Had to validate data before a migration.
Part of the data was in Postgres,
part was sitting in a Parquet dump.
Usually this turns into:
export → upload → load → query
Did it like this instead:
<pre><code>SELECT u.id, u.email, e.event_type

FROM postgres.users u

JOIN &#x27;events.parquet&#x27; e

 ON u.id = e.user_id
</code></pre>
No export, no loading step.
Saved a lot of time.
Curious how others handle this kind of cross-source checks?

Dmitry Narizhnykh

A quick workflow tip for querying Postgres and Parquet files together without the usual export-upload-load cycle. By using DuckDB's ability to join a live Postgres table directly with a local Parquet file in a single SQL query, data validation before migrations becomes much faster and simpler.

No export, no load: querying db + parquet together