> Not really, there is information_shema where they get everything they need to know about structure separately from data. But these tables of metadata are acc

> Not really, there is information_shema where they get everything they need to know about structure separately from data. But these tables of metadata are accessed as a graph (usually with plenty of cycles, and iteratively by following relations from specific objects of interest) and the result is a "hypertext" (usually presented as tables or as diagrams of objects) of tables, columns, indices, users, grants etc.