MySQL is the world's most popular open source database. With its proven performance, reliability, and ease-of-use, MySQL has become the leading database choice for web-based applications, used by high profile web properties including Facebook, Twitter, YouTube, and all five of the top five websites*. Additionally, it is an extremely popular choice as embedded database, distributed by thousands of ISVs and OEMs.

• Relational Database Management System (RDBMS): MySQL is a relational database management system.
• Easy to use: MySQL is easy to use. You have to get only the basic knowledge of SQL. You can build and interact with MySQL with only a few simple SQL statements.
• It is secure: MySQL consist of a solid data security layer that protects sensitive data from intruders. Passwords are encrypted in MySQL.
• Client/ Server Architecture: MySQL follows a client /server architecture. There is a database server (MySQL) and arbitrarily many clients (application programs), which communicate with the server; that is, they query data, save changes, etc.
• Free to download: MySQL is free to use and you can download it from MySQL official website.
• It is scalable: MySQL can handle almost any amount of data, up to as much as 50 million rows or more. The default file size limit is about 4 GB. However, you can increase this number to a theoretical limit of 8 TB of data.
• Compatibale on many operating systems: MySQL is compatible to run on many operating systems, like Novell NetWare, Windows* Linux*, many varieties of UNIX* (such as Sun* Solaris*, AIX, and DEC* UNIX), OS/2, FreeBSD*, and others. MySQL also provides a facility that the clients can run on the same computer as the server or on another computer (communication via a local network or the Internet).
• Allows roll-back: MySQL allows transactions to be rolled back, commit and crash recovery.
• High Performance: MySQL is faster, more reliable and cheaper because of its unique storage engine architecture.
• High Flexibility: MySQL supports a large number of embedded applications which makes MySQL very flexible.
• High Productivity: MySQL uses Triggers, Stored procedures and views which allows the developer to give a higher productivity.

SQLite is an in-process library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. The code for SQLite is in the public domain and is thus free for use for any purpose, commercial or private. SQLite is the most widely deployed database in the world with more applications than we can count, including several high-profile projects.

• Transactions are atomic, consistent, isolated, and durable (ACID) even after system crashes and power failures.
• Zero-configuration - no setup or administration needed.
• Full-featured SQL implementation with advanced capabilities like partial indexes, indexes on expressions, JSON, and common table expressions. (Omitted features)
• A complete database is stored in a single cross-platform disk file. Great for use as an application file format.
• Supports terabyte-sized databases and gigabyte-sized strings and blobs. (See limits.html.)
• Small code footprint: less than 500KiB fully configured or much less with optional features omitted.
• Simple, easy to use API.
• Fast: In some cases, SQLite is faster than direct filesystem I/O
• Written in ANSI-C. TCL bindings included. Bindings for dozens of other languages available separately.
• Well-commented source code with 100% branch test coverage.
• Available as a single ANSI-C source-code file that is easy to compile and hence is easy to add into a larger project.
• Self-contained: no external dependencies.
• Cross-platform: Android, *BSD, iOS, Linux, Mac, Solaris, VxWorks, and Windows (Win32, WinCE, WinRT) are supported out of the box. Easy to port to other systems.
• Sources are in the public domain. Use for any purpose.
• Comes with a standalone command-line interface (CLI) client that can be used to administer SQLite databases.

SQL Developer supports the following core features when migrating from Microsoft SQL Server:

• Automatically converts column data types to appropriate Oracle data types.
• Automatically resolves object name conflicts, such as conflicts with Oracle reserved words.
• Parses and transforms T-SQL stored procedures, functions, triggers, and views to Oracle PL/SQL.
• Provides advanced customization capabilities such as the ability to change data type mappings, delete and rename objects.
• Generates reports about the status of the migration.
• Generates the DDL scripts for the creation of the destination Oracle database.
• Generates scripts for data movement
• Displays informational, error, and warning messages about the migration in a progress window.

PostgreSQL is a general purpose and object-relational database management system, the most advanced open source database system. PostgreSQL was developed based on POSTGRES 4.2 at Berkeley Computer Science Department, University of California.

PostgreSQL was designed to run on UNIX-like platforms. However, PostgreSQL was then also designed to be portable so that it could run on various platforms such as Mac OS X, Solaris, and Windows. PostgreSQL is free and open source software. Its source code is available under PostgreSQL license, a liberal open source license. You are free to use, modify and distribute PostgreSQL in any form. PostgreSQL requires very minimum maintained efforts because of its stability. Therefore, if you develop applications based on PostgreSQL, the total cost of ownership is low in comparison with other database management systems.

• User-defined types
• Table inheritance
• Sophisticated locking mechanism
• Foreign key referential integrity
• Views, rules, subquery
• Nested transactions (savepoints)
• Multi-version concurrency control (MVCC)
• Asynchronous replication

• Native Microsoft Windows Server version
• Tablespaces
• Point-in-time recovery