Are reflections *required* for relational database sources?

I’m new to Dremio, using Community Edition 1.4.4. I have created data source connections to SQL Server and MySQL. In both cases, it seems that I am required to define a reflection. If my understanding is correct, a reflection is a physical copy of the data. I want to go directly against the original sources, so I don’t want a reflection.

However, if I set “Acceleration - Refresh Policy” to 0, I get an error message: “Reflection refresh must be at least 1 hour.”

Is it possible to define relational sources without any form of caching?


Yes, reflections are totally optional. The parameter in the source dialog is in case you decide to define a reflection, but unless you define one, this parameter won’t be used, and source will be queried directly.

Many thanks for this quick response!

Hi Laurent - I need to Query an Elastic search index which is created on a daily basis. Is there any way i can Schedule a job say every 4 hours so that the query runs and pulls the data from index at specified interval.

is it a new question, unrelated to the current topic? Make sure to open a new topic next time so it’s easier for people to find answers for similar questions. As for now, Dremio has no way to run a query periodically, but that should be something easy to do with an external tool connecting to Dremio.