Following are few key features of the oracle database.
Real Application Cluster (RAC)
Data Guard for standby database
Virtual Private Database
Automatic Memory, Storage and Undo Management
OLAP, Partitioning, Data Mining
Advance Queuing, XML DB, Support for Spatial data
Flashback Database, Query, Table and Transaction
MySQL :- It is one of the most widely used open source RDMS.
Following are few key features:
Written in C and C++.
MyISAM storage uses b-tree disk tables with index compression for high performance.
Support for partitioning and replication.
Support for Xpath, full text search.
Support for stored procedures, triggers, views etc.,
SQLite:-SQLite does not work like a traditional client-server model with standalone process. Instead, it is a self-contained, server-less SQL database engine.
Main Features of SQLite:
Zero configuration with no setup or admin tasks.
Complete database is stored in a single disk file.
No external dependencies
Supports database of several TB in size
Work on most *nix flavors, Mac OS X, windows. It's also cross-platform.
WinCE is supported out-of-the box
SQL Server:- If you are buliding microsoft apps then it will be better to go with SQL Server as there is quick support provided and performance is better of SQL Server with microsoft apps.