topic Re: tHashInput/Output usage in Talend Studio

tHashInput/Output usage

Alpha549 — Fri, 15 Nov 2024 21:32:54 GMT

Hello everyone,

tHashInput and tHashOutput components are not directly accessible. To make them accessible, we need to modify the project properties.

I have several questions :

1) Why aren't these components accessible from the start ?

2) I usually use CSV files to transfer data between sub-jobs and save these data in case of errors, etc. Could I use tHash components instead (let's assume that I don't want to store this data on the disk) ?

3) The cache memory is limited, so are these components recommended ?

Thank you for your experience

Re: tHashInput/Output usage

Anonymous — Tue, 25 Jul 2023 06:19:35 GMT

Hello,

By default, the technical components tHashInput and tHashOutput (and some other components) are not visible in the Palette. This is expected and it is a design behavior as described in the Talend Studio Component Reference Guide, Technical Components section.

For more information, please have a look at this documentation:

https://help.talend.com/r/en-US/8.0/technical/where-can-i-find-thashinput-thashoutput-components

For question 2 and question 3, It depends on your job requirement and the point of using thashinput/tHashInput is to store the result of the first Subjob (input) in memory (cache).

Hope it helps.

Best regards

Sabrina

Re: tHashInput/Output usage

Alpha549 — Tue, 25 Jul 2023 09:47:24 GMT

Hello @Xiaodi Shi

Thank you for your reply.

For my question 3), as cache memory is small, I understand that these components must not be used in case of a large amount of data.

Re: tHashInput/Output usage

Anonymous — Wed, 26 Jul 2023 04:08:44 GMT

Hello,

You'd better store temporary data on disk rather than in memory if you are using a large amount of data, as buffer components will consume a large amount of memory. This will optimize our job performance and avoid OutOfMemory Exception.

Best regards

Sabrina