One Lookup table data read multiple times tp apply different joins
Hi, I have one lookup table data in my job and the lookup data volumn is very huge. hence the requirment is executes the one lookup table data once and in tmap source table join conditions is different times. the reason is same lookup table data compare to different input condtions based on getting diiferenct column value. Is talend possible lookup data value read multiple time in tmap transformation? Thanks, Regards, Srinivasan S
I know this is a month or so late but I've had almost exactly the same problem, this is how I solved it, it would be nice if you could use treplicate to do this as you can get some funny behaviour with tHash's with nested jobs and can be quite memeory intensive but when it does work it can be very quick.
tHashInput and tHashOutput are in the technical section of the pallete although you may need to turn them on.
You can alias the lookup table. We had a requirement where columns c1,c2,c3,c4,c5 and c6 of table A have references on column p of Lookup table L i.e. Multiple columns from table A have references to single column in lookup table L.
We achieved by alisaing the lookup table 6 times and connecting all the aliases and the source to tmap and it worked fine without any issues.
regards,
Jeevan Anaparthy
ETL Architect
CSC, Chennai
You can alias the lookup table. We had a requirement where columns c1,c2,c3,c4,c5 and c6 of table A have references on column p of Lookup table L i.e. Multiple columns from table A have references to single column in lookup table L. We achieved by alisaing the lookup table 6 times and connecting all the aliases and the source to tmap and it worked fine without any issues.
regards, Jeevan Anaparthy ETL Architect CSC, Chennai
Since I have exactly the same requirement, I'd like to know what "aliasing a table" means and how it can be achieved in talend?!
EDIT:
I think I know what was meant but it's not the best solution in my oppinion.
I have the following problem
SourceTable
Error Code 1 | Error Code 2
100 | 200
200 | 200
300 | 100
100 | 200
Now I have a ErrorCode Dimension with all the possible Codes (about 10000). Now, if I use two tMap Components and two tDbInput's (from the same Dimensiontable) each Component hats to load the 10000 Codes, what takes a while. Any Alternatives?
