N-way joins - interim table

Hi all,
I got a question concering n-way joins. Just for a better understanding: if I join multiple tables with natural joins, every join creates an interim table with just the specified columns in the select list.
How does that acctually work with "using" and "on" joins. E.g. (copied from oca sql fundamentals book):
select r.region_name, c.country_name, l.city, d.department_name
from departments d
join locations l on (l.location_id=d.location_id)
join countries c on (c.country_id=l.country_id)
join regions r on (r.region_id=c.region_id)
I know that the joins will be evaluated from left to right. So we start with departments join locations. How would the interim table look like in this case? Is it also just the a table with d.department_name and l.city? Is this table joined with countries?
I'm a bit perplexed ...
Thanks in advance

I don't have the book that you're referring to.
I don't know if the terminology you're using is from there or is your own.
I know that the joins will be evaluated from left to right. So we start with departments join locationsNot true at all.
There might be rules on semantic checking or code evaluation, for example, operator precedence being from left to right:
http://download.oracle.com/docs/cd/E11882_01/server.112/e17118/conditions001.htm#SQLRF52103
but that is very different from join order and execution plan - that is an optimizer decision based on several factors.
I'm not sure that I like the term "interim table" either.
Each join operation will provide a rowsource but maybe we shouldn't get too hung up on semantics
every join creates an interim table with just the specified columns in the select listNot necessarily. It depends on the execution plan and the operation. But in general, at the very least you're going to have the join column/s and selected columns if relevant to that rowsource.

Similar Messages

Best way to outer join a table that is doing a sub query

RDBMS : 11.1.0.7.0
Hello,
What is the best way to outer join a table that is doing a sub query? This is a common scenario in EBS for the date tracked tables.
SELECT papf.full_name, fu.description
FROM fnd_user fu
      ,per_all_people_f papf
WHERE fu.user_id = 1772
   AND fu.employee_id = papf.person_id(+)
   AND papf.effective_start_date = (SELECT MAX( per1.effective_start_date )
                                      FROM per_all_people_f per1
                                     WHERE per1.person_id = papf.person_id)Output:
No output produced because the outer join cannot be done on the sub queryIn this case I did a query in the FROM clause. Is this my best option?
SELECT papf.full_name, fu.description
FROM fnd_user fu
      ,(SELECT full_name, person_id
          FROM per_all_people_f papf
         WHERE papf.effective_start_date = (SELECT MAX( per1.effective_start_date )
                                              FROM per_all_people_f per1
                                             WHERE per1.person_id = papf.person_id)) papf
WHERE fu.user_id = 1772
   AND fu.employee_id = papf.person_id(+)Output:
FULL_NAME     DESCRIPTION
{null}            John DoeThanks,
--Johnnie

Hi,
BrendanP wrote:
... See the adjacent thread for the other with Row_Number().Do you mean {message:id=10564772} ? Which threads are adjacent is always changing. Post a link.
I think RANK suits the requirements better than ROW_NUMBER:
WITH    all_matches     AS
     SELECT papf.full_name
     ,      fu.description
     ,     RANK () OVER ( PARTITION BY papf.person_id
                           ORDER BY          papf.effective_start_date     DESC
                    )           AS r_num
     FROM             fnd_user             fu
     LEFT OUTER JOIN      per_all_people_f papf ON fu.employee_id = papf.person_id
     WHERE   fu.user_id = 1772
SELECT     full_name
,     description
FROM     all_matches
WHERE     r_num     = 1
Johnnie: I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) for all tables involved, and also post the results you want from that data.
See the forum FAQ {message:id=9360002}

No Easy Way to Join on Tables from Different Schemas

Hi,
The company policy does not allow to join on tables from different schemas or use db links...
I'm tasked to come up with a Perl script that does exactly that - allows for the SELECT statement to do several joins on 3 different schemas. In addition 1 of the schemas is on the different host altogether.
Upping the privileges for my user and allowing db links is not an option...Can someone, please help me to understand on a conceptual level how would I use Perl and what logic would it have and what would it (perl) do?
Thank you,

Court in the wrong job... ;)
It's like a librarian who is a hard rock artist maintaining the silence in the premises. ;)
My dear friend, i don't think this is the right place for your requirement. This is the PL/SQL forum. If you have any problem related PL/SQL or SQL you can place that here.
Regards.
Satyaki De.

Using a view to join two tables

Thank you in advance for any advice you can lend.
I am using this code in my MySQL db to create a view.
select
    job.id as job_id,
    umr_cost_calculation.plant_name,
    max(umr_cost_calculation.id) as max_id
from
    job,
    umr_cost_calculation
where
    job.id = umr_cost_calculation.job_id
group by job.id , umr_cost_calculation.plant_name
I did this so I can join two tables and pull in the most current cost data for a specific plant. The report will, at times, show the wrong (older) data. I can re-run the report, filter to just the one job and see again the wrong data. When I add the max_id to the report, it display the id and updates the report with the correct data. It appears that the view was stale and by adding the ID to the report this fixed the issue.
1) Is this the best way to make this join? I don't see how Crystal supports a subquery to make a join (this is why I used the view).
2) If I leave the max_id on the report, will this force the view to always update?

Try:
Select
D1.EmpLoginID,
Count(D1.ID),
Count(D1.AlarmCode),
D1.EmpName,
D1.EmpAddress,
D2.Db2Count
FROM DB1.Data D1
LEFT JOIN (SELECT
empLoginID, Count(*) as Db2Count
FROM DB2.ALL_Database
WHERE site = 'Atlanta'
GROUP BY empLoginID
) D2
ON D1.EmpLoginID = D2.EmpLoginID
GROUP BY D1.empLoginID, D1.EmpName, D2.EmpAddress, D2.Db2Count
Order BY D1.empLoginID ASC
For every expert, there is an equal and opposite expert. - Becker's Law
My blog
My TechNet articles

Join fact table with higher dimension level

how do i join fact tables with higher dimension levels with discoverer?
fact with detail at level C
measure X
dimension with
D->C->B->A
E->C
level
A B C
1------1------1
2------2------1
3------2------1
join between fact X and dimension level C
X=3*C because of sum(X) in discoverer and 3xC in dimension
is there a way to get correct values for X without creating a dimension like
D->C
E->

another way of asking this is whether you can create a summary table in Discoverer at a higher level than a dimension's fundamental grain. In other words - the summary examples in the documentation all describe leaving out one or more of your dimensions... they are either left in or completely taken out. But, some of the most effective summarization occurs when you summarize daily data to a monthly level. Assuming that I have a sales table (at a daily level, and a key value sales_date), and a table date_dim (primary key sales_date), I would like to create a summary sales_month_summary where the sales are grouped on month_year (which is a field in the sales_date table).
How is this done? I suspect that we can't use the date_dim table with the summary (due to the problems noted by the poster above). Do we have to create another table "month_dim"? Do we have to fold all of the desired date attributes (month, quarter, year) into the summary? Obviously we'd like to re-use all of the pertinent already existing date items (quarter, month, year, etc.), not recreate them over again, which would result in essentially two sets of items in the EUL. [One used for this month summary, and another used for the detail.]
I searched the forum - someone asked this same question back in 2000 - there was no answer provided.
The only other thought I have is to "snowflake" the date_dim into two tables and two folders, one at a date level, another at the month level. Then the detail tables can connect to date_dim (which is linked to month_dim), while the summary data can connect directly to month_dim.

JOIN 2 tables that have same column ?

I need to learn how to join two tables that both have the same column name:
tbl1 - idskey
tbl2 - idskey
the idskey column holds a id_number
When I do the JOIN I would like to make sure that only Distinct records are joined from both tables and that any duplicates are removed in the final join. So if:
Tbl1 has a idskey of: 12345
and
Tbl2 has a idskey of: 12345
In the final JOIN I want to remove one of those duplicates.
I actually need to join 3 tables that have the same linking column names for the join, but if I learn how to do this correctly on 2, that will be a start.
10g for db, thanks!

Hi,
SELECT DISTINCT and GROUP BY are the most common ways to get unique results from non-unique keys. Exactly how you use them depends on exactly what you want to do.
SELECT DISTINCT guarantees that no two rows in the result set, conisdering all columns, will be identical.
GROUP BY produces one row from a set of rows that have a common feature. The values on that row may be a composite of values from various rows in that set (e.g., an average).
Please post a small, specific example. For instance:
"I have two rows in tbl1 ...
and these fhtee rows in tbl2 ...
Notice how there is one row with idskey=12345 in tbl1 but two such rows in tbl2.
How can I get theses results ...
where only one row has idskey=12345?"

Joining a table with all_tab_columns

How is it possible to join a table with the tab_columns?
The query im trying to establish is that in my table they are 12 columns with months names. So under an input variable im trying to return the required values with the selected months. The only way i could think of to get the months to connect with the tab_columns table.
Any suggestion is really appreciated
SELECT bust,
Sum(jan) JAN,
Sum(feb) FEB,
Sum(mar) MAR,
Sum(apr) APR,
Sum(may) MAY,
Sum(jun) JUN,
Sum(jul) JUL,
Sum(aug) AUG,
Sum(sep) SEP,
Sum(oct) OCT,
Sum(nov) NOV,
Sum(DEC) DECC
FROM budget a,all_tab_columns b
WHERE vsl_code = 4602
AND code = 1
AND year=2013
AND account_code='30'
AND b.table_name='BUDGET'
AND b.column_name IN
                     (SELECT column_name
                      FROM (SELECT Column_name, ROWNUM r
                                    FROM all_tab_columns b
                                    WHERE table_name = 'BUDGET'
                                    AND Column_id BETWEEN 3 AND 14
                                    ORDER BY column_id)
                      WHERE r BETWEEN 2 AND 3 ) --Returns February,March
group by bust;

Sorry, I don't understand what you're trying to do or why you think you need to join to all_tab_columns. Perhaps you could post the definition of the budget table, some sample data, and the results you're hoping to see.
Without that, I don't see why you can't just do this:
SELECT bust,
Sum(jan) JAN,
Sum(feb) FEB,
Sum(mar) MAR,
Sum(apr) APR,
Sum(may) MAY,
Sum(jun) JUN,
Sum(jul) JUL,
Sum(aug) AUG,
Sum(sep) SEP,
Sum(oct) OCT,
Sum(nov) NOV,
Sum(DEC) DECC
FROM budget a
WHERE vsl_code = 4602
AND code = 1
AND year=2013
AND account_code='30'
group by bust;

Join two tables using union

Hi Gurus,
I have three tables. I want to join all tables using union in SQL statement. The query is returning all the records from both tables but i only require unique rows based on a specific column value. Here is my table structure -
TableA -
LIC_ID          NUMBER(10)     NOT NULL
LIC_NUMBER     VARCHAR2(20)
COMMENCE_DATE     DATE
EXPIRY_DATE     DATE
TERM          VARCHAR2(20)LIC_ID is the primary key in this table -
Sample data from TableA
LIC_ID          LIC_NUMBER     COMMENCE_DATE          EXPIRY_DATE     TERM
2          TR4323          12/04/2008          11/03/2010     2 Years
34          TR5432          23/07/2009          22/07/2010     1 Year
45          TR5321          24/06/2009          23/06/2010     1 Year
65          TR6666          23/07/2010          22/07/2011     1 Year
32          TR2423          30/05/2010          29/05/2011     1 YearTableB -
MAR_ID          NUMBER(10)     NOT NULL
LIC_ID          NUMBER(10)     NOT NULL
ZONE_NAME     VARCHAR2(20)
DEPARTMENT     VARCHAR2(20)
ACTIVITIES     VARCHAR2(200)
COMMENTS     VARCHAR2(200)MAR_ID is the primary key in this table and LIC_ID is the foreign key on TableA
Sample data from TableB -
MAR_ID          LIC_ID          ZONE_NAME     DEPARTMENT     ACTIVITIES     COMMENTS
23          2          ZONE A          IT          NONE
43          34          ZONE B          IT          NONE
33          65          ZONE C          ACCOUNT          NONE
          TableC
REC_ID          NUMBER(10)     NOT NULL
LIC_ID          NUMBER(10)     NOT NULL
DIST_NAME     VARCHAR2(20)
REGION          VARCHAR2(20)
ACTIVITIES     VARCHAR2(200)
COMMENTS     VARCHAR2(200)REC_ID is the primary key in this table and LIC_ID is the foreign key.
Sample data -
REC_ID          LIC_ID          DIST_NAME     REGION          ACTIVITIES     COMMENTS
2          45          SA          NORTH          NONE
3          65          TA          NORTH          NONE
5          32          NT          SOUTH          NONEHere is my sql query -
select a.lic_id, a.lic_number, a.commence_date, a.expiry_date from
TableA a, TableB b
where a.lic_id=b.lic_id
union
select a.lic_id, a.lic_number, a.commence_date, a.expiry_date from
TableA a, TableC c
where a.lic_id=c.lic_idThe above query returns -
lic_id          lic_number     commence_date          expiry_date
2          TR4323          12/04/2008          11/03/2010
34          TR5432          23/07/2009          22/07/2010
45          TR5321          24/06/2009          23/06/2010
65          TR6666          23/07/2010          22/07/2011
32          TR2423          30/05/2010          29/05/2011
65          TR6666          23/07/2010          22/07/2011     LIC_ID 65 exists in both table TableB and TableC hence it repeats in query but I want to display that only once. How can I do that? I want to return unique record on LIC_NUMBER.
Hope this make sence.
Many thanks,
Tajuddin

Thanks for all your reply and suggestions. David altering session did not work.
Sven your idea helped me to figure it out what to do. I found a way around to fix it. Here is my current code -
select a.lic_id, a.lic_number, a.commence_date, a.expiry_date from
TableA a, TableB b
where a.lic_id=b.lic_id
union
select a.lic_id, a.lic_number, a.commence_date, a.expiry_date from
TableA a, TableC c
where a.lic_id=c.lic_id and c.lic_id not in ( select lic_id from TableB)This will exclude any LIC_ID exists in TableB.
Thanks again for your help guys.
Regards,
M Tajuddin
Web: http://tajuddin.whitepagesbd.com
Blog: http://aspblog.whitepagesbd.com

Join multiple tables across separate databases

I needed to perform a join on multiple tables in two separate databases. I am using Sybase ASE 12.5 and jConnect 5.5 JDBC driver.
Table A is in DB1 and Table B is in DB2. Both DB1 and DB2 reside on the same database server.
I have set up JNDI bound datasources DS1 for DB1 and DS2 for DB2.
If the queries involved single tables or multiple tables within the same database, it is simple. But I am not seeing any way where I can perform a join between Tables A and B, which reside in separate databases. The datasources DS1 and DS2 are associated with DB1 and DB2 respectively, so I am not sure if there is anything like performing joins using two data sources.
One alternative I am facing is using a stored procedure in one database refer the table in the other database, for the join. But I may not be allowed to modify the database; currently, I am allowed to perform READ-ONLY queries.
So I am looking for any and all options. Please advice.
Thanks!

Two choices..
One find the syntax in DB2 that allows you to do what you want in there. That would often be somelike...
select a.myfield
from database1.table1 a, database2.table2 b
where a.id = b.id
Obviously the database itself must support this. If it doesn't then you have choice two.
You extract the data from database1 using java for table1.
You extract the data from database2 using java for table2.
You write java code that merges the data from both sources.

Three way join mapping

I have three tables file, file_location, and file_object as bellow:
file_location (file_id, file_system_id, stored_on,...)
file (file_id, name, object_id, file_size, ...)
file_object (object_id, created_on, ...)
I need to issue a query that do three way join, for example
SELECT floc.stored_on, mf.file_size, mo.created_on
FROM file_location floc, file mf, file_object mo
WHERE mf.file_id = floc.file_id
AND mo.object_id = mf.object_id
AND floc.file_system_id = 1
How can I avoid doing a separate query for each File and each FileObject(without writing custom SQL to produce some new view-object)?
I would expect the tool to be able to do this in three queries, one for each table, which are then linked up on the client side.
Does anybody know how to do this? I tried different approach including use join, but always end up with separated queries for each object.
Thanks

I'm am not clear on your object model, or the relations between File, FileObject and FileLocation, but in general to optimize queries in TopLink you can use batch reading, joining, partial object reading or report queries.
If you just want the three data values back, one from each object, you might be best off using a ReportQuery.
i.e.
ExpressionBuilder file = new ExpressionBuilder();
ReportQuery query = new ReportQuery(File.class, file);
query.addAttribute("fileSize");
query.addAttribute("storedOn", file.get("location").get("storedOn"));
query.addAttribute("createdOn", file.get("fileObject").get("createdOn"));
List result = (List) session.executeQuery(query);
To read the objects, assuming File has a 1-1 to FileObject and 1-1 to FileLocation, you could query for File and batch read FileObject and FileLocation.
i.e.
ReadAllQuery query = new ReadAllQuery(File.class);
query.addBatchReadAttribute("fileObject");
query.addBatchReadAttribute("fileLocation");
List result = (List) session.executeQuery(query);
If your are trying joining/batch reading and still getting separate calls please include your query definition. It could be that you have already read and cached these objects with value holders in them, or are not using indirection in general.

Need Help on Joining multiple tables in Golden Gate

Hi,
Can you please help me with some examples on joining multiple tables in Golden Gate. i.e, my requirement is to Join Table 1 & Table 2 in Source and Load it in Target with 10 fields from Table 1 & 5 fields from Table 2 based on the join condition between Table 1.key = Table2.key
I have been trying to do that using SQLEXEC command in Golden Gate. But, is there a way I can do this in the Extract parameter file?
Thanks for your time
Regards
Suresh

Hi,
Thanks a lot for the prompt reply. I am able to do that for the below scenario
Source.T1.Field1
Source.T1.Field2
Source.T2.Field1
Source.T2.Field2
Target Table
T1.Field1, T1.Field2, T2.Field1, T2.Field2.
But, if I already have T2.Field1 in T1 table, then T1.Field1 takes the precendence and getting loaded. i.e., I wanted to join the table 1 & Table 2 and based on the matching condition, I will need to populate the data either from T1 or T2.
Hope you got my requirement.
Below the Data Dump file & Replicat File.
EXTRACT dpump
USERID ********, PASSWORD ********
RMTHOST *******, MGRPORT 7809
RMTTRAIL /oracle/gg/dirdat/rt
--PASSTHRU
TABLE TABLE1,
SQLEXEC (ID LOOKUP,
QUERY "SELECT FIELD1 FROM SOURCE.TABLE2 WHERE FIELD1 = :v_field1",
PARAMS ( v_field1 = field1 )),
TOKENS (tk_field_1 = @GETVAL (lookup.field1));
Replicat file
REPLICAT repjoin
ASSUMETARGETDEFS
HANDLECOLLISIONS
USERID *******, PASSWORD ********
MAP SOURCE.T1, TARGET TARGET.GG_TABLE_T1,
COLMAP ( USEDEFAULTS ,
field1 = @token ("tk_party_id"));
I eventually wanted to join like below.
select t1.field1, t1.field2, t2.field1 from t1, t2
where t1.field1 = t2.field1;
Thanks for your time again
Regards
Suresh

Joining multiple tables in ssis

I have to join multiple tables like 10 of them and load the data into destination. I get like 66 million records after joining, I have tried two ways to joining and load the data. First way, I used SQL command in ole db source and wrote the query there but
this is taking forever to start, second way is used sort and merge join transformation and also used Issorted property where ever I can but as it requires multiple sort transformation it is time consuming.
Is there any other way I can load those 66 million records in less time??
Thanks,
sree

Hi sree,
If you want to load 66 million records to a SQL server database, the OLE DB Destination Editor allows us to choose either “Table or view” or “Table or view-fast load” from a drop down if data access mode is Table or View. “Table or view-fast load” is the
fastest way to load data to destination. It internally uses the bulk insert statement to send data into the destination table.
Besides, SSIS relies heavily on buffer. A set of records are read into the buffer, and from buffer they are written to the destination. So we can change two properties DefaultMaxBufferRows and DefaultMaxBufferSize to improve the performance. Also we can
add Conditional Split Transformation build some parallelism into the common data flow that directly load data to OLE DB Destination.
Reference:
http://henkvandervalk.com/speeding-up-ssis-bulk-inserts-into-sql-server
http://svangasql.wordpress.com/2012/04/10/simple-tips-to-speed-up-your-ssis-data-flow/
http://www.developer.com/db/top-10-methods-to-improve-etl-performance-using-ssis.html
Thanks,
Katherine Xiong
Katherine Xiong
TechNet Community Support

Joining two tables, sql query

This is a newbie question! I would like to join two tables. Table_1 contains xml stylesheets:
id stylesheet doc
1 <xml stylesheet doc A>
2 <xml stylesheet doc B>
And Table_2 contains the XML documents that the stylesheets will transform:
id XML doc
1 <XML document 1>
1 <XML document 2>
1 <XML document 3>
2 <XML document 4>
2 <XML document 5>
I would like <xml stylesheet doc A> to transform only XML doc that have an id of 1, so I tried this sql statement:
select a.stylesheet_doc ,b.xml_doc from Table_1 a, Table_2 b where a.id=b.id and a.id=1;
This statement returns the rows I want (stylesheet doc with id equals 1, and xml_doc with id equals 1), but it pairs each xml document with a style sheet.
stylesheet doc A <XML document 1>
stylesheet doc A <XML document 2>
stylesheet doc A <XML document 3>
My question is, is there a way to have a result that looks like this?
stylesheet doc A
<XML document 1>
<XML document 2>
<XML document 3>
That is, is there a way in sql to get rid of duplicate stylesheet doc A?
I have tried group by and rollup and xmlagg.
Thank you very, very much for your help.
Jim

Hi, Jim,
Welcome to the forum!
You just want to display the XML, not actually transform it, right?
GROUP BY ROLLUP should work, but I find it easier with GROUP BY GROUPING SETS. Here's an example from tables in the scott schema:
SELECT       CASE
          WHEN GROUPING (ename) = 1
          THEN d.dname
       END          AS dname
,       e.ename
FROM       scott.dept     d
JOIN       scott.emp     e ON     d.deptno     = e.deptno
GROUP BY GROUPING SETS ( (d.dname, e.ename)
               , (d.dname)
ORDER BY d.dname
,       ename          NULLS FIRST
;Output:
DNAME          ENAME
ACCOUNTING
               CLARK
               KING
               MILLER
RESEARCH
               ADAMS
               FORD
               JONES
               SCOTT
               SMITH
SALES
               ALLEN
               BLAKE
               JAMES
               MARTIN
               TURNER
               WARDYou may have noticed that this site noramlly compresses whitespace.
Whenever you post formatted text (such as query results) on this site, type these 6 characters:
\(small letters only, inside curly brackets) before and after each section of formatted text, to preserve spacing.

JOIN two tables and creat a new one

dear all,
as a newbie in Bw i have a question.
I worked already with other etl tools (powercenter) where there are objects to join 2 tables and create a new one to create a total transforming process to load a fact table.
In BW an INFOSET is the only thing to join 2 odssen. On this a query can be created.
BUT HOW TO JOIN 2 TABLES (= only ODS object?) AND CREATE A NEW TABLE FOR FUTHER PROCESSING ????
Regards,
Herman

hi jacobs, refer to these links particularly second one
http://help.sap.com/saphelp_erp2004/helpdata/en/92/43ec39d0383f09e10000000a11402f/frameset.htm
http://help.sap.com/saphelp_erp2004/helpdata/en/f1/713c3b
35703079e10000000a114084/content.htm
hope this clears ur doubt
Assigning points is the way of saying thanks in sdn
ravi

Why oh why, weird performance on joining large tables

Hello.
I have a large table cotaining dates and customer data. Organised as:
DATE CUSTOMER_ID INFOCOLUMN1 INFOCOLUMN2 etc...
Rows per date are a couple of million.
What I'm trying to do is to make a comparison between date a and date b and track changes in the database.
When I do a:
SELECT stuff
FROM table t1
INNER JOIN table t2
ON t1.CUSTOMER_ID = t2.CUSTOMER_ID
WHERE t1.date = TO_DATE(SOME_DATE)
AND t2.date = TO_DATE(SOME_OTHER_DATE)I get a result in about 40 seconds which is acceptable.
Then I try doing:
SELECT stuff
FROM (SELECT TO_DATE(LAST_DAY(ADD_MONTHS(SYSDATE, 0 - r.l))) AS DATE FROM dual INNER JOIN (SELECT level l FROM dual CONNECT BY LEVEL <= 1) r ON 1 = 1) time
INNER JOIN table t1
ON t1.date = time.date
INNER JOIN table t2
ON t1.CUSTOMER_ID = t2.CUSTOMER_ID
WHERE t2.date = ADD_MONTHS(time.date, -1)Ie i generate a datefield from a subselect which I then use to join the tables with.
When I try that the query takes an hour or two to complete with the same resultset as the first example.
THe only difference is that in the first case I give the dates literally but in the other case I generate them in the subselect. It's the same dates and they are formatted as dates in both cases.
Any ideas?
Thanks
Edited by: user1970293 on 2010-apr-29 00:52
Edited by: user1970293 on 2010-apr-29 00:59

When I try that the query takes an hour or two to complete with the same resultset as the first example.If you get the same results, than why change the query to the second one?
THe only difference is that in the first case I give the dates literally but in the other case I generate them in the subselect. It's the same dates and they are formatted as dates in both cases.Dates are dates,... the formatting is just "pretty"
This
select to_date(last_day(add_months(sysdate
,0 - r.l)))
from dual
inner join (select level l from dual connect by level <= 1) r on 1 = 1doesn't make much sense... what is it supposed to do?
(by the way: you are doing a TO_DATE on a DATE...)

N-way joins - interim table

Similar Messages

Maybe you are looking for