Order in where clause - SQL statement

Hi,
The order of the fields in Where clause in OpenSQL statements is important to get the right index?
Select a b c from t1
where
d = p_d and
e = p_e
Or
Select a b c from t1
where
e = p_e and
d = p_d
Index:
columns e and d.
Thanks !

HI,
Both will give you the same result.. but it is always good to pass the sequence as in the table.. the performance will be good when you follow the sequece of occurance of the fields.
Thanks
Mahesh

Similar Messages

SQL: order of WHERE clauses important for performance?

I wonder if the order of the WHERE clauses does affect performance or if the database optimize each query so that the order is irrelevant? Example: is
SELECT *
FROM Table1
WHERE (fast condition check)
AND (slow condition check)
faster than
SELECT *
FROM Table1
WHERE (slow condition check)
AND (fast condition check)
because the first condition check might be false and therefore the second is not executed? (Some kind of Java if (fast && slow) is faster than if (slow && fast) ?)

It depends on how sophisticated the database optimizer is. IBM's DB2/UDB will completely rewrite the syntax of SQL as part of optimization and does not care what the order of the where clause is. Oracle actually has two optimizers RULE and COST. The RULE based optimizer is affected by the order of the where clause, COST is not (RULE is no longer available in the newest version of Oracle, Oracle 10g).

Sql order in where clause...

i want to ask about
how oracle deal with the order of where cluase
as in select * from where tname = 'EMP'
and tabtype = 'TABLE'
oracle strat from down (tabtype) or from up (tname)
and there is difference between this order
if the where clause contains (and) or (or)
i always need to know this thing but no place i found say about it in strait way..
thanks..
null

I am sorry for the late reply.
I guess that ORDER doesn't matter in the WHERE clause. We should take 2 cases:
1) Say, in a WHERE clause, U have a limiting condition on one of the indexed field of the table, then definitely that will be executed first and the result set will be passed to the other conditions.
2) Say, in the WHERE clause, U don't have any indexed field then ORACLE will go for cost based execution. In this case, it will first go to the column, for which the SELECTIVITY is the highest ( ORACLE does so internally ) and then the result set is passed to the other conditions.
Hope this helps.
Correct me, if I am wrong.

Define a Standalone Download Integrator with an Additional Where clause - SQL error

Hi,
I am trying to create a standalone integrator with an Additional Where clause. Followed the steps mentioned in the metalink note 360105.1. When I run the integrator, I get the following error message.
Please resolve the following error to continue.
SQL error: ORA-00936: missing expression occurred
processing stored SQL for Content 20007:GENERAL_441_CNT.
When I look at the log file, here is what I can see:
10/22/14 10:50 AM AJPRequestHandler-HTTPThreadGroup-15 TRACE          BneHrSQLControl - SQL:SELECT FROM PER_PEOPLE_V where last_name=$PARAM$.last_name
10/22/14 10:50 AM AJPRequestHandler-HTTPThreadGroup-15 TRACE          validateSQLStatement value of sqlStatement is: SELECT FROM PER_PEOPLE_V where last_name=:RSQLP1
10/22/14 10:50 AM AJPRequestHandler-HTTPThreadGroup-15 DETAIL         BneHrSQLControl.validateSQLStatement() paramName: last_name
10/22/14 10:50 AM AJPRequestHandler-HTTPThreadGroup-15 DETAIL         BneHrSQLControl.validateSQLStatement() error in SQL: java.sql.SQLSyntaxErrorException: ORA-00936: missing expression
So, clearly, the SQL statement that is getting built internally is wrong. Ideally, I would expect the statement to be something like this:
SELECT * FROM PER_PEOPLE_V where last_name=$PARAM$.last_name.
RDBMS : 11.2.0.3.0
Oracle Applications : 12.1.3
Any pointers towards the resolution of the issue would be of great help.
Thanks in Advance!
Lalitha.

This is a duplicate post of your other question: create trigger automatic
DO NOT start duplicate threads for the same question.
Locking this thread

Where Clause SQL Loader

Hi,
Please could someone give me the syntax for expressing a where clause in SQL Loader control file? as an example i only want the data in the columns to be uploaded where person_id matches the person_id already present in the table.
My control file is below which needs amending to include a 'Where'. The append will also need changing i assume.
load data
infile '/app/DEV/appl/xxcpp/11.5.0/bin/TEST.csv'
APPEND
into table XXCPP_SQL_LOADER_TEST
fields terminated by "," optionally enclosed by '"'
( PERSON_ID, EMP_NAME, EMP_NUMBER, START_DATE DATE "fmDD/MM/RRRR" )
Many Thanks

SQL*Loader has very limited conditional load capabilities. WHEN clause does not support OR (and it is documented). Anyway, you could do the following. Control file:
load data
infile *
APPEND
into table XXCPP_SQL_LOADER_TEST
When Person_id = '1'
fields terminated by "," optionally enclosed by '"'
( PERSON_ID POSITION(1), EMP_NAME, EMP_NUMBER, START_DATE DATE "fmDD/MM/RRRR" )
into table XXCPP_SQL_LOADER_TEST
When Person_id = '2'
fields terminated by "," optionally enclosed by '"'
( PERSON_ID POSITION(1), EMP_NAME, EMP_NUMBER, START_DATE DATE "fmDD/MM/RRRR" )
into table XXCPP_SQL_LOADER_TEST
When Person_id = '3'
fields terminated by "," optionally enclosed by '"'
( PERSON_ID POSITION(1), EMP_NAME, EMP_NUMBER, START_DATE DATE "fmDD/MM/RRRR" )
begindata
1,A,11,13/01/2011
2,B,12,13/01/2011
3,C,13,13/01/2011
4,D,14,13/01/2011
5,D,15,13/01/2011
{code}
Now:
{code}
SQL> select * from XXCPP_SQL_LOADER_TEST;
no rows selected
SQL> host sqlldr scott/tiger control=c:\temp\XXCPP_SQL_LOADER_TEST.CTL log=c:\temp\XXCPP_SQL_LOADER_TEST.LOG
SQL> select * from XXCPP_SQL_LOADER_TEST;
PERSON_ID EMP_NAME   EMP_NUMBER START_DAT
         1 A                  11 13-JAN-11
         2 B                  12 13-JAN-11
         3 C                  13 13-JAN-11
SQL>
{code}
SY.

Order of Where clause

Hello GURUs
I have doubt about following. Please can all help me.
1. Does the order of table in from clause make difference. what should be the order. . largest to snmallest.
2. Does where clause order make difference. also left side to right side of equality comaprision. table row column on left and table column with less row on right.?
3. in USE_NL order of table make difference or not.? which one should be first one with less row or one with more rows. ?
4. Somtimes i have seen that USE_NL(table name) with only one table. in what condition that will be used. Larger or the smaller and then will the where clause make difference on that with USE_NL HINT.?
Message was edited by:
devmiral

Ok, because you insist :-)
I think you shouldn't care that much about these subjects, really. Oracle has an excellent cost based optimizer (cbo) that does all the work for you. It decides which predicate to apply first, the order of the tables and much more. But, and this is an important but, the cbo must have recent statistics of all the objects involved in your queries. So make sure you analyze regularly or use monitoring to stay up to date.
Applying hints like USE_NL is like saying: "I know way better than the cost based optimizer how to get the results quicker, so you should always use this access path".
Most of the time, however, something else is wrong, and by applying some hints you may (temporarily) fix the symptoms of your problem, but you are not addressing the root cause. So in case you feel the need to apply such a hint, please don't and start investigating what is really causing your problems.
Hope this helps.
Regards,
Rob.

Plz guide - ordering in where clause

This is in general ..
when we write query we will have 2 or more tables in from clause
what should be first in order to get optimum performance.
1. Joins of tables
2. filtering clauses eg. table.abc = 20
Plz help.
Thanx in advance.

in my own i have the practice of ordering it by according to the first declaration of tables/views in the FROM clause. e.g.
Select order.order_num,
         customer.customer_name,
         items.item_description,
         orders.quantity
    From orders,
         customers,
         items
   Where order.customer_id         = customers.customer_id
     and customers.customer_active = 'Y'
     and order.item_id             = items.item_id
     and items.item_active         = 'Y'

Nested where clause sql??

Hello,
I try to do the following sql
select a.emplid from
tableA a
where a.effdt =
(select max(b.effdt) from tableA b where a.emplid = b.emplid)
I try to use filter, it does not work, it complain that the table does not exist.
Please advise?
thnks

Currently OWB does not support subqueries. It will be supported in the next major version (November 2004).
In the meantime the (not very elegant) workaround for this is to create a view with the nested query.
Regards:
Igor

Order By in an SQL statement with DECODE

Hello all,
I want to order this as week days starting from monday till sunday and i have this code:
SELECT last_name, hire_date,
DECODE (TO_CHAR (hire_date, 'DAY'),
'MONDAY', 'MONDAY',
'TUESDAY', 'TUESDAY',
'WEDNESDAY','WEDNESDAY',
'THURSDAY', 'THURSDAY',
'FRIDAY', 'FRIDAY',
'SATURDAY', 'SATURDAY',
'SUNDAY', 'SUNDAY',
Order by(hire_date, 'DAY'))
AS DAY
FROM employees
ORDER BY DAY
but is not returning ordered as I want .. Any help..
this was done in HR Schema
Edited by: Paul Vidal on May 6, 2010 2:14 PM

but is not returning ordered as I want .. Any help..Of you don't get what you want because it contains a syntax error.
If you desire assistance, since we are not mind readers you need to actually tell us what you want.
ALWAYS
Post Operating System (OS) name & version for DB server system.(uname -a)
Post results of
SELECT * from v$version

Where clause priority in Select Query

Hi All,
I have one doubt, Pls clarify
SELECT empno, ename, sal, comm
FROM emp E, dept D -- (deptno is pk for DEPT)
WHERE D.deptno = E.deptno
AND E.sal >= 3000
In WHERE clause which one will execute first (right to left or left to right
OR[b] First join conditions then after filter conditions or vice versa)
D.deptno = E.deptno
OR
E.sal >= 3000
(this is the example tables)
Because I have large volume of data with 5 tables with joins
so, pls. kindly give me the sugession for where clause.
Thanks
Naresh

It depends, the order the where clause is written in makes no difference to how the statement is processed.
In the section on Developing Efficient SQL Statements in the Performance Tuning Guide changing the order of statements in the where clause is notably missing.
There is more information in the Understanding Joins section of the same manual.

Xi JDBC Adapter - Query SQL Statement & Update SQL Statement

Hi!
I configure the JDBC adapter sender (XI) to take data from Oracle database.
I set the Query and Update SQL Statement in the Processing parameters of the communication channel in this way:
Query SQL Statement :
SELECT * FROM XI_TABLE WHERE STATUS = 'WAIT' ORDER BY ROW_NUM
Update SQL Statement :
UPDATE XI_TABLE SET STATUS = 'DONE', DATE = SYSDATE WHERE STATUS = 'WAIT'
My question is :
If a new record with the field STATUS = 'WAIT' is added to the table (xi_table) during the time between the execution of the query statement and the start of the update statement, what will happen to that record during the update?
There is a way to avoid the update of that record? or to pass to the update statement only the record selected in the query statement?
Please, may you give me some example?
Thanks,
Francesco

hi,
did you check "Isolation Level for Transaction"
for the sender jdbc adapter?
http://help.sap.com/saphelp_nw04/helpdata/en/7e/5df96381ec72468a00815dd80f8b63/content.htm
Regards,
michal

Using SAMPLE with a WHERE clause

(Oracle 9iR2)
I am using the SAMPLE keyword in a SELECT statement with a WHERE clause. Is the sample extracted before or after applying the WHERE clause?
For example, if I have the statement:
SELECT emp_id FROM employees SAMPLE(10)
WHERE salary > 50000;
Does the database first extract a 10% sample of all the rows and then apply the salary filter on the sample (meaning it's possible that no rows are returned even though there are rows with salary > 50000)? Or does it return a 10% sample of the rows that meet the filter condition (meaning rows will always be returned as long as there are rows with salary > 50000)?

The sample is extracted before the where clause:
SQL> drop table sample_test;
Table dropped.
SQL> create table sample_test (id number, salary number);
Table created.
SQL>
SQL> begin
2 for i in 1..99 loop
3 insert into sample_test values (i, 100);
4 end loop;
5
6 insert into sample_test values (100, 1000);
7 end;
8 /
PL/SQL procedure successfully completed.
SQL>
SQL> commit;
Commit complete.
SQL>
SQL> select * from sample_test sample(5)
2 where salary > 100;
no rows selected

Parameter value in sql statement (Custom Folder)

Hi ,
I want to formulate a custom folder - consisting of a sql statement , inside of which there is a parameter. Then in Desktop , the users can select a number as the searching criteria and this value will replace the parameter in sql statement , as in the following:
select CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE , SUM_POSOTITA from
select CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE , SUM_POSOTITA , row_number() over (order by sum_posotita desc) rw from
(SELECT CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, TO_DATE(DATES_EKTELESIS,'DD/MM/RRRR') DATES ,SUM(POSOTITA) SUM_POSOTITA
          FROM EKTELESI_AT_SINT_CLINIC A, MITROO_FARMAKOU B
           WHERE CODE_FARMAKOU = FARMAK_CODE
           GROUP BY CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, DATES_EKTELESIS))
where rw<=&p
order by SUM_POSOTITA desc The problem is that the use of parameter , whereas in sql*plus is valid, in Discoverer is not....
What can i do in this situation...????
Thanks , a lot
Simon

However , a peculiar event happens....
whereas the sql statement is:
select CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE , SUM_POSOTITA,RW from
select CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE , SUM_POSOTITA , row_number() over (order by sum_posotita desc) rw from
(SELECT CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, TO_DATE(DATES_EKTELESIS,'DD/MM/RRRR') DATES ,SUM(POSOTITA) SUM_POSOTITA
          FROM EKTELESI_AT_SINT_CLINIC A, MITROO_FARMAKOU B
           WHERE CODE_FARMAKOU = FARMAK_CODE
           GROUP BY CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, DATES_EKTELESIS
UNION ALL
SELECT CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, TO_DATE(DATES_EKTELESIS,'DD/MM/RRRR') DATES,SUM(POSOTITA) SUM_POSOTITA
          FROM EKTELESI_AT_SINT_EX_IATR A, MITROO_FARMAKOU B
           WHERE CODE_FARMAKOU = FARMAK_CODE
           GROUP BY CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, DATES_EKTELESIS
UNION ALL
SELECT CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, TO_DATE(DATES_EKTELESIS,'DD/MM/RRRR') DATES,SUM(POSOTITA) SUM_POSOTITA
          FROM EKTELESI_AT_SINT_FOREON_MS A, MITROO_FARMAKOU B
           WHERE CODE_FARMAKOU = FARMAK_CODE
           GROUP BY CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, DATES_EKTELESIS
UNION ALL
SELECT CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, TO_DATE(DATES_EKTELESIS,'DD/MM/RRRR') DATES,SUM(POSOTITA) SUM_POSOTITA
          FROM EKTELESI_GEN_SINT_KLIN A, MITROO_FARMAKOU B
           WHERE CODE_FARMAKOU = FARMAK_CODE
           GROUP BY CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, DATES_EKTELESIS
UNION ALL
SELECT CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, TO_DATE(DATES_EKTELESIS,'DD/MM/RRRR') DATES,SUM(POSOTITA) SUM_POSOTITA
          FROM EKTELESI_GEN_SINT_EX_IATR A, MITROO_FARMAKOU B
           WHERE CODE_FARMAKOU = FARMAK_CODE
           GROUP BY CODE_FARMAKOU,EMP_NAME,PACKTYPE,PACKSIZE, DATES_EKTELESIS))
order by RW ascand produces the results....
CODE_FARMAKOU                            EMP_NAME                                                                         PACKTYPE                     PACKSIZE                  SUM_POSOTITA         RW
1000003279                               MOXACEF                                                                          BT                           40(BLIST10X4)                       45          1
0000014071                               DOPAMINE HYDROCHLORIDE                                                           VIAL                         5 ML X 25                           30          2
1000016655                               KABIVEN                                                                          BT                           50ÖÕÓ.×1,7ML                        21          3
1000014127                               DEPON VIT. C                                                                     BT                           2TUBX10                              6          4
0000002419                               FACTREL INJECTION                                                                VIAL                         2 ML                                 5          5
0000086289                               DETUSSIN EXPECTORANT                                                             BOT                          120 ML                               3          6
1000016655                               KABIVEN                                                                          BT                           50ÖÕÓ.×1,7ML                         2          7
1000014127                               DEPON VIT. C                                                                     BT                           2TUBX10                              2          8
1000000760                               DEPON                                                                            BT                           20(BLIST2X10)                        2          9
1000003279                               MOXACEF                                                                          BT                           40(BLIST10X4)                        1         10
1000003279                               MOXACEF                                                                          BT                           40(BLIST10X4)                        1         11
1000000760                               DEPON                                                                            BT                           20(BLIST2X10)                        1         12
12 rows selectedIn Discoverer , even i select to see -as parameter- let's say the 10 first records, the system displays the 7 first records , whereas when i want to see the 1,2,3,4,5,6,7 first records the system works fine....and displays accordingly 1,2,3,4,5,6,7 first records. The problem occurs above the 8th record-as parameter selected..!!!!!
I defined the parameter as :Rw<=:Rw
What may be the problem...????
SORRY!!!!! I FOUND THE PROBLEM ....!!!!
Regards and many thanks,
Simon
Message was edited by:
sgalaxy

Application goes halt while excecuting a SQL statement

Hello,
My application has a Database connection with JDBC-ODBC driver...
First I fill in an combo-box with data out of the database: let's say from the the Column "Name" in the Table "Children".
When I select a Child's name some labels apears where the details, from the child I selected, are shown.
I use the SQL statement: SELECT * FROM [database].[me].[Children] WHERE Name = 'Jacky';
When I click on a button named "Change Data", I want a dialog box to apear where the column names, empty TextFields and the "Old" Data is beeing shown.
I've created the Labels and the TextField, but when I come to the part where the SQL statement I beeing excecuted, my application halts.
This SQL statement is excectly the same as above:
SELECT * FROM [database].[me].[Children] WHERE Name = 'Jacky';
I don't get an Exception or something like that.
Can anybody help me please???

I use MS SQL-server 2000
I've created a new Database and that database is only accesible by my application.... and becouse I'm busy creating that application... I think I'm the only user on that database during the time I'm devolping the app.
But It is so that some where else in my code I call the same table with another Updatable ResultSet that might locks the whole table....
I'll try to close that one or to make that resultset ReadOnly.... and make the other resultset updatable again...
thnx for now....
Follyaxel

TestStand Open SQL Statement does not support SQL's ORDER BY clause???

TestStand 1.0.3
Windows 2000 SP1
SQL Server 2000 Personal
You've got to be kidding me...
It appears that the built-in TestStand Open SQL Step does NOT support the
"ORDER BY" clause in the SELECT statement, even though the documentation
says it does. Is this true?
I have an Open SQL Statement query:
"SELECT * FROM [MyTable] WHERE ([Batch ID]=1234)"
it works fine, returning a correct record count 120 records. If I change
the Open SQL Statement query simply by adding an ORDER BY clause, such as:
"SELECT * FROM [MyTable] WHERE ([Batch ID]=1234) ORDER BY [MyField] ASC"
it returns a record count of zero. I know that "MyField" exists in the
MyTable table and contains valid data. The
second query works fine in SQL
Server Enterprise Manager.
Am I missing something? Is it true that the TestStand Open SQL Step does
NOT support the "ORDER BY" clause? If not, what &#$!ing good is it and why
does the manual state it is supported? Is there any other way using just
the TestStand steps to order a database recordset on one or more fields?
Any help would be appreciated.
Grrrrr....
Bob Rafuse
Etec Inc.

> Bob -
> The database step types do not do anything special to the SQL command
> that you give it. The step just passes the command to the ADO
> provider. I tried a simple query using the step types with the
> following command,
>
> "SELECT UUT_RESULT.* FROM UUT_RESULT WHERE ([UUT_SERIAL_NUMBER] =
> 12345) ORDER BY [EXECUTION_TIME] ASC"
>
> and this return the expected results and the record count parameter
> was as expected. I tried this on TS 1.0.2 and TS 2.0 with MS Access
> 2000 and MS SQL Server 7.0. I do not have MS SQL Server 2000 at this
> time.
>
> It would be surprised if the step types are messing something up.
I've been doing some experimenting over the past couple of days. Simple,
one-table queries seem to handle the ORDER BY clause fine. Th
ings seem to
get messed up when I try multi-table queries with ORDER BY clause with the
TestStand database steps. I get no errors but the returned record counts
are always 0 with the ORDER BY and positive without the ORDER BY. The exact
same queries work fine in Visual Basic/ADO and the SQL Server Query
Analyzer.
> Questions:
> 1. Have you verified whether the data is actually returned even though
> the record count is zero?
Hmmm... yes data IS getting returned (at least on the two instances I just
checked), but the record count is always zero. I was not proceeding with
processing if the record count was 0.
Still... I don't know how to loop through the recordset without knowing how
many records there are an not eventually generate an error by passing EOF.
Is there another way using the TestStand database steps to determine a) the
number of records in the recordset or b) when I'm at EOF?
> 2. Are you using any advanced options on the Opend SQL Statement step
> type, specifically
the cursor type set to forward only? Forward only
> cursors do not allow for record counts.
Everything on the Advanced tab of the Open SQL Statement step is set to "Use
Default".
Bob.

Order in where clause - SQL statement

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