FerretDB: open-source MongoDB alternative
At one company we had one-off requests to run get some statistics from our mongodb.<p>Writing the proper queries proven pretty tricky whenever GROUP BY/JOINs were involved, so I used online converters between SQL -> mongo query.<p>But then I realized that PostgreSQL has nice JSONB type (supports indices for subfields). So I put all the mongo data into tables with a single JSONB column (or two columns id+data, if you prefer).<p>Turned out that was much faster to run analytical queries :)<p>"document" is just row<p>"collection" is just table