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ODI LKM using DB Link

KashSiddApr 16 2019 — edited Apr 16 2019

Hi,

I have the following Data Servers

Source: Oracle DB

Target: Oracle DB (This has the DB Link going to the Source)

I have been trying out the following LKMs but not being successful:

LKM Oracle to Oracle (DBLink)

LKM Oracle to Oracle Pull (DBLink)

LKM Oracle to Oracle Push (DBLink)

Which one should I use and which Data Server should I add the DB Link to?

BTW, it works when I use LKM SQL to Oracle but takes very long to load the data into the Target table.

ODI Version: 12.2.1.2.6

Frank Kulash

Answer

Hi,

When you say "CONNECT BY LEVEL <= x" , make sure at least one of the following is true:
(1) the table in the query has only one row, or
(2) you know what you're doing.

In other situations, create a Counter Table that has all the numbers you'll ever need, and join to the Counter Table where you otherwise would do a CONNECT BY.
In the definition for the Counter Table, the CONNECT BY clause will resemble your original CONNECT BY clause, but instead of "CONNECT BY LEVEL <= x" it will be "CONNECT LEVEL <= *(SELECT MAX (x) ...)* ".
When you use the counter table, the join condition will be similar to your original CONNECT BY condition.

WITH	cntr	AS
(
	SELECT	LEVEL	AS n
	FROM	dual
	CONNECT BY	LEVEL <= ( SELECT MAX (LENGTH (a_id))
			      	   FROM	  a
				 )
)
,	split_a_id	AS
(
	SELECT	  a.a_text,
--		  a.a_id,	-- For debugging only
--		  c.n,	-- For debugging only
		  SUM (TO_NUMBER ( SUBSTR ( a.a_id || '0'
	    	       	 	 	  , -c.n
					  , 1
					  )
				  )
	    	      ) OVER ( PARTITION BY  a.a_text
		      	       ORDER BY      c.n
			     )	AS cut_length
	FROM      a     a
	JOIN	  cntr	c	ON	c.n	<= LENGTH (a.a_id)
)
SELECT    SUBSTR ( a_text
	         , 1
	         , LENGTH (a_text) - cut_length
	         ) 	AS cut_text
FROM      split_a_id
ORDER BY  a_text
,     	  cut_text	DESC
;

Now that you're dealing with multiple rows, you need a PARTITION BY clause in the analytic SUM function.

Thanks for including the CREATE TABLE and INSERT statements.
Please format your code, and post it between

 tags so this site won't remove any spaces.
The link was a good idea, but it seems to be a link to the wrong thread.

Edited by: Frank Kulash on Nov 17, 2009 2:46 PM
Commented out 2 line I forgot to delete after testing.

Marked as Answer by Ludy · Sep 27 2020

Ludy

Thanks Frank Kulash,
now got better understanding in using the LEVEL in CONNECT BY.
Now things are getting clearer to me.

sure will post code between

 tags, and sorry about the link.

Aketi Jyuuzou

I like recursive with clause B-)
I do Not have Oracle11gR2
Therefore I made below solution using PostgreSQL8.4 :8}

CREATE TABLE TTT(ID text,Val text);
INSERT INTO TTT(ID,Val) VALUES('13233424','ABCDEFGHIJKLMNOPQRSTUV');
INSERT INTO TTT(ID,Val) VALUES('13233424','WXYZABCDEFGHIJKLMNOPQR');

with recursive rec(ID,Val,LV,cuts) as(
select ID,Val,1   ,substr(ID,1,1)    from TTT
union all
select ID,Val,LV+1,substr(ID,LV+1,1) from rec
 where LV < length(ID))
select substr(Val,1,(sum(cuts::integer) over(partition by Val order by LV))::integer) as CUT_TEXT
  from rec
order by Val,LV desc;

       cut_text
-----------------------
ABCDEFGHIJKLMNOPQRSTUV
ABCDEFGHIJKLMNOPQR
ABCDEFGHIJKLMNOP
ABCDEFGHIJKL
ABCDEFGHI
ABCDEF
ABCD
A
WXYZABCDEFGHIJKLMNOPQR
WXYZABCDEFGHIJKLMN
WXYZABCDEFGHIJKL
WXYZABCDEFGH
WXYZABCDE
WXYZAB
WXYZ
W

I like model clause solution too :D

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Added on Apr 16 2019

#data-integration

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