high number of executions of specific types of queries which is using only rownum clause. For exam.
select ani, rowid from tbl_smschat_upuor where rownum<=:"SYS_B_0";
DB is having high number of executions of these type of queries and these when I m checking the execution plan for the same type of queries it is accessing the full table scan.
======================execution plan for above query 1000 rows selected. Execution Plan ---------------------------------------------------------- Plan hash value: 91289622 --------------------------------------------------------------------------------
how to select 1st record from duplicate vales in a table.
If we created one table with out primary key column In form in search block have uwi value and top_depth value when i enter uwi and top_depth value then when i click search button then it will display all values in master block.
but here duplicate values r there.
SQL> select rownum,uwi,top_depth,base_depth,test_start_date from well_pre_header;
I tried to make my Query as simple as possible but also it contains the problem:
SELECT A.Id,A.Attachment,A.CreateDateTime,A.No ,rownum as RowNumber FROM ( SELECT A.Id,A.Attachment,A.CreateDateTime,A.No FROM GOutgoingLetter A , ( SELECT B.Id, B.createdatetime as of0 FROM GOutgoingLetter B WHERE Exists [code]...
when I use Both Order By And RowNum in my Query, Two columns of final Select Are Null: NO & Attachment. whereas this Columns aren't empty.when I comment each one of "ORDER BY B.of0" or ",rownum as RowNumber " everything is correct!!
Is there a technique to getting a Top-N query to work as a sub-select in a larger query -or- is there another way to generate Top-N like results that works as a sub-select?
Background:
We have a large query that is being used to build an export from a legacy HR system to a new one. Amount the data needed in the export is the employees primary phone number.
The legacy HR system allows multiple phone numbers to be stored in a simple table structure:
SELECT emp_id, phone_type, phone_number FROM employee_phones
The new HR system does allow for multiple phone numbers, however they need a primary phone number identified and stored with the employee master information. (Subsequent phone numbers get stored in alternate table.)
From a business perspective, we have decided that if they have a HOME phone in the legacy system that should be the primary in the new system, if no HOME phone, then WORK, if no WORK then CELL.
That can be represented as:
SELECT * FROM employee_people_phones WHERE emp_id = '46021' ORDER BY decode(phone_type, 'HOME', 'a', 'WORK', 'b', 'CELL', 'c', 'z')
SELECT * FROM (SELECT * FROM employee_people_phones WHERE emp_id = '46021' ORDER BY decode(phone_type, 'HOME', 'a', 'WORK', 'b', 'CELL', 'c', 'z')) results WHERE ROWNUM = 1
SELECT phone_number FROM (SELECT phone_number FROM employee_people_phones WHERE emp_id = '46021' ORDER BY decode(phone_type, 'HOME', 'a', 'WORK', 'b', 'CELL', 'c', 'z')) results WHERE ROWNUM = 1
phone_number ------------------- 1111111111
However, when the Top-N query is added as a sub-select in a larger query using the employee id from the larger query (WHERE emp_id = export.emp_id), it fails saying that �export.emp_id� is not a valid id.
(SELECT phone_number FROM (SELECT phone_number FROM employee_people_phones WHERE emp_id = export.emp_id ORDER BY decode(phone_type, 'HOME', 'a', 'WORK', 'b', 'CELL', 'c', 'z')) results WHERE ROWNUM = 1)
1.Any way around this? Is it possible to put a Top-N (with a WHERE clause using data from the main query) in a sub-select?
2.Any alternatives (other than Top-N) to delivering a ROWNUM=1 result with a �custom� ORDER BY statement?
Other Notes: Yes, we know we could do two queries in the data conversion first deliver the bulk data to the target table, and then update with the phone numbers. However, for multiple reasons, that is less than desirable.
There are over 1500 records, but this query does not return any row. If i change rownum >= 100 to rownum <= 100 it returns first hundred records though... What is wrong here?
When i try to execute a query, which is organised as the below example, it retrieves data..
select * from ( select col1, col2, col3, col4....coln from TABLE_ONE left outer join TABLE_TWO -- some conditions and group by clause order by 1 asc ) where rownum <=1000;
Again if I use Column alias in the ORDER BY clause col1, the query won't retrieve data.
Also If I use ORDER BY 4 instead of ORDER BY 1, the query wont return data...
select * from ( select col1, col2, col3, col4....coln from TABLE_ONE left outer join TABLE_TWO -- some conditions and group by clause order by 4 asc ) where rownum <=1000;
The whole issue revolves around the inner ORDER BY Clause and external ROWNUM condition..If I eliminate any of the two, the query works fine...I am not sure if indexes have some role to play in it...
I'm on Oracle Database 10g Enterprise Edition Release 10.2.0.4.0
I am working on a project where have lots of view on a different schema. For performance reasons, we create tables on those views and index them.
The application that uses these tables requires a numeric primary key of a specific length, e.g. number(10). Not all tables have a natural key that matches this requirement, so I added a rownum to the query. I had hoped that casting the rownum to a number(10) would result in the same datatype once the table is created.
e.g. SQL> create or replace view rownum_to_number10_vw as 2 select cast(rownum as number(10)) objectid, dummy from dual;
View created
SQL> describe rownum_to_number10_vw; Name Type Nullable Default Comments -------- ---------------- -------- ------- -------- OBJECTID NUMBER(10) Y DUMMY VARCHAR2(1 BYTE) Y
SQL> perfect! Now create a table based on this view:
SQL> create table rownum_to_number10_tb as 2 select * from rownum_to_number10_vw;
Table created
SQL> describe rownum_to_number10_tb; Name Type Nullable Default Comments -------- ---------------- -------- ------- -------- OBJECTID NUMBER Y DUMMY VARCHAR2(1 BYTE) Y Oracle does not pick up on the number(10) cast!
How can I force Oracle to create a column with the same datetype as the underlying query?
ps:I know that the 10 in number(10) is more like a constraint than a datatype, but the application that uses this table will create an additional column if the datatype > 10. I want to prevent that from happening...
I have a requirement in SQL that I have to number each row. Hence I thought of using ROWNUM. But the sql query I'm using uses UNION operator. Hence I used like this
select a,b,rownum as 'field1' from table1 union select c,d,1 as 'field1' from table2
I have a result set with three columns as 'Product Category', 'Product' & 'QtySales' and 10 rows, sorted in the order Product Category, Product. This means, a product category will have one or more products under it.
Now i want to add a fourth column to my result set, which should display a incremental number sequence from starting from 1, 2, 3.. for each row. Also when the value of the Product Category (1st column) changes, this sequence should be restarted again from 1.
Using rownum in PL/SQL can significantly reduce performance and throughput of queries.
For example,
CODEselect * from (select ... from ... join ... on ... join ... on ... left join ... on ... where ... group by ...) where rownum < 500
takes much more time on a heavy loaded db than
CODEselect Y.* from ( select X.*, rank() over(order by ...) rnk from (select ... from ... join ... on ... join ... on ... left join ... on ... where ... group by ...) X) Y where rnk < 500
I suspect it's because Oracle optimizer goals all_rows and first_rows.
I am trying to do a simple query where I need to return the rows from a table and treat each rown according to some rules.The query works fine, and returns all the rows, usually I have 2 rows returned. WHen I add to the query where ROWNUM = 1, I get the first row returned, but when I use when ROWNUM =2 OR ROWNUM >1, I always get null rows retured, even if I have rows in the database. Here is my query:
SELECT on_time INTO on_time2 FROM work.work_unit WHERE work_code = 1 AND emp_no = :entry_blk.p_emp_no AND work_date = :entry_blk.p_work_date WHERE ROWNUM = 2; --RETURN NULL
I changed it to the following format, but still I get the same results, only I get data when I say when rownum = 1, i get back the first record in the query
SELECT on_time INTO on_time2 FROM (SELECT on_time FROM work.work_unit WHERE work_code = 1 AND emp_no = :entry_blk.p_emp_no AND work_date = :entry_blk.p_work_date) WHERE ROWNUM = 2;
I can't move forward in my form until I figure out why this is not returning records
title varchar2(100) y publisher varchar2(20) y categoryname varchar2(20) y rating varchar2(2) y
my query is, select ROWNUM AS "Rank",title,publisher from (select rating,title,publisher from bookshelf_test order by rating desc ) where ROWNUM <=3
returns result ,
1 1 MY LEDGER KOCH PRESS 2 2 TO KILL A MOCKINGBIRD HARPERCOLLINS 3 3 THE MISMEASURE OF MAN W.W. NORTON
But inner query (select rating,title,publisher from bookshelf_test order by rating desc ) returns,
1 5 WONDERFUL LIFE W.W.NORTON 2 5 THE MISMEASURE OF MAN W.W. NORTON 3 5 TO KILL A MOCKINGBIRD HARPERCOLLINS 4 5 MY LEDGER KOCH PRESS 5 4 TRUMAN SIMON SCHUSTER 6 4 GOSPEL PICADOR 7 4 HARRY POTTER AND THE GOBLET OF FIRE SCHOLASTIC 8 4 INNUMERACY VINTAGE BOOKS 9 4 JOHN ADAMS SIMON SCHUSTER 10 4 JOURNALS OF LEWIS AND CLARK MARINER 11 4 LETTERS AND PAPERS FROM PRISON SCRIBNER 12 4 PREACHING TO HEAD AND HEART ABINGDON PRESS 13 4 THE SHIPPING NEWS SIMON SCHUSTER 14 4 THE GOOD BOOK BARD 15 4 THE DISCOVERERS RANDOM HOUSE 16 3 THE COST OF DISCIPLESHIP TOUCHSTONE 17 3 SHOELESS JOE MARINER 18 3 KIERKEGAARD ANTHOLOGY PRINCETON UNIV PR 19 3 EMMA WHO SAVED MY LIFE ST MARTIN'S PRESS 20 3 EITHER/OR PENGUIN 21 3 CHARLOTTE'S WEB HARPERTROPHY 22 3 BOX SOCIALS MARINER 23 3 ANNE OF GREEN GABLES GRAMMERCY 24 3 WEST WITH THE NIGHT NORTH POINT PRESS 25 3 UNDER THE EYE OF THE CLOCK ARCADE PUB 26 3 TRUMPET OF THE SWAN HARPERCOLLINS 27 2 COMPLETE POEMS OF JOHN KEATS VIKING 28 1 POLAR EXPRESS HOUGHTON MIFFLIN 29 1 GOOD DOG, CARL LITTLE SIMON 30 1 MIDNIGHT MAGIC SCHOLASTIC 31 1 RUNAWAY BUNNY HARPERFESTIVAL
why final queries top 3 rows r different than inner query ?
We're using Oracle 10g for development purposes. I have 2 same schema with approximately same data. I'm running same query on 2 schemas and I see that the first schema runs the query around 20sec and the 2.schema less than 1 sec. I thought first that there may be missing constraints or indexes but all are the same.
I checked the plan for the 2 schemas and I see that the plan is different.
Here is the query: SELECT ccc.ComponentId AS "ComponentId", ccp.Code AS "ParentCode", ccc.Code AS "ChildCode" FROM CatalogueComponent ccp INNER JOIN CatalogueComponent ccc ON ccp.ComponentId = ccc.ParentComponentId WHERE ccc.ComponentId IN (20934777, 1594747)
I'm sending also the 2 output of PLAN results from 2 different schemas.
what should I do to fix the problem with the NAFBCA schema.
SELECT DISTINCT PATIENT_ID , ( SELECT ROWNUM,APPOINTMENT_ID FROM AppointmentDetailsHistory WHERE APPOINTMENT_STATUS_ID = 2 AND VISIT_TYPE_ID NOT IN (7) AND PATIENT_ID = ADH.PATIENT_ID
[code]...
MY SELECT query failing actually i am trying to convert sql server select into oracle.My sql server query is like this.
SELECT DISTINCT PATIENT_ID , ( SELECT TOP 1 APPOINTMENT_ID FROM EMRAppointmentDetailsHistory WHERE APPOINTMENT_STATUS_ID = 2 AND VISIT_TYPE_ID NOT IN (7) AND PATIENT_ID = ADH.PATIENT_ID ORDER BY PATIENT_ID, LAST_UPDATED_DATE ASC) AS FIRST_APPOINTMENT FROM EMRAppointmentDetailsHistory ADH WHERE ADH.APPOINTMENT_STATUS_ID = 2 AND ADH.VISIT_TYPE_ID NOT IN (7)
We're using Oracle 10g for development purposes.I have 2 same schemas with approximately same data.I'm running same query on 2 schemas and I see that the first schema runs the query around 20sec and the 2.schema less than 1 sec. I thoughtfirst that there may be missing constraints or indexes but all are the same.I checked the plan for the 2 schemas and I see that the plan is different.
Here is the query: SELECT ccc.ComponentId AS "ComponentId", ccp.Code AS "ParentCode", ccc.Code AS "ChildCode" FROM CatalogueComponent ccp INNER JOIN CatalogueComponent ccc ON ccp.ComponentId = ccc.ParentComponentId WHERE ccc.ComponentId IN (20934777, 1594747)
I'm sending also the 2 output of PLAN results from 2 different schemas.
write a query to get the first row after order by clause using single query alone.Example:I can write following query to select first rowselect * from (selec * from t order by col1) where rownum = 1;But here I should not use inline view to get the result. Because my original requirement needs to use this query in select list and it needs to use a column (of a table from the FROM clause) in the where clause of inline query. Because there is restriction that we can not use the column (of a table from the FROM clause) more than one level of inline query.
--insert into t1(col1, col2, flag) values(1, 'a', 'Y'); --insert into t1(col1, col2, flag) values(2, 'b', 'N');
SELECT * FROM t1 x WHERE col1 = 1 AND col2 = 'a' -------------- condition1 AND 0 = -------------- condition2 NVL ( (SELECT COUNT (1) FROM t1 y WHERE y.flag = 'N' AND x.col1 = y.col1 AND x.col2 = y.col2),0)--=0
When remove NVL function or change the condition by having AND NVL(SELECT) =0 the query working fine.
I have a table A on dev with definition as TAble A(address,name) and the same table on Prod is defined as Table A(name,address).
my question is Ihave one package in that am trying to insert into this table as follows:
INSERT INTO A SELECT b.name name, a.address address,
[Code]....
so the query works on Prod but fails on Dev because column order is different.
I have 2 solutions:
1. I can mention column names in insert line and modify the query but tomorro some body changes again the definition of table A I need to change the query, so do I have solution in oracle sql that can handle the column order without specifying the column names in insert line.
so tomorrow On prod column order and on Dev column order is different though my sql should successfully execute.
i have a good query but I thought i know the solution but actually I didn't it's very simple and straight forward but i didn't catch the rope terminal to follow now I have the following code
NOW I NEED A QUERY which will select the only translator who knows the languages written in where clause like if i specify two languages like 'italy' and 'english' the query should retrieve to me GH and SE also if i passed languages 'spainsh' and 'persia' it should return JH only
but if i passed languages like 'Italy' and 'Dutch' it should not return any thing (just : no rows selected)