The ultimate way to optimize SQL statements?

Similar Questions

• What is the best way to optimize a SQL query: call a function or doing a join?

  Hi, I want to know what is the best way to optimize a SQL query, call a function inside the SELECT statement, or make a simple join?

  It depends on.  Could be a.  Could be the other.  Could be no difference.  You would need to compare with your tables in your environment with your settings.

  If you put a gun to my head, I was given no other information and required that I answered the question, I would tend to wait that the join would be more effective.  In general, if you can do something in pure SQL, it will be more effective than if you call PL/SQL.

  Justin

• the number of refills for SQL statements

  Hello
  in 10g R2, how to see the number of refills for SQL statements? Any question? High value? What earned is low?
  
  Thank you.

  First run a statspack or AWR report and take a look in v$ librarycache

  Numbers are irrelevant. The reports are a little more relevant, but not necessarily a problem.

  Published by: Robert Geier on January 29, 2010 10:04

• How to use the T distribution table in sql statements?

  Hi all
  
  I'm in the need to use the T distribution table in sql... I don't know how to use...
  
  Is there a function to use the values of table in sql statements?
  
  Can someone please help me in this?

  How about this http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/functions157.htm#i1279931?

  Concerning

  Etbin

• Way to create SQL statements via sqldeveloper

  Is it possible that one can use sqldeveloper to create sql statements?
  Is the statement that I'm having a problem with: -.

  SELECT EGMGAMEVARIATIONPK FROM EGMGAMEVARIATION WHERE EGMPK=$row[0] AND STARTDATE >= TRUNC(current_date) AND (NVL(ENDATE, current_date+1) >= TRUNC(current_date))

  and even if EGMGAMEVARIATION contains a column called ENDDATE I mean: -.
  'ENDATE': identifier not valid when I run my PHP script, so I thought that if I could get the system to help me build the command I could do better.

  First, you say the name of the column is ENDDATE, yet in your query, you wrote ENDATE, then Yes, it is an invalid identifier :)
  But yes, if you like there is a Query Builder: right-click inside the SQL worksheet to invoke it.

  Have fun
  K.

• How to find the redo generated by each SQL statement?

  Database version is 10.2.0.4. OS is AIX.
  We must again excessive generation during a specific time. We want to identify what a statement contributes to excessive recovery.
  ADDM shows this as a first observation
  
  Waiting on event "log file sync" during the execution of operations of COMMIT and ROLLBACK consumed at the time of the important data.
  
  Is it possible to know which statement sql generates how many redo in bytes for a moment?
  
  Thank you
  Delphine

  Is it possible to know which statement sql generates how many redo in bytes for a moment?

  It will not help you.
  For example, you can see a lot of UPDATE, DELETE, INSERT from the apps statements. Then? What you do with them? If you can modify the application to eliminate the useless LMD - it would be great of course. But it is unlikely.

  When the DML statements also generate Redo, does not cause them too much expectations "log file sync", because the writer log buffer empty buffer as soon as it fulfills more than 30% after a certain time or on Commit / Rollback.

  Waiting on event "log file sync" during the execution of operations of COMMIT and ROLLBACK consumed at the time of the important data.

  Right. This is because the writer written newspaper here synchronous, reliable, he waits until the HDD writes data down and meets its written OK.
  And hard drives are not the fastest things in the computer. They are mechanical - that's why.

  I would recommend:
  1. place files redo log on quick drives used preference dedicated only to this end. If other I/O will often disturb these readers resulting securities heads change causing longer HDD expected.
  2 consider using faster technology such as SAN or SSD.

• How to add the number of the column by another county sql statement

  My problem is

  SELECT Count (DISTINCT num) OF tmp_table;

  the foregoing will return 13.

  
  

  UPDATE seq_table a SET a.currentvalue = a.currentvalue + 1 + (SELECT Count(DISTINCT num) FROM tmp_table;)  WHERE a.seq_type LIKE 'ABC% ';

  the result of updating should be = a.currentvalue + 1 + 13

  How is that possible? There is syntax error...

  Not sure if this was clear ;-), but there's a semicolon behind tmp_table and SQL does not understand that.

  Then

  UPDATE seq_table SET a.currentvalue = a.currentvalue + 1 + (SELECT Count(DISTINCT num) FROM tmp_table) WHERE a.seq_type LIKE 'ABC% ';

• HP Pavilion - the best way to optimize?

  SYSTEM INFORMATION: Pavilion PU131AV / a1050y, Windows XP SP3 32-bit, Nvidia GeForce 6600, MCE, Intel Pentium 4 CPU 3.20 GHz, 2 GB RAM

  PROBLEM: Office seems to have problems running the basic operations.  For example:

  a. when copying large amounts of data (50 + GB) to one external hardrive to another (via USB), Pavilion will restart.  This was never the case before.  Was able to perform the same task via my laptop Presario (AMD Turion 64 Mobile Technology ML-32, 1.79 GHz, 384 MB RAM) with no problem and effectively transferred to 150 GB of info with the cell value.

  b. it took an hour and a half to format an external hard drive 300 GB (via USB) with the Pavilion.  It took only 5 minutes to format an external hard drive 200 GB (via USB) with the Presario.

  c. when downloading 4 GB with a value of the info of a DVD on the Pavilion, the computer will restart.

  QUESTION: What can I do to ensure that my flag is optimized?  How can I solve these issues the best?

  Thank you very much

  Angela

  ``````````````````````````````````````````
  old computer: HP Pavilion PU131AV / a1050y, Intel Pentium 4 CPU 3.20 GHz, 2 GB RAM, Windows XP MCE, SP3 32-bit, Nvidia GeForce 6600
  new computer: HPE-180 t, Windows 7 Pro (64 bit), Nvidia GeForce GT 220, Intel Core i7 - 930 quad-core CPU @ 2.80 GHz, 8 GB of RAM

  TX, looks like it's time to use some of these new tools for backup and perform a destructive system recovery.  Computers access naturally more slow times of installing and uninstalling the programs.  The registry have assign traces remaining.  The problem is, most of the registry cleaners, cause more problems than they solve.  Thus, a good recovery system solves this problem.

• The analysis of a sql statement without executing it

  Hello everyone,
  
  I would like to know a way of parsing sql statements to validate them, so I would get the error messages in advance without executing them.
  
  Here we have the difficult task to analyze several sql scripts and send corrections to the development team and thirty third companies before applying them in our production databases. I am ready to create a program web/pl sql, making this difficult task, at least one program to identify errors such as lack of owner of the table, nonexistent tables, syntax errors and so on...
  
  Any information will be a great help!
  
  Thanks in advance.

  Hi and welcome to the forum.

  Tip1:
  http://asktom.Oracle.com/pls/asktom/f?p=100:11:0:P11_QUESTION_ID:3648254441315

  Tip2:
  to bookmark this forum (SQL and PL/SQL)
  Bookmark http://tahiti.oracle.com (The Oracle Documentation)
  Bookmark http://asktom.oracle.com

  Tip3:
  On all the sites mentioned, you can do a quick search on key words of your interest and you will get the examples and explanations returned.

• I need help in the sql statement

  Hi all
  im working in the hr schema
  I need sql statement to answer my question
  I need information to all employees
  where average wage = average wage department 50
  Sorry I can't speak English very well
  I thank all

  There is no need to do so in the two motions. All you need is:

  select  *
    from  (
           select  e.*,
                   avg(case department_id when 50 then salary end) over() dept_50_avg_sal
             from  hr.employees e
          )
    where salary <= dept_50_avg_sal
  / 
  
  EMPLOYEE_ID FIRST_NAME           LAST_NAME                 EMAIL                     PHONE_NUMBER         HIRE_DATE JOB_ID         SALARY COMMISSION_PCT MANAGER_ID DEPARTMENT_ID DEPT_50_AVG_SAL
  ----------- -------------------- ------------------------- ------------------------- -------------------- --------- ---------- ---------- -------------- ---------- ------------- ---------------
          198 Donald               OConnell                  DOCONNEL                  650.507.9833         21-JUN-07 SH_CLERK         2600                       124            50      3475.55556
          199 Douglas              Grant                     DGRANT                    650.507.9844         13-JAN-08 SH_CLERK         2600                       124            50      3475.55556
          115 Alexander            Khoo                      AKHOO                     515.127.4562         18-MAY-03 PU_CLERK         3100                       114            30      3475.55556
          116 Shelli               Baida                     SBAIDA                    515.127.4563         24-DEC-05 PU_CLERK         2900                       114            30      3475.55556
          117 Sigal                Tobias                    STOBIAS                   515.127.4564         24-JUL-05 PU_CLERK         2800                       114            30      3475.55556
          118 Guy                  Himuro                    GHIMURO                   515.127.4565         15-NOV-06 PU_CLERK         2600                       114            30      3475.55556
          119 Karen                Colmenares                KCOLMENA                  515.127.4566         10-AUG-07 PU_CLERK         2500                       114            30      3475.55556
          125 Julia                Nayer                     JNAYER                    650.124.1214         16-JUL-05 ST_CLERK         3200                       120            50      3475.55556
          126 Irene                Mikkilineni               IMIKKILI                  650.124.1224         28-SEP-06 ST_CLERK         2700                       120            50      3475.55556
          127 James                Landry                    JLANDRY                   650.124.1334         14-JAN-07 ST_CLERK         2400                       120            50      3475.55556
          128 Steven               Markle                    SMARKLE                   650.124.1434         08-MAR-08 ST_CLERK         2200                       120            50      3475.55556
  
  EMPLOYEE_ID FIRST_NAME           LAST_NAME                 EMAIL                     PHONE_NUMBER         HIRE_DATE JOB_ID         SALARY COMMISSION_PCT MANAGER_ID DEPARTMENT_ID DEPT_50_AVG_SAL
  ----------- -------------------- ------------------------- ------------------------- -------------------- --------- ---------- ---------- -------------- ---------- ------------- ---------------
          129 Laura                Bissot                    LBISSOT                   650.124.5234         20-AUG-05 ST_CLERK         3300                       121            50      3475.55556
          130 Mozhe                Atkinson                  MATKINSO                  650.124.6234         30-OCT-05 ST_CLERK         2800                       121            50      3475.55556
          131 James                Marlow                    JAMRLOW                   650.124.7234         16-FEB-05 ST_CLERK         2500                       121            50      3475.55556
          132 TJ                   Olson                     TJOLSON                   650.124.8234         10-APR-07 ST_CLERK         2100                       121            50      3475.55556
          133 Jason                Mallin                    JMALLIN                   650.127.1934         14-JUN-04 ST_CLERK         3300                       122            50      3475.55556
          134 Michael              Rogers                    MROGERS                   650.127.1834         26-AUG-06 ST_CLERK         2900                       122            50      3475.55556
          135 Ki                   Gee                       KGEE                      650.127.1734         12-DEC-07 ST_CLERK         2400                       122            50      3475.55556
          136 Hazel                Philtanker                HPHILTAN                  650.127.1634         06-FEB-08 ST_CLERK         2200                       122            50      3475.55556
          138 Stephen              Stiles                    SSTILES                   650.121.2034         26-OCT-05 ST_CLERK         3200                       123            50      3475.55556
          139 John                 Seo                       JSEO                      650.121.2019         12-FEB-06 ST_CLERK         2700                       123            50      3475.55556
          140 Joshua               Patel                     JPATEL                    650.121.1834         06-APR-06 ST_CLERK         2500                       123            50      3475.55556
  
  EMPLOYEE_ID FIRST_NAME           LAST_NAME                 EMAIL                     PHONE_NUMBER         HIRE_DATE JOB_ID         SALARY COMMISSION_PCT MANAGER_ID DEPARTMENT_ID DEPT_50_AVG_SAL
  ----------- -------------------- ------------------------- ------------------------- -------------------- --------- ---------- ---------- -------------- ---------- ------------- ---------------
          142 Curtis               Davies                    CDAVIES                   650.121.2994         29-JAN-05 ST_CLERK         3100                       124            50      3475.55556
          143 Randall              Matos                     RMATOS                    650.121.2874         15-MAR-06 ST_CLERK         2600                       124            50      3475.55556
          144 Peter                Vargas                    PVARGAS                   650.121.2004         09-JUL-06 ST_CLERK         2500                       124            50      3475.55556
          180 Winston              Taylor                    WTAYLOR                   650.507.9876         24-JAN-06 SH_CLERK         3200                       120            50      3475.55556
          181 Jean                 Fleaur                    JFLEAUR                   650.507.9877         23-FEB-06 SH_CLERK         3100                       120            50      3475.55556
          182 Martha               Sullivan                  MSULLIVA                  650.507.9878         21-JUN-07 SH_CLERK         2500                       120            50      3475.55556
          183 Girard               Geoni                     GGEONI                    650.507.9879         03-FEB-08 SH_CLERK         2800                       120            50      3475.55556
          186 Julia                Dellinger                 JDELLING                  650.509.3876         24-JUN-06 SH_CLERK         3400                       121            50      3475.55556
          187 Anthony              Cabrio                    ACABRIO                   650.509.4876         07-FEB-07 SH_CLERK         3000                       121            50      3475.55556
          190 Timothy              Gates                     TGATES                    650.505.3876         11-JUL-06 SH_CLERK         2900                       122            50      3475.55556
          191 Randall              Perkins                   RPERKINS                  650.505.4876         19-DEC-07 SH_CLERK         2500                       122            50      3475.55556
  
  EMPLOYEE_ID FIRST_NAME           LAST_NAME                 EMAIL                     PHONE_NUMBER         HIRE_DATE JOB_ID         SALARY COMMISSION_PCT MANAGER_ID DEPARTMENT_ID DEPT_50_AVG_SAL
  ----------- -------------------- ------------------------- ------------------------- -------------------- --------- ---------- ---------- -------------- ---------- ------------- ---------------
          194 Samuel               McCain                    SMCCAIN                   650.501.3876         01-JUL-06 SH_CLERK         3200                       123            50      3475.55556
          195 Vance                Jones                     VJONES                    650.501.4876         17-MAR-07 SH_CLERK         2800                       123            50      3475.55556
          196 Alana                Walsh                     AWALSH                    650.507.9811         24-APR-06 SH_CLERK         3100                       124            50      3475.55556
          197 Kevin                Feeney                    KFEENEY                   650.507.9822         23-MAY-06 SH_CLERK         3000                       124            50      3475.55556
  
  37 rows selected.
  
  SQL> 
  

  SY.

• The sense of time in sql

  Hi all
  
  A simple matter of time spent in v$ sql.
  
  I know that this means that a total duration when a query runs.
  
  I think that
  
  time elapsed time = cpu + user + application_wait_time o wait times
  + concurrency_wait_time + cluster_wait_time + plsql_exec_time + java_exec_time
  
  of course, the passage of time could not be exactly the same with a sum of above things, because its value is the cumulative value.
  
  but I have a few weird data. its value is 130% of the amount. I have no idea whence the other 30%.
  
  its value is too big to ignore.
  
  does anyone have an idea?
  
  (this is a kernel environment)
  
  Thanks in advance...

  Hello
  If you draw the session (10046) an application, following will be the result in the file path for each SQL statement

  SELECT "COSTCODE","INSERTDATETIME","LOTID","SOURCELOTID","STAGE","SUPPLIERID"
  FROM
   "ACTL_PARTINFO_CUST" "A" WHERE "SUPPLIERID"='RD1' AND "INSERTDATETIME"=
    TO_DATE('2010-08-18 07:05:00', 'yyyy-mm-dd hh24:mi:ss') AND "STAGE"=:1 AND
    "LOTID" LIKE 'C%' AND "COSTCODE"='A' AND "SOURCELOTID" LIKE 'F%'
  
  call     count       cpu    elapsed       disk      query    current        rows
  ------- ------  -------- ---------- ---------- ---------- ----------  ----------
  Parse        1      0.00       0.00          0          0          0           0
  Execute 300372      3.27      69.85          0          0          0           0
  Fetch   300371   1916.42    6551.42          0  100023544          0           0
  ------- ------  -------- ---------- ---------- ---------- ----------  ----------
  total   600744   1919.69    6621.27          0  100023544          0           0
  
  Misses in library cache during parse: 0
  Optimizer mode: ALL_ROWS
  Parsing user id: 61  (DWDB_REPORTING)
  
  Elapsed times include waiting on following events:
    Event waited on                             Times   Max. Wait  Total Waited
    ----------------------------------------   Waited  ----------  ------------
    SQL*Net message to client                  300371        0.02          0.64
    SQL*Net message from client                300371        5.33       4860.35
    latch: cache buffers chains                  7199        0.38         49.62
    latch free                                     99        0.04          0.72
    latch: enqueue hash chains                      5        0.03          0.07
  

  Here you can see the total elapsed time next to the database including waiting events.

  Salman

• The temporary and tables using SQL tuning tools

  The application that I support uses temporary tables for the majority of queries... Looking at the SQL tuning advisor and more of other oracle tuning tools, they seem well managing temporary tables.
  
  It's what Happens (from what I can tell).
  
  (1) oracle identifies a SQL statement (or the ADMINISTRATOR only), to be tuned.
  (2) the original execution statistics are saved for comparison
  (3) oracle tries to find a new plan (but at this point, the temporary table is empty).
  (4) it tries to execute the new plan (once again the temporary table is empty).
  (5) it comparies the execution time of the new plan against the original plan
  
  The comparison, of course, is not a reasonable comparison.
  
  Does anyone have experience with this problem? My first thought is for 'premium' of the temporary table, then run the Advisor of tuning in the same session (hoping that it will use the values in the temporary table).
  
  Other than that, rereading of the database seems to be the best way to adjust sql plan changes using baselines.

  Expected.

• 00900 invalid SQL statement error

  I am myself to write stored procedures, teacher in TOAD 10.5 with Oracle 10 g. I get the error ORA-00900: invalid SQL statement. Here's the code, cut to the minimum sample size strip. I don't see where I'm doing something wrong.
  
  If I cut out the slider (take it down to just "Begin" and "End"), it runs, but I don't see anything wrong with the cursor.
  
  Any ideas?
  
  CREATE OR REPLACE PROCEDURE IN_PROCESS_CASES_BOS
  IS
  V_HELLO VARCHAR2 (10);
  
  CURSOR C_MAIN IS
  SELECT 'HELLO' FROM DUAL;
  
  BEGIN
  
  C_MAIN OPEN;
  
  LOOP
  EXTRACT THE C_MAIN IN V_HELLO;
  
  WHEN THE OUTPUT C_MAIN % NOTFOUND;
  
  END LOOP;
  
  CLOSE C_MAIN;
  END;
  END IN_PROCESS_CASES_BOS;
  /

  select * from user_errors;
  
  NAME                           TYPE           SEQUENCE       LINE   POSITION
  ------------------------------ ------------ ---------- ---------- ----------
  TEXT
  --------------------------------------------------------------------------------
  ATTRIBUTE MESSAGE_NUMBER
  --------- --------------
  IN_PROCESS_CASES_BOS           PROCEDURE             1         21          1
  PLS-00103: Encountered the symbol "END"
  ERROR                103
  

  You have an extra END; Remove it and the procedure compiles and runs.

• How to concatenate two sql statements?

  Hello
  
  How can I combine the following two sql statements so that the result of a line of the first statement appears before the lines of my second sql statement. The reason I need it is to order the lines correctly.
  
  Select the username, id
  some abusers
  where id = 0
  
  Select the username, id
  some abusers
  where id! = 0
  order by username
  
  Thank you
  j

  You should ask in the forum of the Apex:
  Oracle Application Express (APEX)

  Nicolas.

• problem when creating a trigger: SQL statement ignored

  Hello people,
  
  I am trying to create a trigger, but it is not created. Instead, I get the error message that a SQL statement at line 22 was ignored. It's the line indicating IF num2 = 1 THEN. I'd be happy if someone could point me in the right direction or solve my problem.
  
  CREATE OR REPLACE TRIGGER TriggerLogement BEFORE INSERT OR update ON tenants
  FOR EACH LINE
  DECLARE
  NUM INTEGER;
  num2 INTEGER;
  NUM3 INTEGER;
  paysLocataire VARCHAR2 (255);
  categorieLocataire VARCHAR2 (1);
  BEGIN
  SELECT COUNT (ns) IN the number OF tenants WHERE nomBat =: new.nomBat;
  
  IF num > 0 THEN
  SELECT paid IN the country OF sports WHERE ns =: new.ns;
  SELECT COUNT (country) IN number OF athletes sp, tenants lo WHERE sp.ns = lo.ns AND paysLocataire AND lo.nomBat = pays =: new.nomBat;
  IF num = 0 THEN
  raise_application_error (-20000, "building already in use for another nationality");
  ON THE OTHER
  SELECT COUNT (ns) IN num2 OF tenants WHERE nLogement =: new. NLogement AND nomBat =: new.nomBat;
  IF num2 = 2 THEN
  raise_application_error (-20000, 'full accommodation');
  ON THE OTHER
  IF num2 = 1 THEN
  CateogrieLocataire INTO SELECT category OF athletes WHERE ns = new.ns;
  SELECT COUNT (ns) IN num3 FROM tenant lo, sportsmen sp WHERE lo.ns = sp.ns
  AND lo.nLogement =: new. NLogement AND lo.nomBat =: new.nomBat AND sp.categorie = categorieLocataire;
  IF num3 = 0 THEN
  raise_application_error ("-20000, ' already in use for the other sex");
  END IF;
  END IF;
  END IF;
  END IF;
  END IF;
  END;
  
  If you need more information or if you have any questions about my posts please leave your questions or comments. I hope this isn't how completely wrong to enforce some constraints that I can't do with CONSTRAINT and CHECK in the schema definition.
  
  Thanks for your help and your attention.
  
  Sebastian

  Hello

  Whenever you have a problem that raises an error, display the full error message; do not paraphrase just part of it.

  In the triggers line numbers from the first statement DECLARE or BEGIN, so line 22 of your trigger is:

  SELECT categorie INTO cateogrieLocataire FROM Sportifs WHERE ns = new.ns;
  

  You are missing a colon before 'new': it should be:

  SELECT categorie INTO cateogrieLocataire FROM Sportifs WHERE ns = :new.ns;
  

  A FOR EACH ROW trigger on tenants cannot ask tenants. It's a shame: there are many useful things, you could do if that were allowed, but it's not.
  I'm not sure of what all queries. At least one of them:

  SELECT  COUNT (ns)
  INTO    num2
  FROM    Locataires
  WHERE   nLogement = :new.NLogement
  AND     nomBat    = :new.nomBat;
  
  IF num2 = 2 THEN
      raise_application_error(-20000,'accomodation full');
  

  can be replaced by a UNIQUE constraint. (Constraints are better than triggers, in any case.)

  If you can't do what you want with constraints, you can leave anyone directly INSERT or update the table: force them to use a procedure stored instead. You can have an INSTEAD OF trigger on a view, which is essentially the same, but allows you to use DML commands.

  If you need help, post some sample data and some examples of DML operations that must be allowed, given the data and some examples of DML operations that should not be allowed.