Your docs section is useless…

Talking about this

You cover whole bunch of some advanced topics but you forgot to mention basics:: SYNTAX

Is it SQL/json or f* what !!!

And you charge money for this?? What?!

!!!

There is no reason to behave this way on an internet forum. Redash is offered for free as an open source product. If you have constructive feedback to share I’m sure the community would gladly accept it.

With regard to your question, there is a prominent section on the page you linked entitled Query Syntax:

Query Syntax

In most cases we use the query language native to the data source. In some cases there are differences or additions, which are documented on the Querying Data Sources page.

This is also reiterated throughout the getting started guides. If you feel this is not clear enough you could propose an alternative. So far it has not been an issue for tens of thousands of users.