I am trying to understand "ordered" hint. I want to use it in my sql where I am using some left outer joins. I believe if I use this ordered hint it will be much faster.
But the problem is I am not able to understand the concept of this hint. As i did alot of search on this eveyone says it will be , even I got some similar references where it worked But I am getting contradicting explanation for on this.
I am observing some skewed results for Left outer join where the main table has NULL in the field we are joining against with another table.
Just wondering if there are some tricks to get over it. I am currently using NVL(tab1.col1,'X') = NVL(tab2.col3,'X') and am just wondering if there is a better way to handle this.
I have a select query that was working with no problems. The results are used to insert data into a temp table.
Recently, it would not complete executing. The explain plan shows a cartesian. But, there could be problems with using nested loops on the outer join.
Interestingly, when I copy production code and rename the temp table and rename the view, it works.
CREATE TABLE "CT"
( "TN" VARCHAR2(30) NOT NULL ENABLE,
"COL_NAME" VARCHAR2(30) NOT NULL ENABLE,
"CDE" VARCHAR2(5) NOT NULL ENABLE,
"CDE_DESC" VARCHAR2(80) NOT NULL ENABLE,
[Code]....
I have two tables employee_master and employee_time. There could be situation that record from employee_master does not exist in employee_time.
create table employee_master(employee_id number, employee_name varchar2(100));
insert into employee_master values(1, 'employee 1');
insert into employee_master values(2, 'employee 2');
insert into employee_master values (3, 'employee 3');
create table employee_time(employee_id number, project_id number, project_type varchar2(20), time_date date, hours number)
insert into employee_time values(1, 100, 'Billable', '01-Oct-2010', 10);
insert into employee_time values(1, 200, 'Billable', '02-Oct-2010', 9);
insert into employee_time values(1, 210, 'Non Billable', '03-Oct-2010', 10);
insert into employee_time values(2, 100, 'Billable', '01-Oct-2010', 10);
insert into employee_time values(2, 200, 'Billable', '02-Oct-2010', 9);
The requirement is to show all the employees from employee_master and with total billable hours and non billable hours, if not exist, show zero.The output will be:
Employee_ID Employee_Name Total_Billable_Hours Total_Non_Billable
1 Employee1 19 10
2 Employee2 19 0
3 Employee3 0 0
The question is to write a Left outer join query or to write a PL/SQL function which can return total rows if Employee_ID is supplied to it as a parameter
Query 1:
Select Employee_ID, Employee_name, sum(Billable), sum(Non_Billable)
From
(
Select a.Employee_ID, a.employee_name,
decode(b.project_type, 'Billable', hours, 0) as Billable,
decode(b.project_type, 'Non Billable', Hours, 0) as Non_Billable
from employee_master a
left outer join employee_time b on a.Employee_ID=b.Employee_ID
)
Group by Employee_ID, Employee_Name
Query 2:
Select Employee_ID, Employee_Name, func_billable(Employee_ID) as Billable, func_non_billable(Employee_ID) as Non_Billable
From Employee_Master
Which query is good from the performance perspective? In real situation the employee_time is a very huge table.
I have the following query but it is taking too much time because of the LEFT OUTER JOIN on HST table which is a huge table , is there an alternative to LEFT OUTER JOIN that can be used to optimize the code:
SELECT HST.COMP_CODE,
HST.BRANCH_CODE,
HST.CURRENCY_CODE,
HST.GL_CODE,
HST.CIF_SUB_NO,
HST.SL_NO,
SUM(CV_AMOUNT) CV_AMOUNT,
[code].....
i want to know the difference between Left outer join Vs. Right outer join? Its like which join is safer to use or is there any recommendations to use any join?
View 6 Replies View RelatedWhat is the fundamental difference between MINUS keyword and LEFT outer join in Oracle.
I can achieve same results using either one of them.
I am using left outer join to fetch PRSN_KEY .I need to find null values in B.PRSN_KEY. I am using below query but its giving me 0 count.
select count(*) from (
Select A.PRSN_KEY AS AKEY,B.PRSN_KEY AS BKEY from CD03955P.H_CM_EEST_EEOR A LEFT JOIN CD03955P.H_CM_EEST_EEOR B
ON
A.PRSN_KEY =B.PRSN_KEY
where
A.CAT_ID=111
AND
A.DATA_SOURCE='PEN_CO'
AND
B.CAT_ID = 1 and B.DATA_SOURCE ='PEN_EEST'
AND B.CAT_CD IN ('ACTIVE','LOA','LOAWP','LOAMLP','LOAMLN')
AND B.EFBEGDT < A.EFBEGDT
)
where BKEY IS NULL
What I am trying to do is get my report to list every room in the table even if there is nothing scheduled in the room for the selected date. I add a command to the report to force the left outer join but I keep running into errors. This is how I have it worded:
SELECT
"ROOM"."ROOM_ID",
"PATIENT_CARE_EVENT"."OR_NUM"
FROM
"ROOM"."ROOM" LEFT OUTER JOIN "PATIENT_CARE_EVENT"."PATIENT_CARE_EVENT"
ON "PATIENT_CARE_EVENT"."OR_NUM"="ROOM"."ROOM_ID" AND "PATIENT_CARE_EVENT"."PROCEDURE_DATE_DT" IN {?Start Date} TO {?End Date}
Someone else suggested that I change the IN/TO wording in the last line to BETWEEN/AND. When I do that it gives me an error stating that the table or view does not exist.
these are the sample data :
CREATE OR REPLACE TYPE CourseList AS TABLE OF VARCHAR2(64);
CREATE TABLE department (
courses CourseList)
NESTED TABLE courses STORE AS courses_tab;
INSERT INTO department (courses)VALUES (CourseList('1','2','3'));
[code]....
The query returns the correct data, CourseList that are not subset of any other CourseList of the table.
I am trying to convert this not exists in a left outer join query to check if the performance is better, but I don't know how to do it.
I was making some variations of this code :
select d1.courses c_1, d2.courses c_2
from department d1,department d2
where d1.courses<>d2.courses(+);
but it is now working.
There's a fairly popular Ordered Hint example on the web as follows:
<CODE>
select /*+ ordered use_nl(bonus) parallel(e, 4) */
e.ename,
hiredate,
b.comm
from
emp e,
bonus b
where
e.ename = b.ename
;
</CODE>
I would like to know what the "parallel(e, 4)" clause does. Where does the "4" come from? What is "parallel" here? I also have another question: If I have 5 tables--T_OREGON, T_UTAH, T_VIRGINIA, T_TEXAS, and T_OKLAHOMA--lined up in a join right behind a FROM, coming in at row counts of
T_OREGON: [a lot of rows; a lot more than T_UTAH]
T_UTAH: [smaller than T_OREGON] 40550 rows
T_VIRGINIA: 14 rows
T_TEXAS: 66 rows
T_OKLAHOMA: 8 rows
from T_OREGON or, T_UTAH ut, T_VIRGINIA va, T_TEXAS tx, T_OKLAHOMA ok...
my question is, if an Ordered hint can be used here, is it that the smallest table (in this case T_OKLAHOMA) gets placed first in the join and the rest of the table ascension in the join doesn't matter? Or is it that T_OKLAHOMA gets placed first in the join, followed by T_VIRGINIA [at 14 rows], followed by T_TEXAS, T_UTAH, and finally T_OREGON?
I have following data
WITH t AS
(
select 1 rn, 'A' val from dual UNION ALL
select 2 rn, 'A' val from dual UNION ALL
select 3 rn, 'B' val from dual UNION ALL
[Code]....
I need to calculate a new column "orderedRn" as
Rn Val OrderedRn
------------
1 A 1
2 A 1
3 B 2
4 C 3
5 C 3
6 C 3
7 A 4
8 A 4
9 B 5
10 B 5
I have to update a column for all the records in the table with a unique contraint
ex-- select rec_no from tablename;
9
8
7
6
5
now i have to update this like
select rec_no from tablename;
8
7
6
5
4
but when i am doing update tablename set rec_no=rec_no-1 i am getting unique constraint error
AWR Report regarding ' SQL ordered by Physical Reads (UnOptimized))'. SQL ordered by Physical Reads (UnOptimized)UnOptimized Read Reqs =
Physical Read Reqts - Optimized Read Reqs %Opt - Optimized Reads as percentage of SQL Read Requests %Total - UnOptimized Read Reqs as a percentage of Total UnOptimized Read Reqs Total Physical Read Requests: 3,311,261 Captured SQL account for 13.5% of Total Total UnOptimized Read Requests: 3,311,261 Captured SQL account for 13.5% of Total Total Optimized Read Requests: 1 Captured SQL account for 0.0% of Total UnOptimized Read ReqsPhysical Read ReqsExecutionsUnOptimized Reqs per Exec%Opt%TotalSQL IdSQL ModuleSQL
[code]....
I want to know what is the mean by 'UnOptimized Read Reqs' and 'Optimized Read Reqs 'Question 2) what is 'SQL ordered by Physical Reads tuning'.
Elapsed Time (s)CPU Time (s)Executions Elap per Exec (s) % Total DB TimeSQL IdSQL ModuleSQL Text
3,263 32 1 3263.49 2.79 3ta0ms19fvgds httpd.exe SELECT CASE WHEN COUNT >= 1...Elapsed
6,360 164 2 3180.17 5.44 51jx99dm0swv7 cpm_srvscript@ahcaxasmil1b (TNS V1-V3) SELECT /*+ CCL<PFT_GET_RP...
On AWR, I see two script that are out of ordinary, and I want to make sure that I interpret them correctly.
1) "Elap per Exec (s)" shows 3263.49 with 1 "Executions".
2) "Elap per Exec (s)" shows 3180.17 each execution with 2 "Executions".
Does this mean that this script ran for ~ 54 minutes (3263.49 / 60 seconds) for 1 "Execution" and ~ 53 minutes (3180.17 / 60 seconds) per each execution? I need to understand "Elapsed Time (s),CPU Time (s),Executions ,Elap per Exec (s), % Total DB Time" represent.
is any way to export an Oracle database organized in manner that, both tables and constraints would be exported in the correct order.An easy sample:
- An database with 2 tables, with constraints between them. Table 1 has a FK on Table 2.
Is it possible to export both structure and data regarding the constraints, resulting in an script that makes it possibly to import it in a way that would not give me problems about constraints?
Elapsed Time (s) CPU Time (s) Executions Elap per Exec (s) % Total DB Time SQL Id SQL Module SQL Text
2,423 1 3,919 0.62 1.83 gt49gg0fnc5x8 srv_dr@ahs (TNS V1-V3) UPDATE /*+ CCL<OENDB_FILE...
2,227 14 1 2227.16 1.68 bggfx8a04prj9 SQL*Plus select * from (select n.source...
.........
On [SQL ordered by Elapsed Time], [SQL Module] shows an indication that a SQL was executed by which process (i.e. srv_dr@ahs)outside of SQL*PLUS.If [SQL Modeule] shows as [SQL*Plus], does it mean the query was run in SQL*PLUS manually or directly?I have the SQL ID. How do I find out who, how, and exactly what time it was run?
I'm very happy about materialize hint and I use it a lot. But is it possible to set some hint indicating that I want to materialize some inline view results (temp table transformation) as IOT (index organized table)?
IOT must have primary key. Ok, could it be all the columns in listing order? That would convenient. I know I can use global temporary with index, but this forces me to split one statement into parts.
I've got SQL code generated by an HP tool to make an update of itself. This code is not modifiable because was execute 'in background' from the tool updater.
The macro operations made by the updater (through sql code) are:
--create a copy of actual table and rename with '_old' suffix
--create new table, with indexes and constraints
--insert data into new table from old tables
Now, only in one table, when the data were inserted, an ORA-00001: unique constraint (ASSET_SVIL.CFG_CFGSECTIONCFGE) violated, appear.
To insert data is used an insert/select statement with an HINT /* APPEND */. We verify all the data existing in the old table (that is the data to 'migrate') but there aren't duplicate record!
BUT IF WE REMOVE THE HINT /* APPEND */, THE INSERT/SELECT STATEMENT WORKS WITHOUT GENERATE ERRORS!!
I have been told that i should use multiple's of 4 as degree in the parallel hint to get maximum performance, so i am wondering is it true? that i should always use multiples of 4 or i can use any number inside the parallel hint.
View 4 Replies View RelatedI have a SQL query where I am making UNION of two select statements. The table that I am joining in each select statement have indexes defined for those tables.
Now the UNION of the two select statements again in enclosed in an inline view , from which I fetching my final field values.
The select statements inside the inline view returns huge number of row (like 50 million rows).
The whole query fails with time out.
How can I optimize this query further?
Is there a way to pass Oracle Hints so that Oracle uses indexes?
I have been asked to rewrite the following update statement without using the hint BYPASS_UJVC.
l_new_CFT_ID CASHFLOW_TYPE.CFT_ID%TYPE;
if (l_Record > 0) then
-- since at least 1 loan was found with the old type, process the actual update
update /*+BYPASS_UJVC*/ (
select
cfa.CFA_CFT_ID
[code]......
I think I am supposed to be using the Merge statement but I am not sure on how to go about it.
I have a query with FULL hint that is behaving in a strange manner. The query fetches around 700000 of data. Sometimes it fetches the data with the hint and sometimes it does not fetch any data with the hint and then I have to remove the hint and have to fetch the data. Below is the query,
select /*+ FULL(COMP_TM) FULL(TRANS_TM) FULL(INVC_TM) */
CUST_BE_ID ,
DISTR_BE_ID ,
FG_BE_ID ,
KIT_BE_ID ,
BG_ID_NO_BE_ID ,
[code]....
The statistics gathering activity of FACT_DLY_ALGND_SLS table takes around 5 hours to complete. It is a range partitioned table with subpartitions.
I am writing below MERGE statement. In this cardinality between table_a and table_b is 1:2. I.e. each record in table_b corresponds to 2 records in table_a based on columns in ON clause.
Well this query throws below error.
----Error---
ORA-12801: error signaled in parallel query server P011
ORA-30926: unable to get a stable set of rows in the source tables
However, the same statement executes successfully when PARALLEL hint is removed altogether. (There are no duplicates in table_b based on unit,group,loc columns.)
-----Query--------
MERGE /*+ PARALLEL(8) */
INTO table_a a
USING table_b b
ON (a.unit = b.unit AND a.group = b.group AND a.loc = b.loc)
[Code]....
Does parallel hint works in cursor queries? The cursor query is something like :
cursor c is
select /*+ parallel(s,8) */
from table ref_tab s ---- >>
<where condition>;
The table ref_tab hold data for a single day at any point of time and gets truncate before loading the next days data.On average the table holds around 7 million rows and doesn't contains any index (think that's fine as all together we are loading the whole set).And, we are using bulk logic with save exceptions to open the cursor and load the data into the target table.
I have a SQL query where I am making UNION of two select statements. The table that I am joining in each select statement have indexes defined for those tables.
Now the UNION of the two select statements again in enclosed in an inline view , from which I fetching my final field values.
The select statements inside the inline view returns huge number of row (like 50 million rows).
The whole query fails with time out.
Is there a way to pass Oracle Hints so that Oracle uses indexes?
select
serialnumber from product where productid in
(select /*+ full parallel(producttask 16) */productid from producttask where
startedtimestamp > to_date('2013-07-04 00:00:00', 'YYYY-MM-DD HH24:MI:SS')
and startedtimestamp < to_date('2013-07-05 00:00:00', 'YYYY-MM-DD HH24:MI:SS')
and producttasktypeid in
[code]....
Explain plan output:
Plan hash value: 2779236890
-----------------------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name| Rows| Bytes | Cost (%CPU)| Time| Pstart| Pstop |
-----------------------------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT || 1 | 29 | 9633M (8)|999:59:59 |||
|* 1 | FILTER |||| ||||
| 2 | PARTITION RANGE ALL || 738M| 19G| 6321K (1)| 21:04:17 | 1 | 6821 |
[code]....
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter( EXISTS (<not feasible>)
4 - filter("PRODUCTID"=:B1)
5 - filter(ROWNUM<100)
12 - access("MODELID"=:B1)
[code]....
Note: - SQL profile "SYS_SQLPROF_014153616b850002" used for this statement
I have an APP that truncates tables and loads data, which in turn makes the stats stale. I ran the query advisor (see attachment) and of course it ecommends running stats or accept a profile.I really don't want to do that as it may cause a load on my DB.
In turn, I would like to consider having my APP team change the query to pass a hint to use the best query plan.syntax to pass the hint to emulate good attached plan? Or is this a bad way to proceed?
select /* INDEX FAST FULL SCAN PK_PLACEMENT_REQUEST_QUEUE */
sum(lastshares) as "ROSEN"
from nyeo.fix_exec_reports fer, nyeo.placement_request_queue q,
nyeo.nyeo_block_control bc
where fer.clordid = q.sequence_number
and q.blockid = bc.blockid
and upper(bc.deskname) like '%ROSEN%'
does parallel hint in query can create bottleneck/Slowdown/crash database..??
View 4 Replies View RelatedI have a table1:
userid, name, town.
Now i want to do a self join like:
select a.name, b.name, a.town
from table1 a
inner join table1 b
on a.town = b.town
where a.first_name <> b.first_name AND
a.last_name <> b.last_name
i added the where clause to limit duplicates i would get but i still get duplicates eg. A B london, B A london etc.