Metatron Usecases

[sambi...@gmail.com]

Im new to metatron and just happened to see this ans on first impression, it looks cool. However i have a few questions on what use cases we can solve using this tool.

1. I have data available in MySql, S3, Mongo, ElasticSearch.
2. We want to provide analytics on top of these data with different drilldowns, charting, dashboarding across the data sources.
3. Ability to discover the datasets from each data sources and create a semantic layer view across those datasets on which we can fire sql queries with projections, filters, groupbys, joins. Etc.
4. Custom report creation on top of these datasets and scheduled reports to send as excel csv files.

When we fire sql queries then the query actually gets executed against source db or against Druid. In that case whatever datasets we want to query we have to ingest all of that to Druid first.

Do you support joins over different dataets in druid ?

Can we make druid store data in S3 or we need to have the data in local disk.

Regards
Sambit

[Mahesh Venkat]

Good questions ! I would love to get answers to these questions.

Can someone provide detail writeup on Join feature (limited) that was added to Metatron-druid? 

How does it work against multiple data sets

[Navis Ryu]

1. It's all done in broker (aka. not distributed)

2. Only supports equi-join (inner, left, right, full)

3. Uses sorted merge join or hash join based on row count of join aliases

4. Integrated to Druid SQL facility (see https://www.slideshare.net/navis94/running-tpch-on-druid-update)

thanks.