limitation of rdbms-:We can easily see that in the changing scenario of web, advance and complex applications requirements are not easily satisfied by traditional RDBMS. Following are the limitations of RDBMS due to which it is required to enhance it and equip it with new features :
1. Model Value Based Rather than Entity Based -: RDBMS represent the data by a tuple of values where the values may change over time. There is no direct representation of real would entities as the representation of entity may be split over several relations. due to limitation of normalization attributes of an entity can have only atomic values. Besides this, there is no way to distinguish two entities with same values for all the columns.
2. RDBMS-: RDBMS does not support complex values advance applications like CAD, CAM as they require not just atomic values but also various forms of complex values like bulk values, (set, lists, bags…) structured values or set of structured values. These applications also require database to store multimedia objects like text, images etc.
3. Limited Operational Support-: RDBMS provides fixed rather than extensible set of operations to deal with application specific types of data. RDBMS also faces the difficulty in handling recursive queries which is required for many advanced applications RDBMS has limited form of constraints and constraint handling methods. So it is difficult to support many business rules by RDBMS.
4. Limited Support for Application Programming-: RDBMS proves to be good for short transaction and modularity. It also have impedance mismatch problem. Application programming also requires more application/business logic in the database to store and manage code in DBMS.
5.Limited support for work process -: RDBMS prove to be good for short transaction rather then long. It typically focus on a avoiding conflict between the process rather than supporting cooperation’s between them. Beside this there is no support for version, various variants and configuration management RDBMS also has limited support for schema evolution. RDBMS are poor at navigational access as like movement between individual records.
There are two main factor that lead users to adopt object database technology. Firstly a relational database becomes cumbersome to use with complex data as mentioned above. Secondly data is generally manipulated by application software written using object oriented programming language and the code needed to translate between this representing of the data and the tuples of a relation database can be tedious to write and time consuming to execute.