It first runs one or more queries against your DataSources in a drill-across query fashion. You can think of DataSources as one or more completely separate databases. You could have one mysql, one postgresql, one duckdb etc all in the same Warehouse (not saying this is common in production, just an example). Within those DataSource queries it's also joining all needed tables together for you, i.e. joining multiple tables in each database to meet your required grain.
It then takes the results of all those queries and combines that data in another layer which is currently an in-memory sqlite database. The purpose of that layer is joining the data for presentation as well as applying some additional features like rollups, technicals, formula fields, etc.
I'm not familiar with what superset does under the hood or exposes as an API so I don't know how to compare it, if there is some similar backend piece. But I suspect no part of superset is quite the same as this, based on what its front end can do.
It first runs one or more queries against your DataSources in a drill-across query fashion. You can think of DataSources as one or more completely separate databases. You could have one mysql, one postgresql, one duckdb etc all in the same Warehouse (not saying this is common in production, just an example). Within those DataSource queries it's also joining all needed tables together for you, i.e. joining multiple tables in each database to meet your required grain.
It then takes the results of all those queries and combines that data in another layer which is currently an in-memory sqlite database. The purpose of that layer is joining the data for presentation as well as applying some additional features like rollups, technicals, formula fields, etc.
I'm not familiar with what superset does under the hood or exposes as an API so I don't know how to compare it, if there is some similar backend piece. But I suspect no part of superset is quite the same as this, based on what its front end can do.
Happy to answer any other questions you have.