Talend Open Studio Big Data - Iterate and load multiple files in DB - talend

Question

I am new to talend and need guidance on below scenario:
We have set of 10 Json files with different structure/schema and needs to be loaded into 10 different tables in Redshift db.
Is there a way we can write generic script/job which can iterate through each file and load it into database?
For e.g.:
File Name: abc_< date >.json
Table Name: t_abc
File Name: xyz< date >.json
Table Name: t_xyz
and so on..
Thanks in advance

Answer 1

With Talend Enterprise version one can benefit of dynamic schema. However based on my experiences with json-s they are somewhat nested structures usually. So you'd have to figure out how to flatten them, once thats done it becomes a 1:1 load. However with open studio this will not work due to the missing dynamic schema.
Basically what you could do is: write some java code that transforms your JSON into CSV. Use either psql from commandline or if your Talend contains new enough PostgreSQL JDBC driver then invoke the client side \COPY from it to load the data. If your file and the database table column order matches it should work without needing to specify how many columns you have, so its dynamic, but the data newer "flows" through talend.
Really not cool but also theoretically possible solution: If Redshift supports JSON (Postgres does) then one can create a staging table, with 2 columns: filename, content. Once the whole content is in this staging table, INSERT-SELECT SQL could be created that transforms the JSON into tabular format that can be inserted into the final table.
However, with your toolset you probably have no other choice than to load these files with 1 job per file. And I'd suggest 1 dedicated job to each file. They would each look for their own files and triggered / scheduled individually or be part of a bigger job where you scan the folders and trigger the right job for the right file.