2.4 Database Systems 

There are quite a few Open Source database systems available; MySQL and PostgreSQL are 

the most popular ones. For smaller applications, both database systems are a stable, no cost 

alternative to commercial database systems; however, their architectures show distinct 

differences. Therefore, it is important to weigh the advantages and disadvantages of both 

systems, and select the database that is most applicable for a given purpose. The 

characteristics of both systems are outlined below. 

MySQL is available at 

http://www.mysql.com

, PostgreSQL at 

http://postgresql.readysetnet.com

. 

License information can be obtained at: 

http://www.mysql.com/doc/L/i/Licensing_and_Support.html

 for MySQL, 

http://postgresql.readysetnet.com/devel corner/docs/postgres/ln1274.html

 for PostgreSQL. 

Feature 

MySQL V3.23 

PostgreSQL V7.1 

License 

MySQL Free Public License (very restrictive  License of the 

for Open Source standards; e.g. a license 

University of California 

needs to be purchased for applications 

(unproblematic 

requiring MySQL to function) 

licensing) 

Kernel architecture 

Multi threaded allowing for utilization of 

Single threaded 

multiple CPU's 

Transactions with 

Not supported 

Supported 

rollbacks 

Views Not 

supported 

Supported 

Sub selects Not 

supported 

Supported 

Foreign keys 

Not supported 

Supported 

Extendable type system  Not supported 

Supported 

Stored procedures 

Not supported 

Supported 

Size limitations: 

Table size 

2GB to 8TB (operating system dependent) 

64TB (all O/S) 

Row size 

65534 (without BLOB's) 

Unlimited 

Columns/table 

3398 

1600 

Table 3: Comparison of MySQL and PostgreSQL Features 

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