Do I need PostgreSQL if I plan to store some JSON plus normal tables?

Not necessarily.

If your app needs to store:

• normal relational tables
• plus some JSON documents / blobs of semi-structured data

then PostgreSQL is a very good fit, but it’s not required.

When PostgreSQL makes sense

Use PostgreSQL if you want:

• strong relational features for normal tables
• built-in JSONB support
• querying/filtering inside JSON
• transactions and data integrity across both relational and JSON data
• one database for both structured and semi-structured data

When you might not need it

You may not need PostgreSQL if:

• you’re just storing JSON as opaque text and never query inside it
• your current DB already handles JSON adequately
• you want a document-first database instead
• your data model is mostly simple and you don’t need relational features

Common options

• PostgreSQL: best “hybrid” option for tables + JSON
• MySQL/MariaDB: can also store JSON, but PostgreSQL is usually stronger for advanced querying
• SQLite: okay for small/simple apps, but less ideal for heavier JSON querying and concurrency
• MongoDB: better if the data is mostly document-based and relational tables are not important

Rule of thumb

If you expect to:

• join tables,
• enforce constraints,
• and still query JSON fields,

PostgreSQL is usually the simplest and most capable choice.

If you want, I can help you choose between PostgreSQL, MySQL, SQLite, and MongoDB based on your exact use case.