> PipelineDB will become a standard, open-source PostgreSQL extension

What does this imply?

Not for streaming analytic workloads, because PipelineDB fundamentally adds continuous queries to PostgreSQL, so data is continuously distilled and aggregated as it arrives, before it is stored, which drastically reduces the amount of data stored in PipelineDB (or soon, in PostgreSQL via the extension refactor).

PipelineDB also offers a clustering extension for large workloads (see: http://enterprise.pipelinedb.com/docs/)

But in terms of ad hoc, exploratory analytics workloads, yes - the scaling limitations would be the same, since for ad hoc, exploratory analytics PipelineDB and PostgreSQL are the same. But with that said, the processed, aggregated data that gets stored is generally much smaller than large volumes of granular data, so there is much less data to comb through with PipelineDB.