Oracle versus PostgreSQL or possibly MySQL -- maybe. But don't think Oracle sells snake juice; their reporting tools, for instance, are top-notch and way beyond what the open source world can provide.

I was more speaking to how easy it is to underestimate SQLite's flexibility and power and not realize how wide its use case actually is.

Of course for many use cases Oracle's tools are the best choice, but SQLite can handle quite a serious dataset in some use cases. A million records sounds like a lot. I can easily imagine crews used to working with Oracle using it for project far below its ideal capacity when they can buy licenses on a big corporate account.

So to me, the SQLite use case is often where the PRIMARY purpose of a database could be served nearly as well with fopen(), but where it's likely that there will be SECONDARY uses for which having a convenient universal access method would be useful.

I've even considered writing an external table plugin for SQLite to facilitate diagnostics and reporting of a complex ad-hoc file format I designed so I could get those benefits with a custom data structure; unfortunately, doing that seems somewhat complex in SQLite.

Well, that comment resonates with me. I feel the same but can't support it well with arguments. Care to share what you would use instead? F.ex. to replace fopen() with like the OP describes.

I've worked places where there is a rule that "The Corporate Database is Oracle and Oracle Only". Any mention of database _at_all_ will mean someone will ensure that The Corporate Database is used. It doesn't matter if Postgres or SQLite would be a cheaper/better choice.