GISquirrel uses its own metadata tables to define its feature classes and their behaviours. The tables are created automatically on first connecting to a database or importing any dataset, assuming the user has the required permissions.
In PostGIS the tables are created in the public schema, as they are system wide (like PostGIS functions). In SQL Server the tables are created in the dbo schema. Data tables, by contrast, can be located in any schema.
The tables are listed below, with links to more detailed information:
and optionally additional tables for attribute domains, created in the same schema as the owning spatial table: