Methods and systems for managing large write-once tables are described. In some embodiments, a relational database management system includes a space allocation module that utilizes both a logical space allocation scheme, as well as a physical space allocation scheme, to allocate space in units (e.g., pages) having two different sizes—small pages and big pages. For instance, small pages are logically allocated with a conventional converter module, which manages a converter table for mapping logical pages to physical pages, while big pages are physically allocated with an object directory manager, which manages big objects comprised of big pages.