topic Re: Json Parsing extremly slow in Talend Studio

Json Parsing extremly slow

lucaL — Tue, 16 Sep 2025 17:42:20 GMT

Hi all,

I woul like to ask you if to parsing a really simple JSON String should take between 5 and 10 second wit tExtractJsonFields component.

I have this really simple json:

{ "c1": "55665", "c2": 1757610940000, "c3": 381685, "c4": "28006354", "c5": 1774479600000, "c6": { "c61": "5", "c62": "N", "c63": 0, "c64": 60, "c65": 60 } }

This is passed to a subjbob via context variables, so the subjob has a tFixedFlowInput that transform the context to a flow, then a tExtractJsonFields with "$" as Jsonpath query and a $.c1...c5 + $.c6.c61...c65 query for extracting each field. So the job continue with a tmap in order to compute couple of fields, and a tFileOutputDelimited to write out this row on a csv file.

Now, the time it takes to make this process is about 5 to 10 second, each time the job is called... I have another job that process a json with java code and the json.org library, and in 5 seconds it process hundreds of rows... This is the picture of the job:

So, the question is: am I making something wrong? is there something I can do to speedup the processing?

Thanks,

Luca

Re: Json Parsing extremly slow

Dave_Simo — Tue, 16 Sep 2025 19:57:29 GMT

hello @lucaL

It's strange that it takes 5 seconds, I reproduced the parsing of your json and it takes 0.09s

Best Regards

Re: Json Parsing extremly slow

Denis_Segard — Wed, 17 Sep 2025 06:38:21 GMT

Hello,
When you say it takes 5 seconds , do you refer to the exec time ?

Kind regards
Denis

Re: Json Parsing extremly slow

lucaL — Thu, 18 Sep 2025 15:55:48 GMT

Hi all, thanks for the replies. After some other investingation I have found that the long time was not due to the json parsing, but to the fact that the subjob making the parser was called by a dynamic trunjob, hence the longer time was due to the compilation of the job, and not for its execution! Thanks all, and sorry for the post 🙂