Not really. Heavier and lightweight usually refer to the amount of features and requirements of a piece of software.
In that regard, it's easier to see which of PostgreSQL and SQLite is lighter. PostgreSQL requires a separate process running with its own config, plus the library to communicate with it, plus all the things Postgres does... On the other hand, SQLite is just a library that reads files in a certain format.
> It solves more problems than SQLite and “lightweight” is not really a concrete benefit for SQLite.
But it is a concrete benefit. Sometimes you'll have restricted environments because either by power or by permissions, you can't install Postgres or any other database server (e.g., mobile phones or embedded software). Or sometimes you just don't want the user to configure their postgres instance and your software for just a few tables (e.g., system utilities/small services that just need a simple database).
In that regard, it's easier to see which of PostgreSQL and SQLite is lighter. PostgreSQL requires a separate process running with its own config, plus the library to communicate with it, plus all the things Postgres does... On the other hand, SQLite is just a library that reads files in a certain format.
> It solves more problems than SQLite and “lightweight” is not really a concrete benefit for SQLite.
But it is a concrete benefit. Sometimes you'll have restricted environments because either by power or by permissions, you can't install Postgres or any other database server (e.g., mobile phones or embedded software). Or sometimes you just don't want the user to configure their postgres instance and your software for just a few tables (e.g., system utilities/small services that just need a simple database).