Summary from the doc:
This is a particularly messy aspect of most SQL implementations, so let’s settle on some terms first:
- Schema: a collection of named tables
- Catalog: a collection of named schemas (also known as a database)
This doc will attempt to describe a standards-compliant implementation for DataFusion, using Postgres’ design decisions as a guide where the standard is not prescriptive (due to our adoption of its query dialect).
As an example of how this works in practice, given a default catalog of “db” and a default schema of “public”, all these table references would be equivalent: