYS_B_52,:
    SYS_B_53,:SYS_B_54)
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        1      0.00       0.00          0          0          0           0
    Execute      2      0.00       0.00          0          0          0           0
    Fetch    20042      0.00       0.00      20064     295221         13      300608
    total    20045      0.00       0.00      20064     295221         13      300608
    Misses in library cache during parse: 1
    Optimizer goal: FIRST_ROWS
    Parsing user id: 5
    Rows     Row Source Operation
    300608  SORT GROUP BY
    300628   NESTED LOOPS
      55647    NESTED LOOPS
          2     INDEX UNIQUE SCAN (object id 151050)
      55647     TABLE ACCESS BY INDEX ROWID IMS_BO_PMAN08
      55649      INDEX RANGE SCAN (object id 185149)
    300628    TABLE ACCESS BY INDEX ROWID IMS_BO_PMAN08_TRAN
    356274     INDEX RANGE SCAN (object id 157241)
    DELETE FROM PLAN_TABLE
    WHERE
    STATEMENT_ID=:1
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        1      0.00       0.00          0          0          0           0
    Execute      1      0.00       0.00          3          5         12           0
    Fetch        0      0.00       0.00          0          0          0           0
    total        2      0.00       0.00          3          5         12           0
    Misses in library cache during parse: 1
    Optimizer goal: FIRST_ROWS
    Parsing user id: 5
    Rows     Row Source Operation
          1  DELETE PLAN_TABLE
          1   TABLE ACCESS FULL PLAN_TABLE
    EXPLAIN PLAN SET STATEMENT_ID='PLUS18028884' FOR SELECT
      IMS_BO_PMAN08.REF_ID,
       ( sum(IMS_BO_PMAN08_TRAN.MONTH_13_APR) ) + ( sum(IMS_BO_PMAN08_TRAN.MONTH_14_MAY) ) ,
         decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,'A','Actual','F','Forecast'),
      decode(IMS_BO_PMAN08_TRAN.TRANS_TYPE,'E','Expenditure','U','Unit completions','A','Allocation Takeup','S','S
    OS units','T','SOS Expenditure','G','Grant Claim Units','H','Larger Homes','C','FC Unit Completions','F','FC E
    xpenditure','V','ACQ Expenditure')
    FROM
      BO_IMS.IMS_BO_PMAN08,
      BO_IMS.IMS_BO_PMAN08_TRAN
    WHERE  ( IMS_BO_PMAN08.PROG_MAN_ID=IMS_BO_PMAN08_TRAN.PROG_MAN_ID  )
      AND  ( IMS_BO_PMAN08.VERSION_ID IN (select  version_id from bo_ims.ims_bo_version where version_id = 1 ) )
        AND  ( IMS_BO_PMAN08.INV_REGION_CODE > 2  )
        and decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,'A','Actual','F','Forecast') = 'Actual'
    GROUP BY
      IMS_BO_PMAN08.REF_ID,
        decode(IMS_BO_PMAN08_TRAN.TRANS_SUB_TYPE,'A','Actual','F','Forecast'),
      decode(IMS_BO_PMAN08_TRAN.TRANS_TYPE,'E','Expenditure','U','Unit completions','A','Allocation Takeup','S','S
    OS units','T','SOS Expenditure','G','Grant Claim Units','H','Larger Homes','C','FC Unit Completions','F','FC E
    xpenditure','V','ACQ Expenditure')
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        1      0.00       0.00          0          0          0           0
    Execute      0      0.00       0.00          0          0          0           0
    Fetch        0      0.00       0.00          0          0          0           0
    total        1      0.00       0.00          0          0          0           0
    Misses in library cache during parse: 1
    Optimizer goal: FIRST_ROWS
    Parsing user id: 5
    insert into plan_table (statement_id, timestamp, operation, options,
      object_node, object_owner, object_name, object_instance, object_type,
      search_columns, id, parent_id, position, other,optimizer, cost, cardinality,
       bytes, other_tag, partition_start, partition_stop, partition_id,
      distribution )
    values
    (:1,SYSDATE,:2,:3,:4,:5,:6,:7,:8,:9,:10,:11,:12,:13,:14,:15,:16,:17,:18,:19,
      :20,:21,:22)
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        1      0.00       0.00          0          0          0           0
    Execute      7      0.00       0.00          1          3          9           7
    Fetch        0      0.00       0.00          0          0          0           0
    total        8      0.00       0.00          1          3          9           7
    Misses in library cache during parse: 1
    Optimizer goal: FIRST_ROWS
    Parsing user id: 5     (recursive depth: 1)
    select o.name, u.name
    from
    sys.obj$ o, sys.user$ u where obj# = :1and owner# = user#
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        1      0.00       0.00          0          0          0           0
    Execute      2      0.00       0.00          0          0          0           0
    Fetch        2      0.00       0.00          3         12          0           2
    total        5      0.00       0.00          3         12          0           2
    Misses in library cache during parse: 1
    Optimizer goal: CHOOSE
    Parsing user id: SYS   (recursive depth: 1)
    OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        3      0.00       0.00          0          0          0           0
    Execute      4      0.00       0.00          3          5         12           0
    Fetch    20042      0.00       0.00      20064     295221         13      300608
    total    20049      0.00       0.00      20067     295226         25      300608
    Misses in library cache during parse: 3
    Misses in library cache during execute: 1
    OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        2      0.00       0.00          0          0          0           0
    Execute      9      0.00       0.00          1          3          9           7
    Fetch        2      0.00       0.00          3         12          0           2
    total       13      0.00       0.00          4         15          9           9
    Misses in library cache during parse: 2
        5  user  SQL statements in session.
        1  internal SQL statements in session.
        6  SQL statements in session.
    Trace file: imslive_ora_7489.trc
    Trace file compatibility: 8.00.04
    Sort options: default
           3  sessions in tracefile.
           8  user  SQL statements in trace file.
           1  internal SQL statements in trace file.
           6  SQL statements in trace file.
           6  unique SQL statements in trace file.
       77410  lines in trace file.The sql statement as run did not make use of bind variables, so the ones in the tkprof output for the longer running statement made me immediately think of cursor sharing, and right there in the init.ora for the faster running database was CURSOR_SHARING=FORCE.
    I'm not familiar with the history of the databases, nor the specific reasoning for enabling cursor sharing (bind variable usage seems prevalent in all custom code) so I've replicated the setting on the slower database, resulting in a similar tkprof output to the faster server, with a runtime of 7 seconds for 2nd and subsequent runs.
    My immediate issue is now solved, thanks to all who contributed, and apologies for not spotting the obvious earlier.
    Regards, Pete

  • No of physical reads of buffers from disk on PROD and Clone has huge differ

    Please help !
    I am having a problem interpreting a tkprof report.
    I am executing the same statement below in PROD and Clone of PROD.
    What I do not understand why the tkprof report shows huge difference in disk reads for same executions from PROD and Clone of PROD. I.e. first execution disk reads = 757187 , second = 6.
    I expected to see Similar disk reads in the second execution also.The data it fetches is same in both the Instances.
    Statment
    SELECT NVL(SUM(RG_OTH.DEBIT),0),NVL(SUM(RG_OTH.CREDIT),0)
    FROM
    JA_IN_PLA PLA,JAI_RG_OTHERS RG_OTH,HR_ALL_ORGANIZATION_UNITS HOU,
    HR_LOCATIONS LOC,JA_IN_HR_ORGANIZATION_UNITS HR_ORG WHERE 1 = 1 AND
    PLA.ORGANIZATION_ID = :b1 AND TRUNC(PLA.CREATION_DATE) >= :b2 AND
    TRUNC(PLA.CREATION_DATE) <= :b3 AND HOU.ORGANIZATION_ID =
    PLA.ORGANIZATION_ID AND LOC.LOCATION_ID = PLA.LOCATION_ID AND
    HR_ORG.ORGANIZATION_ID = PLA.ORGANIZATION_ID AND HR_ORG.LOCATION_ID =
    PLA.LOCATION_ID AND TRANSACTION_ID = 19 AND INVENTORY_ITEM_ID != 0 AND
    NVL(ROUNDING_ID,1) != -1 AND RG_OTH.SOURCE_REGISTER_ID = PLA.REGISTER_ID
    AND RG_OTH.SOURCE_REGISTER = 'PLA' AND RG_OTH.TAX_TYPE IN (
    'EXCISE_EDUCATION_CESS' )
    Tkproff from PROD.
    call count cpu elapsed disk query current rows
    Parse 1 0.01 0.01 0 0 0 0
    Execute 1 0.04 0.03 0 0 0 0
    Fetch 1 973.41 1724.95 757187 789442 0 1
    total 3 973.46 1725.01 757187 789442 0 1
    Tkproff from CLONE of PROD.
    call count cpu elapsed disk query current rows
    Parse 1 0.06 0.05 1 789 0 0
    Execute 1 0.00 0.00 0 0 0 0
    Fetch 1 0.73 0.72 6 30594 0 1
    total 3 0.79 0.78 7 31383 0 1

    wins wrote:
    SELECT NVL(SUM(RG_OTH.DEBIT),0),NVL(SUM(RG_OTH.CREDIT),0)  
    FROM
    JA_IN_PLA PLA,JAI_RG_OTHERS RG_OTH,HR_ALL_ORGANIZATION_UNITS HOU,
    HR_LOCATIONS LOC,JA_IN_HR_ORGANIZATION_UNITS HR_ORG  WHERE 1 = 1  AND
    PLA.ORGANIZATION_ID = :b1  AND TRUNC(PLA.CREATION_DATE) >= :b2  AND
    TRUNC(PLA.CREATION_DATE) <= :b3  AND HOU.ORGANIZATION_ID =
    PLA.ORGANIZATION_ID  AND LOC.LOCATION_ID = PLA.LOCATION_ID  AND
    HR_ORG.ORGANIZATION_ID = PLA.ORGANIZATION_ID  AND HR_ORG.LOCATION_ID =
    PLA.LOCATION_ID  AND TRANSACTION_ID = 19  AND INVENTORY_ITEM_ID != 0  AND
    NVL(ROUNDING_ID,1) != -1  AND RG_OTH.SOURCE_REGISTER_ID = PLA.REGISTER_ID 
    AND RG_OTH.SOURCE_REGISTER = 'PLA'  AND RG_OTH.TAX_TYPE IN (
    'EXCISE_EDUCATION_CESS'  )
    Tkproff from PROD.
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        1      0.01       0.01          0          0          0           0
    Execute      1      0.04       0.03          0          0          0           0
    Fetch        1    973.41    1724.95     757187     789442          0           1
    total        3    973.46    1725.01     757187     789442          0           1
    Tkproff from CLONE of PROD.
    call     count       cpu    elapsed       disk      query    current        rows
    Parse        1      0.06       0.05          1        789          0           0
    Execute      1      0.00       0.00          0          0          0           0
    Fetch        1      0.73       0.72          6      30594          0           1
    total        3      0.79       0.78          7      31383          0           1
    As others have pointed out, this looks like a change in execution plan. At a guess, the PROD database is doing a tablescan somewhere (physical reads is approximately equal to logical reads is a pointer).
    There are many reasons why this could happen, continuing with the guesswork - we note that the statement was re-optimised (hard parsed) in the clone, but used an existing cursor in production (logical I/O = 0 in prod, 789 in clone). So the plan you got in the clone was the one that Oracle thought best for the inputs you had supplied. The plan in prod could have been produced as the response to a completely different set of input; since you have two bind variables applied to a range based predicated and one bind variable with equality it's possible that you have a histogram that makes a difference on the equality column, alternatively the range of dates used to generate the original plan was very different from the range used in the test.
    Regards
    Jonathan Lewis
    http://jonathanlewis.wordpress.com
    Author: <b><em>Oracle Core</em></b>

  • Error 9 reading message database during Expire Maintenance

    I have scheduled maintenance to perform an expire on my post office
    Processing information for this run:
    Path to PO = servername/mail:\groupwse\wcicc_po
    Post Office= WCICC_POST
    User = All
    Action = Expire
    Age Limit = Thursday, July 1, 2010 - 8:00 pm (60 days)
    Trash Limit = 15 days
    - Exp items = mail, calendar, doc refs, Inbox, Outbox
    Verbose = Yes
    Upd DiskSpace= No
    Output log = servername/mail:\groupwse\wcicc_po\wpcsout\chk\gwexpire.log
    I keep receiving the following error
    ================================================== ==============================
    ===== TASK LOG - 1305 (4c7c134e.ckl) ===========================================
    ================================================== ==============================
    Checking for items matching purge criteria
    Error 9- MESSAGE database read error BAD_IX (0xC00E)
    Suggestion- Check physical consistency of database, rebuild if errors found
    PROCESSING COMPLETED- total processing time: 0:00:00
    ================================================== ==============================
    ===== JOB LOG SUMMARY (4c7c0dcd.ckl) ===========================================
    ================================================== ==============================
    *** User databases found: 1049
    *** Total bytes reclaimed: 37799936
    *** Average per database: 36034
    Processing completed
    ***** OVERALL STATS FOR THIS RUN *****
    Uncorrectable conditions encountered:
    CODE DESCRIPTION COUNT
    9 Errors reading message databases................... 1
    Correctable conditions encountered:
    CODE DESCRIPTION COUNT
    39 Unrecognized or invalid files in mail directories.. 2
    66 GWCheck log files in log directory................. 1
    What message databse is this?
    The previous lines show that msg254.db processing completed without errors. When I look in ofmsg directory, 254 is the last message database.
    Thanks for any help.

    lfeltswcicc,
    It appears that in the past few days you have not received a response to your
    posting. That concerns us, and has triggered this automated reply.
    Has your problem been resolved? If not, you might try one of the following options:
    - Visit http://support.novell.com and search the knowledgebase and/or check all
    the other self support options and support programs available.
    - You could also try posting your message again. Make sure it is posted in the
    correct newsgroup. (http://forums.novell.com)
    Be sure to read the forum FAQ about what to expect in the way of responses:
    http://forums.novell.com/faq.php
    If this is a reply to a duplicate posting, please ignore and accept our apologies
    and rest assured we will issue a stern reprimand to our posting bot.
    Good luck!
    Your Novell Product Support Forums Team
    http://forums.novell.com/

  • Adding Temp tablespace to physical stand by database?

    I am getting the below error when i try to load data using SQL loader from physical stand by database to another database after making the physical stand by database in read only mode.
    ORA-25153: Temporary Tablespace is Empty.
    On primary database when i query
    SQL>select ts#,name from v$tablespace;
    TS# NAME
    2 TEMP
    On physical stand by when i query
    SQL>select ts#,name from v$tablespace;
    TS# NAME
    2 TEMP
    On primary DB when i query
    select name from v$tempfile where ts#=2;
    NAME
    /dev/vx/rdsk/oradata/tempfile0101
    On standby when i query
    SQL>select name from v$tempfile where ts#=2;
    no rows selected
    At this point do i need to add datafile to the TEMP tablespace of stand by database or just need to add TEMP tablespace to stand by database.?
    DB version:9.2.0.6
    Thank You all...

    Can you make sure that /dev/vx/rdsk/oradata/tempfile0101 is copied to standby site during the standby creation. Often it happens that the hot backups are copied to standby ste and generally they dont contain temp files. If the files is present , then i'll suggest you to do a quick bounce of standby instance to make sure that controlfile attempted to access it. You can also try recreating the standby control file on promary and copy it to standby site along with the tempfile and start the instance with new control file.
    If you want to add temp files to the standby instance, the only option you have is to add them on primary site. If you have standby_file_management as auto they will get copied over. If not you can copy the files to standby instance and restart the recovery.
    Please let us know if any of the hints are applicable to your case.
    -Ravi

  • High user input output (I/O) and physical reads

    Hi guys
    Recently we have noticed that our database performance degraded significantly. as we looked around in grid control we noticed that the user IO and Physical reads are really high which cause the database to be laggy.
    at first we thought it was memory problem, so we added 2gb to sga. we have set sga to be automatic and it's been like this for the past 2 years.
    how do i trouble shoot this problem. i haven't found any troubleshooting guide for it yet.
    please instruct me on how to solve it
    database: 10.2.0.4 sparc
    regards
    Sina

    Top 5 Timed events
    db file sequential read          23,582          679          29          46.3     User I/O
    CPU time                                        626                    42.7     
    db file scattered read     3,089     70     23     4.8     User I/O
    db file parallel write     3,478     28     8     1.9     System I/O
    log file parallel write     4,201     24     6     1.7     System I/O
    SGA Memory Summary
    SGA regions     Begin Size (Bytes)     End Size (Bytes) (if different)
    Database Buffers     2,768,240,640     2,835,349,504
    Fixed Size     2,050,240     
    Redo Buffers     14,721,024     
    Variable Size     3,657,439,040     3,590,330,176
    Process Memory Summary
         Category     Alloc (MB)     Used (MB)     Avg Alloc (MB)     Std Dev Alloc (MB)     Max Alloc (MB)     Hist Max Alloc (MB)     Num Proc     Num Alloc
    B     Other     569.22     0     2.62     3.14     22     24     217     217
         Freeable     101.63     0.00     0.77     0.45     3          132     132
         SQL     91.51     45.35     0.44     0.76     4     78     209     192
         PL/SQL     12.50     5.57     0.06     0.07     0     4     217     217
         JAVA     5.40     5.38     1.08     0.09     1     2     5     5
    E     Other     603.20          3.03     3.62     22     24     199     199
         SQL     115.21     64.78     0.60     1.67     21     78     191     182
         Freeable     112.31     0.00     0.83     0.43     3          135     135
         PL/SQL     13.89     5.94     0.07     0.12     1     4     199     199
         JAVA     8.93     8.89     1.12     0.23     2     2     
    for some reason i can't paste a table into this post but if you want i can email you above tables

  • No physical reads, plenty of consistant gets

    Hi All,
    Oracle v11.2 on Linux.
    Please have a look at the query I ran and the output. The SQL_ID is of a SELECT command.
    What does this situation represents, where there are zero physical reads and plenty of consistant gets ?
    For consistant gets, we do read undo information (correct ??), if that undo is read from disk, will that be a "physical read"? i.e. if we read disks for consistant gets, will that be counted under physical reads or not ?
    How can I describe the exact data retrival of the command here? Is it the case of "everything it needs is found in the buffer cache" ?
    select a.sid, a.value , B.NAME ,  s.sql_id
    from v$sesstat a, v$statname b, v$session s
    where A.STATISTIC# = B.STATISTIC#
    and b.name in ( 'redo size','physical read bytes','physical reads cache','consistent gets' )
    and a.sid = s.sid
    and a.sid=1018
    order by a.sid;
           SID      VALUE NAME                                                             SQL_ID
          1018    7281396 consistent gets                                                  434u36htuz0s9
          1018          0 physical reads cache                                             434u36htuz0s9
          1018          0 physical read bytes                                              434u36htuz0s9
          1018       4448 redo size                                                        434u36htuz0s9
    4 rows selected.Thanks in advance.

    >
    There are no physical reads, so weather its doing consistant-gets or not, can I say, all data required for the SELECT was in buffer cache ?
    >
    The data for those system views is cached in memory so Oracle does not read the disk (except at startup) to gather the information.
    Some static information, like dictionary objects, is stored stored on disk in the system tablespace but this data is read when the database is mounted and stored in memory structures.
    Other dynamic information, like session info, is only stored in memory structures (similar to C arrays) and Oracle can query these as if they were tables.
    So no, the data was not in the buffer cache. It was already in system memory.

  • Unable to reduce  Physical Reads

    Hi
    Problem:
    Need to reduce the Physical reads in Oracle 8.1.7
    Information:
    Optimizer_mode= Choose
    Statistics will not be gathered.
    Intially the cache hit ratio is 18%. At this point when we checked the SQL Statement
    SELECT a32,
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    a147 AS Service_Subsidary,
    a89 AS StaffInd,
    a88 AS SubsidiaryInd
    FROM doctaba
    WHERE a94 = 'CCOC_CARDS_CCA_060824_6'
    AND a40 IN ('3','4','5')
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    81 db block gets
    5020 consistent gets
    3909 physical reads
    0 redo size
    401 bytes sent via SQL*Net to client
    311 bytes received via SQL*Net from client
    2 SQL*Net roundtrips to/from client
    0 sorts (memory)
    0 sorts (disk)
    1 rows processed.
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    0 recursive calls
    81 db block gets
    3717 consistent gets
    3576 physical reads
    0 redo size
    401 bytes sent via SQL*Net to client
    311 bytes received via SQL*Net from client
    2 SQL*Net roundtrips to/from client
    0 sorts (memory)
    0 sorts (disk)
    1 rows processed.
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    Please advice!!
    Cheers
    Ramkannan.A

    Buffer hit cache ratios are totally meaningless as was proven many years ago by Connor's brilliant little utility that allows you to dial in any ratio you want.
    The reason your are getting FTEs is because your totally antiquated version of the product, never supported during the current century, is that it thinks FTEs cost less than using any indexes that may (or may not) exist. You've not established in your email that there are any indexes or posted DDL or provided much of anything else that would be helpful.
    I would think moving from the Jurassic to 10.2.0.4, or above, would be your first priority.

  • Question on physical reads

    Is RMAN I/Os accounted in physical reads stat?
    I mean, do the blocks read from disk by RMAN to backup the database get accounted in physical reads statistic?
    One of our databases has a value for physical read total IO requests higher than physical reads so I guess the physical reads missing are RMAN's.
    Thanks in advance

    Statistics have not the same unit so you cannot compare them directly:
    >
    physical read total IO requests
    Number of read requests which read one or more database blocks for all instance activity including application, backup and recovery, and other utilities. The difference between this value and "physical read total multi block requests" gives the total number of single block read requests.
    >
    and
    >
    physical reads     
    Total number of data blocks read from disk. This value can be greater than the value of "physical reads direct" plus "physical reads cache" as reads into process private buffers also included in this statistic.
    >
    You should compare physical read total IO requests with:
    >
    physical read IO requests
    Number of read requests for application activity (mainly buffer cache and direct load operation) which read one or more database blocks per request. This is a subset of "physical read total IO requests" statistic.
    >
    Edited by: P. Forstmann on 9 avr. 2013 12:57

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