AFAIK the each No in the Postgres column of the page you cited is still a No, although read-only databases can be effectively had by granting only select permissions on all tables in a database. However, there are many new features since 8.2. Some from 8.4:
- Windowing Functions
- Common Table Expressions and Recursive Queries
- Default and variadic parameters for functions
- Parallel Restore
- Column Permissions
- Per-database locale settings
...and some from 8.3:
- Full text search is integrated into the core database system
- Support for the SQL/XML standard, including new operators and an XML data type
- Enumerated data types (ENUM)
- Arrays of composite types
- Universally Unique Identifier (UUID) data type
- Add control over whether NULLs sort first or last
- Updatable cursors
- Server configuration parameters can now be set on a per-function basis
- User-defined types can now have type modifiers
...whether Firebird has these, I don't know.
