Execution Plan change

Hello world

I have this recommendation in Enterprise Manager, I would like to implement the first recommendation where there is a best execution plan that comes with the benefit of 99.7%. Its easy to implement using Enterprise manager by clicking just. But I would like to know how I can change execution plan using sqlplus. And if I want to return to the original plan, how can I do? Thank you in advance for your precious time really appreciate it.

recommendation.png

Yes, you can restore it-here, you will...

http://docs.Oracle.com/CD/B28359_01/server.111/b28274/sql_tune.htm#CHDIDBBG

Tags: Database

Similar Questions

  • The execution plan changes for the same query.

    Hi all

    This issue was raised before also, but still not able to find the real cause of this.

    Thread1:
    Re: Research of fragmentation of the table in Oracle 8.1.6.3.0

    Thread2:
    CBC latch and buffer busy await you on the same table.

    It comes, sometimes hammers server 100% CPU utilization with free latch and buffer busy wait events.

    We found a single query consumes high CPU usage that is run by different sessions.

    This query have two types of execution plans, where one is accurate and is not (its primary key hit index index no appropriate means present on the table)

    Because its primary key index hit repeatedly at various sessions, some sessions are powerful db file sequential read and a few sessions waiting buffer busy waits for event. Also during this time a few sessions waiting for latch free event.

    My doubt is how to sql even with different literal values execution plan changes and causes a prob.
    select count(*),event from v$session_wait group by event;
  COUNT(*) EVENT
---------- ----------------------------------------------------------------
       165 SQL*Net message from client
         1 SQL*Net message to client
         3 buffer busy waits
         2 db file parallel read
        18 db file sequential read
        10 latch free
         5 log file sync
         1 pmon timer
         6 rdbms ipc message
         1 smon timer

SQL> select sid from v$session_wait where event='db file sequential read';
       SID
----------
        26
        58
        82
       107
       116
       223
       212
       203
       192
       173
       161
       157
       150
       147
       254
       238
       229
       112
       101
        81
        68

SQL> select spid, sid, s.serial#, p.program from v$session s, v$process p where paddr=addr and sid=&SID;
Enter value for sid: 161
old   1: select spid, sid, s.serial#, p.program from v$session s, v$process p where paddr=addr and sid=&SID
new   1: select spid, sid, s.serial#, p.program from v$session s, v$process p where paddr=addr and sid=161

SPID             SID    SERIAL# PROGRAM
--------- ---------- ---------- ------------------------------------------------
4231             161      49569 oracle@tfrdb3 (TNS V1-V3)


SQL> select sql_text
from v$process a,
     v$session b,  2    3
     v$sql c
where a.addr = b.paddr and
     b.sql_hash_value = c.hash_value and
    a.spid = &PID;  4    5    6    7
Enter value for pid: 4231
old   7:     a.spid = &PID
new   7:     a.spid = 4231

SQL_TEXT
--------------------------------------------------------------------------------
SELECT ERROR,TIME_STAMP,O_RESOURCE,QUEUE,NEW_QUEUE FROM LOG WHERE ID = '09292AMR
10B41FE' AND TYPE IN (11, 28, 25, 18, 60, 13) AND (LOG_SEQ>'234225222' OR TYPE =
 18 AND LOG_SEQ='234225222') ORDER BY TIME_STAMP ASC

SQL> set autotrace traceonly exp
SQL> SELECT ERROR,TIME_STAMP,O_RESOURCE,QUEUE,NEW_QUEUE FROM amrwf1.LOG WHERE ID = '09292AMR10B41FE' AND TYPE IN (11, 28, 25, 18, 60, 13) AND (LOG_SEQ>'234225222' OR TYPE =18 AND LOG_SEQ='234225222') ORDER BY TIME_STAMP ASC;

Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=CHOOSE (Cost=11 Card=2 Bytes=126)
   1    0   SORT (ORDER BY) (Cost=11 Card=2 Bytes=126)
   2    1     CONCATENATION
   3    2       TABLE ACCESS (BY INDEX ROWID) OF 'LOG' (Cost=4 Card=1
          Bytes=63)

   4    3         INDEX (UNIQUE SCAN) OF 'PK_LOG_LOG_SEQ' (UNIQUE) (Co
          st=3 Card=1)

   5    2       TABLE ACCESS (BY INDEX ROWID) OF 'LOG' (Cost=4 Card=1
          Bytes=63)

   6    5         INDEX (RANGE SCAN) OF 'PK_LOG_LOG_SEQ' (UNIQUE) (Cos
          t=3 Card=1)


SQL> select spid, sid, s.serial#, p.program from v$session s, v$process p where paddr=addr and sid=&SID;
Enter value for sid: 147
old   1: select spid, sid, s.serial#, p.program from v$session s, v$process p where paddr=addr and sid=&SID
new   1: select spid, sid, s.serial#, p.program from v$session s, v$process p where paddr=addr and sid=147

SPID             SID    SERIAL# PROGRAM
--------- ---------- ---------- ------------------------------------------------
6255             147      38306 oracle@tfrdb3 (TNS V1-V3)

SQL> select sql_text
from v$process a,
     v$session b,
     v$sql c  2    3
where a.addr = b.paddr and
     b.sql_hash_value = c.hash_value and
    a.spid = &PID;  4    5    6    7
Enter value for pid: 6255
old   7:     a.spid = &PID
new   7:     a.spid = 6255

SQL_TEXT
--------------------------------------------------------------------------------
SELECT ERROR,TIME_STAMP,O_RESOURCE,QUEUE,NEW_QUEUE FROM LOG WHERE ID = '09273AMR
62B4894' AND TYPE IN (11, 28, 25, 18, 60, 13) AND (LOG_SEQ>'223324996' OR TYPE =
 18 AND LOG_SEQ='223324996') ORDER BY TIME_STAMP ASC


SQL> set autotrace traceonly exp
SQL> SELECT ERROR,TIME_STAMP,O_RESOURCE,QUEUE,NEW_QUEUE FROM amrwf1.LOG WHERE ID = '09273AMR62B4894' AND TYPE IN (11, 28, 25, 18, 60, 13) AND (LOG_SEQ>'223324996' OR TYPE =18 AND LOG_SEQ='223324996') ORDER BY TIME_STAMP ASC;

Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=CHOOSE (Cost=1538 Card=736 Bytes=
          46368)

   1    0   SORT (ORDER BY) (Cost=1538 Card=736 Bytes=46368)
   2    1     TABLE ACCESS (BY INDEX ROWID) OF 'LOG' (Cost=1527 Card=7
          36 Bytes=46368)

   3    2       INDEX (RANGE SCAN) OF 'LOG_ID' (NON-UNIQUE) (Cost=32 C
          ard=736)



SQL> select spid, sid, s.serial#, p.program from v$session s, v$process p where paddr=addr and sid=&SID;
Enter value for sid: 82
old   1: select spid, sid, s.serial#, p.program from v$session s, v$process p where paddr=addr and sid=&SID
new   1: select spid, sid, s.serial#, p.program from v$session s, v$process p where paddr=addr and sid=82

SPID             SID    SERIAL# PROGRAM
--------- ---------- ---------- ------------------------------------------------
6172              82      45378 oracle@tfrdb3 (TNS V1-V3)


SQL> select sql_text
from v$process a,
     v$session b,
     v$sql c
where a.addr = b.paddr and
     b.sql_hash_value = c.hash_value and  2
  3      a.spid = &PID;  4    5    6    7
Enter value for pid: 6172
old   7:     a.spid = &PID
new   7:     a.spid = 6172

SQL_TEXT
--------------------------------------------------------------------------------
INSERT INTO LOG (ID,TIME_STAMP,TYPE,ERROR,INSTANCE,RULE_NUM,RULE_TYPE,PRIORITY,F
LAGS,NAME,BATCH,O_RESOURCE,QUEUE,NEW_QUEUE,SERVER,FORM,WORKSET) VALUES (:V001,:V
002,11,0,0,3,1,0,1,:V003,:V004,:V005,:V006,:V007,:V008,:V009,:V010)

INSERT INTO LOG (ID,TIME_STAMP,TYPE,ERROR,INSTANCE,RULE_NUM,RULE_TYPE,PRIORITY,F
LAGS,NAME,BATCH,O_RESOURCE,QUEUE,NEW_QUEUE,SERVER,FORM,WORKSET) VALUES (:V001,:V
002,11,0,0,3,1,0,1,:V003,:V004,:V005,:V006,:V007,:V008,:V009,:V010)

INSERT INTO LOG (ID,TIME_STAMP,TYPE,ERROR,INSTANCE,RULE_NUM,RULE_TYPE,PRIORITY,F
LAGS,NAME,BATCH,O_RESOURCE,QUEUE,NEW_QUEUE,SERVER,FORM,WORKSET) VALUES (:V001,:V
002,11,0,0,3,1,0,1,:V003,:V004,:V005,:V006,:V007,:V008,:V009,:V010)

SQL_TEXT
--------------------------------------------------------------------------------

INSERT INTO LOG (ID,TIME_STAMP,TYPE,ERROR,INSTANCE,RULE_NUM,RULE_TYPE,PRIORITY,F
LAGS,NAME,BATCH,O_RESOURCE,QUEUE,NEW_QUEUE,SERVER,FORM,WORKSET) VALUES (:V001,:V
002,11,0,0,3,1,0,1,:V003,:V004,:V005,:V006,:V007,:V008,:V009,:V010)

INSERT INTO LOG (ID,TIME_STAMP,TYPE,ERROR,INSTANCE,RULE_NUM,RULE_TYPE,PRIORITY,F
LAGS,NAME,BATCH,O_RESOURCE,QUEUE,NEW_QUEUE,SERVER,FORM,WORKSET) VALUES (:V001,:V
002,11,0,0,3,1,0,1,:V003,:V004,:V005,:V006,:V007,:V008,:V009,:V010)

INSERT INTO LOG (ID,TIME_STAMP,TYPE,ERROR,INSTANCE,RULE_NUM,RULE_TYPE,PRIORITY,F
LAGS,NAME,BATCH,O_RESOURCE,QUEUE,NEW_QUEUE,SERVER,FORM,WORKSET) VALUES (:V001,:V

SQL_TEXT
--------------------------------------------------------------------------------
002,11,0,0,3,1,0,1,:V003,:V004,:V005,:V006,:V007,:V008,:V009,:V010)

INSERT INTO LOG (ID,TIME_STAMP,TYPE,ERROR,INSTANCE,RULE_NUM,RULE_TYPE,PRIORITY,F
LAGS,NAME,BATCH,O_RESOURCE,QUEUE,NEW_QUEUE,SERVER,FORM,WORKSET) VALUES (:V001,:V
002,11,0,0,3,1,0,1,:V003,:V004,:V005,:V006,:V007,:V008,:V009,:V010)
    How to avoid this... why its different execution plan using (I mean bad index PK)

    Is it possible to avoid this?

    If any details please check out some of my previous post on this specific URL (above)

    -Yasser

    My doubt is how to sql even with different literal values execution plan changes and causes a prob.

    Different literal values cause analysis difficult.
    Hard analysis includes the re-evaluation of the best path.
    Literal value is included in the assessment of the selectivity for the scan interval (log_seq >...)

    See
    http://www.centrexcc.com/A%20Look%20under%20The%20Hood%20Of%20CBO%20-%20The%2010053%20Event.ppt.PDF
    http://www.centrexcc.com/fallacies%20Of%20The%20Cost%20Based%20Optimizer.PDF
    more the book of Jonathan Lewis which other threads, I believe that you already have.

    You must lower your CPU.
    Previous discussions, if the situation is still the same, it sounded like hard analysis particularly with this SELECTION against the NEWSPAPER plays an important role in that.

    How to avoid this... why its different execution plan using (I mean bad index PK)

    The points raised in the previous discussion remain valid.
    -Do you have access to this SQL to change?
    for example using bind variable or trick it if necessary due to problems caused by data as discussed in the previous thread.
    - Or you could it repoint the view to a view and a hint?
    -If a particular user makes this sql, could affect you cursor_sharing just for this user. If not, you should consider implementing pan-Canadian database.

    Oracle 8.1.6 still?

  • Execution plan will change if I use the variable binding instead of the literal value?

    Hi guys,.

    Suppose I have a select "... Of... WHERE ID = 2 and... "if I go to use the variable binding instead of the literal value 2," SELECT... " Of... WHERE ID =: p_id and... ", the execution plan change?
    I test multiple statements, the plan does not change, but I don't know if it would even as well as in some other cases.
    Someone at - it ideas?

    Thank you very much.

    Anneso wrote:
    Hi, sorry for the unclear post, it's 11 GR 2.

    As Sybrand already mentioned, there are a lot of change that came in the implementation of the bind variable in some versions of Oracle db. Since you're on 112, it is still true with the introduction of Adaptive Cursor Sharing . Please have a read on it since the post below written by the development of Oracle optimizer group.
    http://blogs.Oracle.com/optimizer/entry/why_are_there_more_cursors_in_11g_for_my_query_containing_bind_variables_1

    Aman...

  • Change of particular execution plan

    Hi all

    Oracle Version: 10.2.0.4

    Below mentioned query runs fine when only a single value is passed for the paragraph, but chooses to full table scan whenever multiple values is passed to IN would adopt.


    Could someone help me please know why the execution plan changes just passing multiple values IN the clause...

    Published by: Yasu on March 18, 2011 12:07 
    and c.orgid(+)=o.orgid
and o.orgid > 4

    OuterJoin on ORGID is not sensible if you apply a filter of ORGID greaterthan 4 also.
    The OuterJoin returns that value the NULL and NULL for ORGID would fail the filter.

    Hemant K Collette

  • Version 12: Same SQL, another scheme == > different execution plan?

    I'm testing a huge application with a database middleware sophisticated against the Oracle 12 database. So far, it works well with Pervasive SQL, MSSQL and Oracle 8 database... 11.

    There are many questions about execution plans changed from Version 11 to 12. Oracle will tell what all of the improvements are (or at least have to improvements), and I can't really denied him. It's not the subject.

    But I met some SQLs with horrible execution time, especially connected to Crystal Reports. Whenever I tried to check them, the queries have been executed quickly. As far as I can see, this has to do with the schema/user who executes the SQL statement in a first time. Here are the details:

    • = ADMIN, DML = GUI DDL: all data are stored in a scheme of the ADMIN. The ADMIN user creates the tables, views and so on. It grants access to and creates synonyms for users, but it cannot modify the data using DML, given that triggers prevent him. End users, named 'GUI' users, are allowed to use the DML, but they have no privileges DDL.

    • Database of reports (on paper) are generally quite complex. They have only a limited data set (must fit on sheets of paper!), and the Oracle optimizer optimizes often against this goal. Because Crystal Reports generates no advice, most of the reports are based on a view ADMIN. < xyz > (with the necessary information) and are accessible via a GUI. < xyz > synonym of user GUI.

    • Crystal Reports running slowly (~ 5 minutes) connected as a GUI. I export it, get the SQL export, log in as an ADMINISTRATORand run the query, it works quickly (~ 2 seconds). Well, I've probably changed some white space, the line endings and others then copy / paste, I don't?

    • I tried many things, connecting both GUI and ADMIN, simplifying the application, execution and so on. Then I got confused version of who this query: when the ADMIN has added an additional space character it was fast, removed again and it was slow again. Whitespace have an influence on the execution plan? Probably not, and if yes, my vision of the world would collapse.

    • Later, I found out: in Version 12, depends on the user executing this query. Nail down us the source of the query for the synonym GUI. < xyz >. Let us make a new version of it (coded by white space - smile), and if run you it like GUI first, it's slow. Even if you re - log on as ADMINISTRATOR, the same version of this query is still slow. (This is a bug!)

    Question 1: When I prepend the SQL with 'EXPLAIN PLAN FOR', I seem to be changing. As GUI has no plan_table and no privilege to explain a plan, I can't spy on the implementation plan of 'bad '. I don't want to give too much GUI, and I fear it could alter the execution plan. Is there a trick to get the plan of execution of a SQL statement in v$ sql or v$ sqlarea? (Means: execute the query: GUI and explain it as an ADMINISTRATOR)

    Question 2: Is this on the privileges of the GUI? What you think, what direction will further investigate?

    Oracle database generates an execution plan based on SQL, the dictionary, the statistics, the privileges of the user of the analysis and database and session settings. One of the privileges is GRANT MERGE [ALL] DISPLAY, which was responsible for the difference in this particular example and in this particular version.

    When you log on as another user and run the same code in SQL, Oracle database verifies all required components before she reuses the old execution plan. This is a minor bug, but it is.

    In the example, the privilege GRANT MERGE ANY NOTICE was given implicitly by the DBA privilege. Because MERGE ANY VIEW disables security controls, the privilege of s/n, default, also disables security controls. This is not a desired behavior from the DBA privilege.

  • 10.2.0.5 - execution plan has changed because of the link stealthily

    Hi guys,.

    Our DB server has very heavy use of the CPU on some days.
    After investigation, it is due to a particular change in SQL in the execution plan.

    For example, this SQL has SQL_ID: 123, with execution plan 2 (hash value).
    PLAN 1 - ABC [GOOD] - scan of systematic index
    PLAN 2 - DEF [BAD] - full analysis

    Problem SQL < not really sql, for example simplify >
    SELECT *.
    XX
    WHERE CRITERIA =: B1;


    I would like to identify the value he threw a look that caused the change in plan 1 plan 2 plan.
    In any case, I know?
    I also have the SQLT report. But can't really understand the part of connection overview of the report.

    Please advise.
    Thank you

    Using DBMS_XPLAN. DISPLAY_CURSOR, you can use the format mask of '+ PEEKED_BINDS', for example

    select * from table(dbms_xplan.display_cursor('','','+PEEKED_BINDS'));

    Or you can watch V$ SQL. BIND_DATA or, possibly, V$ SQL_PLAN. OTHER_XML although I'm not sure which version the links peeked appear in the latter.
    You can use DBMS_SQLTUNE. EXTRACT_BIND/S on the amount GROSS of V$ SQL. (BIND_DATA so) you a license for the tuning pack and b) there is in this version.

    Published by: Dom Brooks on November 23, 2012 09:54

  • 12 c parallel execution Plans

    Hello world

    I have a little a problem of performance on 12 c that gives me a little trouble at the head. I moved from 11 to 12 databases and no amendment of the application have been made. Our requests are generated somewhat dynamically, so that they are the same thing every time.

    Let's start with the execution plan I get:

    SQL > select * from table (dbms_xplan.display ());


    PLAN_TABLE_OUTPUT

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

    Hash value of plan: 3567104424

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

    | ID | Operation                                            | Name                  | Lines | Bytes | Cost (% CPU). Time |    TQ | IN-OUT | PQ Distrib.

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

    |   0 | SELECT STATEMENT |                       |    55.  7095 |  3764 (1) | 00:00:01 |        |      |            |

    |   1.  COORDINATOR OF PX |                       |       |       |            |          |        |      |            |

    |   2.   PX SEND QC (ORDER). : TQ10006 |    55.  7095 |  3764 (1) | 00:00:01 |  Q1, 06 | P > S | QC (ORDER).

    |   3.    SORT ORDER BY |                       |    55.  7095 |  3764 (1) | 00:00:01 |  Q1, 06 | SVCP |            |

    |   4.     PX RECEIVE                                       |                       |    55.  7095 |  3763 (1) | 00:00:01 |  Q1, 06 | SVCP |            |

    |   5.      RANGE OF SEND PX | : TQ10005 |    55.  7095 |  3763 (1) | 00:00:01 |  Q1, 05 | P > P | RANGE |

    |   6.       UNIQUE FATE |                       |    55.  7095 |  3763 (1) | 00:00:01 |  Q1, 05 | SVCP |            |

    |*  7 |        HASH JOIN                                     |                       |    55.  7095 |  3762 (1) | 00:00:01 |  Q1, 05 | SVCP |            |

    |   8.         PX RECEIVE                                   |                       |   801 | 50463 |  3696 (1) | 00:00:01 |  Q1, 05 | SVCP |            |

    |   9.          PX SEND HASH | : TQ10003 |   801 | 50463 |  3696 (1) | 00:00:01 |  Q1, 03 | P > P | HASH |

    | * 10 |           HASH JOIN                                  |                       |   801 | 50463 |  3696 (1) | 00:00:01 |  Q1, 03 | SVCP |            |

    |  11.            RECEIVE PX |                       |   801 | 40851 |  2333 (1) | 00:00:01 |  Q1, 03 | SVCP |            |

    |  12.             PX SEND BROADCAST | : TQ10002 |   801 | 40851 |  2333 (1) | 00:00:01 |  Q1, 02 | P > P | BROADCAST |

    |  13.              NESTED LOOPS |                       |   801 | 40851 |  2333 (1) | 00:00:01 |  Q1, 02 | SVCP |            |

    |  14.               KIND OF BUFFER.                       |       |       |            |          |  Q1, 02 | ISSUE |            |

    |  15.                RECEIVE PX |                       |       |       |            |          |  Q1, 02 | SVCP |            |

    |  16.                 PX SEND HASH | : TQ10000 |       |       |            |          |        | S > P | HASH |

    |  17.                  NESTED LOOPS |                       |   823. 31274 |  1509 (1) | 00:00:01 |        |      |            |

    | * 18.                   TABLE ACCESS BY ROWID INDEX BATCH | PAGED_LOOKUP_PKS |   500 |  9500 |     3 (0) | 00:00:01 |        |      |            |

    | * 19.                    INDEX RANGE SCAN | PAGED_LOOKUP_PKS_IDX2 |     1.       |     2 (0) | 00:00:01 |        |      |            |

    |  20.                   TABLE ACCESS BY ROWID INDEX BATCH | BILL_ITEM |     2.    38.     4 (0) | 00:00:01 |        |      |            |

    | * 21.                    INDEX RANGE SCAN | BILL_ITEM_FK2 |     4.       |     2 (0) | 00:00:01 |        |      |            |

    | * 22.               INDEX UNIQUE SCAN | PK_INSERTION |     1.    13.     1 (0) | 00:00:01 |  Q1, 02 | SVCP |            |

    |  23.            ITERATOR BLOCK PX |                       |  1548K |    17 M |  1353 (2) | 00:00:01 |  Q1, 03 | ISSUE |            |

    |  24.             FULL RESTRICTED INDEX SCAN FAST | BOOKING_ACCOUNT_1 |  1548K |    17 M |  1353 (2) | 00:00:01 |  Q1, 03 | SVCP |            |

    |  25.         PX RECEIVE                                   |                       | 22037 |  1420K |    65 (2) | 00:00:01 |  Q1, 05 | SVCP |            |

    |  26.          PX SEND HASH | : TQ10004 | 22037 |  1420K |    65 (2) | 00:00:01 |  Q1, 04 | S > P | HASH |

    |  27.           SELECTOR PX |                       |       |       |            |          |  Q1, 04 | SCWC |            |

    |  28.            TABLE ACCESS FULL | CONTACT | 22037 |  1420K |    65 (2) | 00:00:01 |  Q1, 04 | SCWP |            |

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

    Information of predicates (identified by the operation identity card):

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

    7 - access ("ACCOUNT_ID" ="ACCOUNT_ID")

    10 - access ("BOOKING" ="BOOKING")

    18 - filter("T1".") SEQUENCE_NO' < 501 AND "T1". ("' SEQUENCE_NO" > = 1).

    19 - access("T1".") SESSION_ID '= 123456 AND 'T1'.' SEARCH_ID "= 25)

    21 - access("T1".") N1 "=" BILL_ID")

    22 - access ("BOOKING" = "BOOKING" AND "INSERTION_SET" = "INSERTION_SET" AND "INSERT"="INSERT")

    Note

    -----

    -the dynamic statistics used: dynamic sampling (level = 2)

    -This is an adaptation plan

    -2 directives Plan Sql used for this statement

    51 selected lines.

    Elapsed time: 00:00:00.15

    SQL > spool off

    OK, now let's go through the problem:

    1. It's a development running on a virtual server, and which hosts a few other databases, so the parallel execution is not a good thing. parallel_degree_policy is set to MANUAL, parallel_max_servers and all other parallel_ limits are set to 1 and tables have been changed with the settings of NOPARALLEL. So why is the execution plan always generated with all stages of parallel execution? I don't seem to get rid of in 12 c
    2. Next mystery is that the said plan of the explain command is an adaptation plan, and yet I put the true optimizer_adaptive_reproting_only
    3. Now to the problem of effective enforcement, so I'm playing around with all these settings. The query runs for 3-4 seconds, returning around about 500 cases. However, in some cases this same query with the same input variable races for hours and if I can believe the AWR and ASH reports, read a good 180 GB of data. The main wait event is direct path read temp temp and writing.


    This is not isolated to that one query. I have a few queries now that all display the same behavior, one of them running overnight. I don't seem to get to a standard nested loop execution plans.


    The entire base is a database plug-in and I don't know I just missed something in the new features Guide.

    Would appreciate some ideas.

    Thank you

    If you want to disable parallel execution, you must set parallel_max_servers to zero.  Maybe the optimizer thinks he can use a parallel plan because parallel_max_servers is non-zero (even though the number of slaves available means that it will be serialized to a parallel plan).

    Note that you have a ticket saying dynamic stats have been used.  Maybe you have a 11 for optimizer_dynamic_sampling setting, and allowing Oracle to be very inventive with collection of samples and parallelism.

    You have also 2 SQL instructions in game. These are the things that get associated with objects rather than the instructions, then perhaps someone has been playing with parallelism and managed to associate the parallelism with one of the tables in your query (I am not sure 100% that it is possible, just throw a suggestion).  Take a look at the SQL used for education guidelines.

    To give us a little more information, you can:

    Shoot memory execution plan dbms_xplan.display_cursor ({sql_id}, {number of children}, 'ALL'));

    We show all the parallel settings (see setting the parallel)

    Pull on the parameters of the optimizer for query memory (select name, value of V$ sql_optimizer_env where sql_id = {your sql identifier} and child_number = {your child number})

    Concerning

    Jonathan Lewis

  • Space of bunch of java error when executing execution plan

    I get this error at the start of the execution plan ETL, to the capture of change task.

    I ve tried to change the startclient.bat and using a larger setting... -Xmx1612... I can not set more... (get a JVM error).

    Pls. y at - it suggestions to work around this error? The race AND stop right there... and nothing is loaded.

    TXS.

    Antonio

    Solved... the increase in the parameter - Xmx in startserver.sh did the trick.

    TXS for all your comments.

    Antonio

  • Execution plans

    Hello

    Most of the time that I see the actual execution plan (run time) differs from the plan we get grace explains (plan estimated). or several times the execution plan obtained using "explain plan" differs from the plan we get from 'awrsqrpt.sql' or 'sprepsql.sql '.

    Why does this happen?

    Thank you and best regards.

    One more for the list:
    http://hoopercharles.WordPress.com/2010/01/11/explain-plan-lies-AutoTrace-lies-TKPROF-lies-what-is-the-plan/

    The above shows a test case where same TKPROF displayed the level of poor execution, even when the EXPLAIN of TKPROF command option is not used.

    The best option is to use DBMS_XPLAN. DISPLAY_CURSOR to pull the actual execution directly plan from the memory of the server (or use a 10046 trace to capture execution plans, as the SQL statements are executed). Note that there may be several cursors child in memory for a SQL statement only due to changes in the environment of optimization, permissions on the referenced objects bind peeking, collection of statistics, adaptive cursor sharing, and an improvement in Oracle Database 11.2.0.1 that re - optimizes some SQL statements after execution of a repetition that return numbers significantly different lines in the steps of the execution plan than what has been predicted by the optimizer - in this case even for the SQL statements that make does not bind variables (this feature is called feedback cardinality).

    See this series into three parts in order to recover the actual execution plan:
    http://hoopercharles.WordPress.com/2010/01/30/execution-plans-what-is-the-plan-and-where-do-i-find-it/

    Charles Hooper
    Co-author of "Expert Oracle practices: Oracle Database Administration of the Oak Table.
    http://hoopercharles.WordPress.com/
    IT Manager/Oracle DBA
    K & M-making Machine, Inc.

  • Query Plan changes when a static value is assigned to an update

    I have a table
    SQL> create table test
  2  as
  3  select '001' col
  4    from dual
  5  connect by level <= 15000
  6  /

Table created.

SQL> exec dbms_stats.gather_table_stats('SYSADM','TEST',CASCADE=>TRUE)

PL/SQL procedure successfully completed.
    Now, I want to update the table so that each 5000 lines to be incremented as the value pass
    001.002... and so on.

    I did it.
    SQL> set autotrace traceonly explain
SQL> set timing on
SQL> update test t
  2     set col = (select to_char(trunc(rno/5000)+1,'fm009')
  3             from (select row_number() over(order by rowid) rno,
  4                               rowid
  5                     from test) t1
  6             where t.rowid = t1.rowid)
  7  /

15000 rows updated.

Elapsed: 00:03:49.06

Execution Plan
----------------------------------------------------------
   0      UPDATE STATEMENT Optimizer=ALL_ROWS (Cost=8 Card=15000 Bytes=60000)
   1    0   UPDATE OF 'TEST'
   2    1     TABLE ACCESS (FULL) OF 'TEST' (TABLE) (Cost=8 Card=15000 Bytes=60000)
   3    1     VIEW (Cost=55 Card=15000 Bytes=375000)
   4    3       WINDOW (SORT) (Cost=55 Card=15000 Bytes=60000)
   5    4         TABLE ACCESS (FULL) OF 'TEST' (TABLE) (Cost=8 Card=15000 Bytes=60000)

SQL> rollback
  2  /

Rollback complete.

Elapsed: 00:00:01.00
    It works very well. But what I discovered is. When I change the update above. And replace the
    TO_CHAR (trunc(RNO/5000) + 1, 'fm009') with a static value as '1' the query plan changes and
    It runs very quickly.
    SQL> update test t
  2     set col = (select '1'--to_char(trunc(rno/5000)+1,'fm009')
  3             from (select row_number() over(order by rowid) rno,
  4                               rowid
  5                     from test) t1
  6             where t.rowid = t1.rowid)
  7  /

15000 rows updated.

Elapsed: 00:00:00.01


Execution Plan
----------------------------------------------------------
   0      UPDATE STATEMENT Optimizer=ALL_ROWS (Cost=8 Card=15000 Bytes =60000)
   1    0   UPDATE OF 'TEST'
   2    1     TABLE ACCESS (FULL) OF 'TEST' (TABLE) (Cost=8 Card=15000 Bytes=60000)
   3    1     TABLE ACCESS (BY USER ROWID) OF 'TEST' (TABLE) (Cost=1 Card=1 Bytes=4)

SQL> rollback
  2  /

Rollback complete.

Elapsed: 00:00:01.00
    Why is it so. Can someone explain?

    Karthick_Arp wrote:
    SQL > update of test t
    2 set col = (select to_char (trunc(rno/5000) + 1, 'fm009'))
    3 from (select row_number() over (order by rowid) rno,
    4 rowid
    5 test) t1
    6 where t.rowid = t1.rowid)
    7.

    15000 lines to date.

    Execution plan
    ----------------------------------------------------------
    STATEMENT UPDATE 0 = ALL_ROWS optimizer (cost = card 8 = 15000 bytes = 60000)
    1 0 UPDATE OF 'TEST '.
    2 1 TABLE ACCESS (FULL) 'TEST' (TABLE) (cost = card 8 = 15000 bytes = 60000)
    3 1 VIEW (cost = map 55 = 15000 bytes = 375000)
    4 WINDOW 3 (TRI) (cost = map 55 = 15000 bytes = 60000)
    5 4 TABLE ACCESS (FULL) 'TEST' (TABLE) (cost = card 8 = 15000 bytes = 60000)

    SQL > update of test t
    2 set col = (select '1' - to_char (trunc(rno/5000) + 1, 'fm009'))
    3 from (select row_number() over (order by rowid) rno,
    4 rowid
    5 test) t1
    6 where t.rowid = t1.rowid)
    7.

    15000 lines to date.

    Execution plan
    ----------------------------------------------------------
    STATEMENT UPDATE 0 = ALL_ROWS optimizer (cost = card 8 = 15000 bytes = 60000)
    1 0 UPDATE OF 'TEST '.
    2 1 TABLE ACCESS (FULL) 'TEST' (TABLE) (cost = card 8 = 15000 bytes = 60000)
    3 1 ACCESS TABLE (BY USER ROWID) OF 'TEST' (TABLE) (cost = 1 card = 1 bytes = 4)

    Why is it so. Can someone explain?

    In addition to what Rob has already said, the answer to your question is: given that the optimizer is smart and recognizes that your WINDOW TYPE in your second query (aka NWR) is never accessible and therefore simply ignores this part of the application. It turns it to a simple statement like this:

    update test t
   set col = (select '1'
           from (select rowid
                   from test) t1
           where t.rowid = t1.rowid);

    who can simply access the TEST table for each row of rowid, while your first query should do recursively for each TEST line full table scan. Using a statistics AUTOTRACE, you should see a large difference in e/s logic for both statements.

    Using DBMS_XPLAN. DISPLAY could reveal more details what happens, if you're already on 9i or later version (seems to be 9iR2).

    Kind regards
    Randolf

    Oracle related blog stuff:
    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/

  • OEM12c: in execution plans, no more links to tables (OEM10g has them)

    in the Plan for SQL, version details tab OEM 10g has hyperlinks to the objects mentioned in the implementation plan.

    OEM10g Plan has hyperlinks.jpg

    It seems not to be the case more in OEM12c:

    OEM12c no more hyperlink to table.jpg

    Does anyone know how to activate the ability to directly open the details page of the objects listed in the execution plans?

    Hello

    This feature has been valuable, but unfortunately has not been set up at EM12c.  If you want to access the Cloud control, once connected to the database, the best way is to click on the schema, database objects and then go to the correct data type to search for the object in question.  If you are looking for information on the object in the execution plan, then the best way to see it is via SQL Monitor if the process has not aged.  If it has, then use SQL statements search, (under the menu Performance/SQL for the database that you are connected) and then do a search for cache, CWA and other, you know you want to watch for the SQLID in question.

    I hope this helps!

    Kevin Pot' wine-Gorman

  • Cost of the execution plan is different in the two databases

    Hi gurus,

    I have two databases, which are 12 C.

    The execution plan cost is different in the two databases for the same query.

    is it possible to copy the execution to another plan.

    Thank you in advance

    Kind regards

    REDA

    Jr.Raj wrote:

    There are a few differences.

    The machine that has a high cost, has setup up, linux, 2-node RAC, more CPU.

    and

    other machine windows server less Setup and less cpus.

    Please explain, cost really makes a difference.

    Thank you & best regards

    REDA

    You simply can't compare costs like that. It does not work like that. Especially through two different systems.  Here is a very good read: column the COST of the PLAN to EXPLAIN. Oracle FAQ

  • "Execution plan is not available" in OEM.

    Greetings. Try to watch my first Exec Plan here and make the message displayed above in OEM 11 g even executing simple statements like below. I googled this and see only one question without an answer identical to this.

    Thank you!

    explain plan for

    Select * from SCOTT. DEPT;

    Don't know why you're looking for a plan in OEM.

    * Connect to the base of data with the help of sqlplus and wwho and extract the map below;

    SQL > explain plan for select * from SCOTT. DEPT;

    SQL > SELECT * FROM TABLE (dbms_xplan.display);

    * Very easy, set autotrace on and run the query, you will get the plan and statistics;

    SQL > set autotrace

    Syntax: SET AUTOT [RACE] {OFF |} WE | TRACE [ONLY]} [EXP [LAIN]] [[C] STAT]

    SQL > set autotrace on

    SQL > select * from double;

    D

    -

    X

    Execution plan

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

    Hash value of plan: 272002086

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

    | ID | Operation | Name | Lines | Bytes | Cost (% CPU). Time |

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

    |   0 | SELECT STATEMENT |      |     1.     2.     2 (0) | 00:00:01 |

    |   1.  TABLE ACCESS FULL | DOUBLE |     1.     2.     2 (0) | 00:00:01 |

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

    Statistics

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

    1 recursive calls

    0 db block Gets

    Gets 2 compatible

    0 physical reads

    0 redo size

    522 bytes sent via SQL * Net to client

    523 bytes received via SQL * Net from client

    2 SQL * Net back and forth to and from the client

    0 sorts (memory)

    0 sorts (disk)

    1 rows processed

    HTH,

    Pradeep

  • Why I have two different execution plans for the same query on two different servers

    Hello everyone.

    I need your help to solve the problem quickly.

    In a nutshell, we have two servers that have the same version of Oracle RDBMS (11.2.0.4 EE). One of them for purposes of development and another is a production one.

    We have therefore two different execution plans for the same query executed on both servers. The only case of execution is OK and another is too slow.

    So I have to slow down the work of query using the same scheme to explain that young.

    Fence wire.

  • Trace SQL execution plan

    Hello

    I need to get the execution plan for a particular SQL, but I don't have it. Application it issues for a second or two and then his party so I think that the definition of a trace on specific user. Is it possible to get the execution plan of the query like this? Thank you!

    Find the sql code, you are interested in v$ sql using the sql_text column and get the SQL_ID and CHILD_NUMBER. Entry of these two values for the query to get the execution below plan.

    Select * from table

    (dbms_xplan.display_cursor ('> ',>, 'ALLSTATS'));

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