Hold up ,- when I used a C or similar language for accessing a database and wanted to clamp down on memory usage to deterministically control how much I want to allocated, I would explicitly limit the number of rows in the query.

There never was an unbound "select all rows from some table" without a "fetch first N rows only" or "limit N"

If you knew that this design is rigid, why not leverage the query to actually do it ?

What am I missing ?