Is it a good approach to use MariaDB in one Server and MongoDB in another one to store various client's data?
The reason I need MongoDB is because the client has to create custom Maintenance Checklist (which mean he has to create rows and columns), and then submit these data based on specific period. And I am finding hard time how to design this on MariaDB, even with dynamic columns since it might bring performance issue.

I'm very unsure If I understand...

Maintenance Checklist - you have a set of options.

You want to use mongodb because the options are dynamic?

Is parsing of the JSON document necessary - to eg create an aggregation?

Not sure if I got it right, but if I got, many to many relations model should solve this.

This sounds like a relational data set to me.

Where's MongoDB come into this?

Postgres can do both json and relational data. Why not use that?

@irene *cough* so does mariadb😅

Any modern database can.... Yes. Even SQLite. ;) *evtl laugh*

@C0D4 Oh I didn’t know. I basically haven’t dealt with it since it was called MySQL. And not all modern database stuff is equal. MS SQL Server was a requirement for a previous project hosted in OpenShift and we got stuck with MS licensing fees if we wanted to use a pod’s whole resources. We couldn’t scale to more than two pods without problems with read write. Distributed DB problems in excess.

So now the philosophy is “we know that Postgres scales, can be distributed, and does what we need”. Generally we don’t mess around with other DB engines unless the customer dictates a technical decision.

@irene yea mariadb 10.2 introduced json support, although I haven't had a reason to actually dive in, I rarely use json as data, there's been a few cases I've done it but the data isn't queried it's extracted and used as is.

https://mariadb.com/kb/en/...