Define a PartiQL-System

[RCHowell]

Motivation

he PartiQL Specification briefly mentions a database environment which is akin to a single catalog and schema, but we have yet-to-define fundamental system concepts such as catalogs, schemas, information_schema, and the SQL PATH. These concepts govern all current PartiQL functionality (table and function resolution), developing functionality such as DDL/DML, as well as future functionality such as views.

We are motivated to make clear the relationship between PartiQL and SQL in regards to catalogs and schemas; but are motivated to relax some SQL restrictions to make PartiQL adaptable to systems which do not strictly adhere to the SQL specification. This adapatability comes from relaxing the fixed hierarchy (catalog > schema > table) of SQL systems to be UNIX-like with arbitrary filesystem hierarchies. We have found this structure to better fit real-world systems which either lack schemas or nest schemas. Note that schema here means "collection of database entities: tables, routines, triggers, etc." rather than the type description of a table. For this reason, we will disambiguate the term and call these collections scopes rather than schemas.

This RFC focusses on the catalog and execution semantics of name resolution; it does not include other topics such as transactions, recovery, access control, or constraint enforcement.