topic How to do left-outer join and right-outer join in a single read? in Talend Studio

How to do left-outer join and right-outer join in a single read?

Anonymous — Mon, 26 Oct 2015 07:47:27 GMT

I have two input files. One is a main, the other is a look-up. Is there any way to do a left-outer join and a right-outer join without reading the input files twice?

Re: How to do left-outer join and right-outer join in a single read?

Anonymous — Mon, 26 Oct 2015 08:14:21 GMT

Hi
No, you have to do the join two times, and merge the two result, filter the duplicated rows. With a small data set, you can read the data only one time from the files and store them into memory first, read them from memory when doing join. eg:
tFileINputDelimited1--main--tHashOutput1
|
tfileInputDelimited2--main--tHashOutput2
|
onsubjobok
|
tHashInput1--main--tMap--.....
|
lookup
|
tHashInput2

Best regards
Shong

Re: How to do left-outer join and right-outer join in a single read?

Anonymous — Mon, 26 Oct 2015 08:40:01 GMT

Thanks for the quick reply!

However, I'm dealing with 5 million+ rows of data. Any best approach that you can suggest without compromising on the performace?

Re: How to do left-outer join and right-outer join in a single read?

Anonymous — Tue, 27 Oct 2015 05:39:42 GMT

No other way can achieve it with best performance, you have to read the data two times.