ion that the engineer designs. The RDBMS has no way to bind behavior to objects. This must be done through convention and represents a large opportunity for introducing errors. The data model produced by the software engineer during the analysis and design phase of project may be directly and simply mapped to an OODBMS' schema. With a RDBMS, data abstractions must be decomposed into a set of tables that conform to the normal forms of the relational rules. There's also an impedance mismatch between the way that data is available through a RDBMS verses an OODBMS. An engineer working with a RDBMS works in SQL; that is all access to information managed by the database is framed in the context of SQL. SQL is an excellent way to work with data on an ad hoc basis, but a developer wants the information in terms of the data abstractions that were identified in the analysis and design phase of the project. This is not possible using the SQL access afford by an RDBMS. A developer working with an OODBMS directly sees the same data abstractions in the database that were identified during analysis and design. No queries are used. This gets back to the fact that objects managed by an OODBMS appear to an application developer in a seamless fashion. OODBMS directly support reuse through inheritance. This concept is absent from a RDBMS. Commercial grade container libraries and other third party class libraries may be easily stored in OODBMS. This is not possible with a RDBMS. All of these differences between OODBMS and RDBMS result in a real and sizable productivity gain for developers working with OODBMS. Fault Tolerance Conventional RDBMS deal with fault tolerance issues and high data available with hardware based solutions. An example is the use of RAID technology to guard against media failure. These options are also available to an OODBMS. OODBMS that are based on peer to peer technology are designed without any single point failures. These systems are setup to degrade gracefully. If part of the distributed information store is not available, then the remaining information may still be accessed. These systems are more resilient to catastrophic failures.