Odd variance in query execution time

Similar Questions

• How to get the query execution time without running...?

  Hello
  
  I had one condition... as follows...
  I had 3 sql statements. I need to run only sql what runtime is very less.
  
  Can someone help me, how to get the time query and run this query without using explain plan... ?
  
  Thank you
  Rajesh

  I can't think in any way at all to get the query execution time without running the query.

  You might get an estimate ( approximation ) If you are using explain plan.

  But you have governed to explain plan for a reason, so I can't help you.
  Why you do not want to use don't explain plan?

• Reg: SQL query execution time

  Hi all
  
  How to identify the oracle sql query execution time.
  
  Thanks in advance.

  SQL> set timing on
  

• Query execution time

  Hello

  Maybe a stupid question, but I would like to know if it is possible to calculate the execution time of a query.

  I know ' set timing on ', but I can't use it, because I don't have any environment for the needs of the school project.

  I have to select all the orders for a line in a table with more than 1,000,000 records (easy ^^) and there are 100 users simultaneously connected.

  How long is the execution time and the impact of 100 users (Oracle 11 g)?

  Of course, it also depends on the server, the table index, etc., but this should be ignored.

  Maybe somebody has a tip or a white paper?

  Thank you

  It depends on the code that you are proposing.

  If you are using bind variables and/or analyze only once, your application is scalable and the number of users is not serious.

  As part of the memory is to be locked during analysis, analysis each time or do not use do not bind variable, your application allows serialize access to the database, and the amount of resources will be directly dependent on the number of users. In doing so, your app is impassable.

  The number of users will now be certainly serious.

  ----------

  Sybrand Bakker

  Senior Oracle DBA

• Query execution times increase when reruns after 10 minutes

  We strive to optimize the query (SELECT statement of the USERS table) below. On the first run time, 47ms and on the next run, it takes averagely about 5ms. If I run it again after 10 minutes, then same 47ms on average.

  This means that I need to increase the size of the SGA to hold the query/blocks here for a long time. The USERS table is a small table containing about 500 lines. Here are the General settings. The machine is not used actively, because this is a dev database.

  SGA_MAX_SIZE = 325 MB

  SGA_TARGET = 325 MB

  Query:

  DECLARE
     v_id   number;
     v_user varchar2(100);
     v_password varchar2(1000);
     v_description varchar2(100);
     v_active char(1);
     v_update_time date;
     
     start_time   TIMESTAMP;
     end_time   TIMESTAMP;
  BEGIN
     start_time := SYSTIMESTAMP;
  
  
     SELECT ID, name, password,description,active, update_time
       INTO v_id, v_user, v_password,v_description,v_active, v_update_time
       FROM USERS
      WHERE user_name = 'userName2';
     end_time := SYSTIMESTAMP;
  DBMS_OUTPUT.PUT_LINE ( (EXTRACT (SECOND FROM end_time) - EXTRACT (SECOND FROM start_time)) * 1000);
  END;
  /
  

  We use the Oracle 10 g R2 with Linux.

  Oh sorry you have defined sga_target then it means that you use Automatic Shared Memory Management. If you use a 10.x database I guess.

  The buffer cache works in FIFO basis. So when you run the same query after 10 minutes the data block is not available in the buffer cache, if oracle is physical i/o.

  And as you mentioned that you are working on a DEV database is it possible that someone else is populating the buffer cache which may not be the case in the PROD?

  There is no rule defining the size of the SGA. You will need to constantly work on it to keep your optimum performance. But at the same time, you also need to consider the available memory. You may not use all of them for yourself.

  So the bottom line is based on the available memory and your condition of database, you can try to adjust the size of the SGA. But do it in a DEV box (which I suppose is not as close as a PROD box) cannot be successful.

• How to know the execution time of query in sql plus

  Hello
  
  I want to know the duration of execution of query in sql more accompanied by statistics
  
  I say time is set on;
  Set autotrace on;
  Select * view where usr_id = "abcd";
  
  
  If the result is 300 lines it scrolls up until all the rows are retrieved and finally gives me the run time in 40 seconds, or 1 minute... (it is after all records scrolls)
  
  but when I run it in Toad he gives 350 milli seconds...
  
  I want to see the execution time in sql how to proceed
  
  client and database server 11g is g 10
  
  concerning
  REDA

  In sqlplus you can do set autotrace traces to suppress the display of the selected lines.

  John

• Questions HFR - "5200: query execution error: invalid item ID".

  Hi all

  We use the Hyperion HFM 11.1.1.3 application. We have recently upgraded to the Oralce Database 11.2.0.2 and reconfigured the HFM application with this new version of the database. When I tried to run the Financial reporting via the HFR studio, I get the error message - ' 5200: query execution error: invalid item ID ". Please could you help me solve this problem.

  Thank you

  Michel K

  It was because of the default angle that is invalid for the user which was inconsistent with the special report.

  Change the preferences to the preview from the user Point of view and rerun the report.

  File > preference > Financial Reporting > preview select 'ON' box under the Point of view.

  Re-run the report, then select the desired POV.

  This will prompt the user to change their POV every time that he or she opens a report. They can select the correct POV and the report runs successfully.

  You can turn off later. Let me know if it solved that problem.

• Calculation actual and average execution time

  Hi guru,.

  I have a scenario where I connect my moment of execution in a Table, and my batch

  
  

  Batch_id Scenario_Name

  1 Scen1

  1 Scen2

  1 Scen3

  2 Scen1

  2 Scen2

  2 Scen3

  3 Scen1

  3 Scen2

  3 Scen3

  Now my question is I want to calculate the duration of actual execution and the execution time of the Avg, while Avg running time calculation, I current Batch_ID to exclusion of

  Select scenario_name, count (scenario_name).

  sum (MOD (FLOOR ((END_DATE-START_DATE) * 24 * 60 * 60), 60)) Total.

  sum (MOD (FLOOR ((date_fin-START_DATE) * 24 * 60 * 60), 60)) count (scenario_name) Avg

  of Execution_Log

  -where batch_id = 1

  Scenario_name group

  This query will give me the result, but it's also including current Batch_Id

  OK, try this query. I dropped the group by clause as the avg is the only present aggregation, and who is now handled through the analytical counterpart (with more partition by clause).

  SELECT

  A.BATCH_ID,

  A.SCENARIO_NO,

  A.SCENARIO_NAME,

  C.TGT_TABLE_NAME,

  A.START_DATE,

  A.END_DATE,

  A.EXECUTION_STATUS,

  Decode(A.EXECUTION_STATUS,'COMPLETED','No Error','FAILED',A.ERROR_MESSAGE,null) ERROR_MESSAGE

  MOD (G ((A.END_DATE-A.)) START_DATE) * 24 * 60 * 60), 60) TEMPS_REEL.

  AVG (MOD (FLOOR ((A.END_DATE-A.START_DATE) * 24 * 60 * 60), 60)) on (A.scenario_name partition) AVG_TIME

  To exec_log1 A

  INNER JOIN exec_log2 B

  ON A.BATCH_ID = B.BATCH_ID

  AND A.BATCH_ID = 2

  INNER exec_log3 C

  ON A.SCENARIO_NO = C.SCENARIO_NO

  AND A.SCENARIO_NAME = C.SCENARIO_NAME

  ORDER BY A.SCENARIO_NAME ASC

  I hope this helps.

• How to know the execution time

  Hello
  
  I'm using Oracle 11 g. I want to know the execution time of a query.
  
  Can someone help me please how to find it.
  
  And. y at - it a tool that compares the performance of the 2 queries?

  user13044793 wrote:
  Hello

  I'm using Oracle 11 g. I want to know the execution time of a query.

  Can someone help me please how to find it.

  In SQL * more:

  SET TIMING ON

  And. y at - it a tool that compares the performance of the 2 queries?

  In SQL * more:

  SET AUTOTRACE ON

  URS

• Resource plan in order to limit the execution time

  Hello
  I use 11.1.0.7 database. Can someone guide me how can I create a resource group resource consumers plan and assign them to my user "dev" so that any query that is run by this user shouldn't take more than 10 minutes for execution and must be abandoned if the execution time exceeds 10 minutes.
  
  Thank you
  
  Salman

  BEGIN
  dbms_resource_manager.clear_pending_area();
  dbms_resource_manager.create_pending_area();
  dbms_resource_manager.create_consumer_group(consumer_group => 'mytest_group', comment => '', cpu_mth => 'ROUND-ROBIN');
  dbms_resource_manager.submit_pending_area();
  END;
  
  BEGIN
  dbms_resource_manager.clear_pending_area();
  dbms_resource_manager.create_pending_area();
  dbms_resource_manager.create_plan( 'MYTEST_PLAN', '');
  dbms_resource_manager.create_plan_directive(
      plan => 'MYTEST_PLAN',
      group_or_subplan => 'MYTEST_GROUP',
      comment => '',
      cpu_p1 => NULL, cpu_p2 => NULL, cpu_p3 => NULL, cpu_p4 => NULL,
      cpu_p5 => NULL, cpu_p6 => NULL, cpu_p7 => NULL, cpu_p8 => NULL,
      parallel_degree_limit_p1 => NULL,
      active_sess_pool_p1 => NULL,
      queueing_p1 => NULL,
      switch_group => 'KILL_SESSION',
      switch_time => 600,
      switch_estimate => false,
      max_est_exec_time => NULL,
      undo_pool => NULL,
      max_idle_time => NULL,
      max_idle_blocker_time => NULL,
      switch_time_in_call => NULL
  );
  dbms_resource_manager.create_plan_directive(
      plan => 'MYTEST_PLAN',
      group_or_subplan => 'OTHER_GROUPS',
      comment => '',
      cpu_p1 => NULL, cpu_p2 => NULL, cpu_p3 => NULL, cpu_p4 => NULL,
      cpu_p5 => NULL, cpu_p6 => NULL, cpu_p7 => NULL, cpu_p8 => NULL,
      parallel_degree_limit_p1 => NULL,
      active_sess_pool_p1 => NULL,
      queueing_p1 => NULL,
      switch_group => NULL,
      switch_time => NULL,
      switch_estimate => false,
      max_est_exec_time => NULL,
      undo_pool => NULL,
      max_idle_time => NULL,
      max_idle_blocker_time => NULL,
      switch_time_in_call => NULL
  );
  dbms_resource_manager.submit_pending_area();
  END;
  
  BEGIN
  dbms_resource_manager.clear_pending_area();
  dbms_resource_manager.create_pending_area();
  dbms_resource_manager.set_consumer_group_mapping(
      dbms_resource_manager.oracle_user,
      'DEV',
      'MYTEST_GROUP'
  );
  dbms_resource_manager.submit_pending_area();
  END;
  

• How to shorten the execution time of the NXT (TETRIX & MATRIX toolkit) brick

  Hello

  How to shorten the execution time of the NXT brick?

  (TETRIX & MATRIX toolkit, running time)

  The software is 2012 LabVIEW for LEGO MINDSTORMS

  Thank you.

  

  

  Hi 40123157,

  You use the module in an appropriate manner, and there is no simple way to improve the time of loop iteration beyond what you've done. Here are my suggestions:

  (1) the i2c commands take a long time. In your application, it may speed up if you run only move the engine only when the engine speed has changed.

  (2) for this particular example, you do not use the release of the report engine. If this VI does not need to run it can be removed.

  (3) If you need to speed up execution other than that, as a user advanced LabVIEW, you can create a copy of the VI of engines to move and change it as you choose. All you have to to the "DC motors' entry is use cluster to array on the cluster, as shown below. I think you can speed it up by running all the settings before the loop (type sensor and fixed connection configuration), and removing the value of power if you send only the values between-100 and 100.

  (4) drawing on the screen can be slow you down here.

  

• How to calculate the execution time of a SCTL in FPGA VI?

  Hello

  Can someone guide me that how to calculate the execution time of a SCTL for an iteration in the FPGA VI?

  Thank you and best regards,

  Rashid

  Hello r,.

  A SCTL will always run in a beat the clock it has been linked to.  So, if you use a 40 MHz clock, this loop will run in 25 ns.  If the code cannot complete in that, or if it requires two graduations of the watch to do the calculation, your code does not compile, then you have the guarantee that this will always be how long it takes this piece of code to run.

• How to measure the execution time of a specific to a VI process?

  Hello! My VI has two processes: compression and edge detection image and I'm trying to measure the execution time for the process of detection of edge of my VI, but I don't know how to do. Please give me some ideas on how to do it. Thank you!

  There are several ways that you can do.

  -L' one is using the number of cycles before and after your vi to get time like here: http://digital.ni.com/public.nsf/allkb/6F6B9F4E149C80578625652800784764

  - or use the profiling: https://zone.ni.com/reference/en-XX/help/371361H-01/lvhowto/profiling_vis/

  Edit: If you're open to suggestions:

  -You have not to load the image inside the loop instead, make him outside of the loop.

  - And I see of many IMAQ buffers are not removed properly. You can have everything at once by Images (No) by logging in to Boolean TRUE: http://zone.ni.com/reference/en-XX/help/370281P-01/imaqvision/imaq_dispose/

• How to calculate the execution time of a loop?

  Hello

  Can someone guide me that how to calculate the execution time of a loop to iterate?

  Thank you and best regards,

  Rashid

  I hope I have your question! See attached screenshot

• too low execution time

  I tried to measure the execution time. The rate is 1KS/s through to read 100 per channel in a loop of 10 and samples. The time should be about 1000 ms, but it is only 500-600 ms. And when I changed the rate/number of samples, the run time does not change... How could it happen?

  Well,.

  The task inside the loop compensation is something of a problem.  (The error handler must jump on the second iteration)