Oracle is a powerful, tunable, scalable and reliable industrial RDBMS. It provides some functionalities which are absent in simple freeware RDBMS like MySQL and PostgresSQL, such as: transactions support, concurrency and consistency, data integrity, partitioning, replication, cost-based and rule-based optimizers, parallel execution, redo logs, RAW devices and many other features. Although Oracle is a very functional database, the additional qualities like reliability impose some overhead. In fact, providing many advantages Oracle has some disadvantages. For example great tenability requires more experienced DBA, redo logs support provide great reliability against instance and media failures but requires more efficient disk system. I think you should select Oracle as a database for DataparkSearch if you want to search through hundreds of megabytes or several gigabytes of information, reliability is one of the primary concerns, need high availability of the database, and you are ready to pay higher sums for hardware and Oracle DBA to achieve better quality of service.