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18 Do You Still Use a Database?

Wednesday, 29 October – 11:00-11:45

Thursday, 30 October – 12:00-12:45

Klaus Wuestefeld, Objective Solutions, klaus@objective.com.br

This is the demo of Prevayler, the original free-software Prevalence layer for Java.

System Prevalence is transparent persistence and transparent replication of native business objects. Prevayler makes any old Java VM logically invulnerable for business objects without the need for pre or post-processing.

Queries run 3 to 4 orders of magnitude faster than using a database through JDBC even with the whole database cached locally in RAM.

DBMSs are the single most hampering force acting on the OO community. While they provide us with vital services, such as the babies born inside the Matrix, we are also pitifully atrophied by the restrictions they impose.

Instead of maiming our object design, Prevalence frees us to use the observer pattern among thousands of business objects or to run polymorphic queries on millions of them - some basic examples that would be way too slow, even on OO databases.

We are no longer restricted to the query language, algorithms and data-structures provided with our database.

Prevayler has been ported to several languages including Python, Perl, C#, Objective C, Ruby and a Smalltalk port by Kent Beck and friends.

Witness the transparent persistence and replication of an application running on Prevayler and discuss:

  • The simple concepts that make it possible;
  • The 350 lines of insanely refactored Prevayler source-code;
  • The shortcomings of the technology;
  • The adoption by the community.

Above all, you'll be able to shutdown your database and start using the full potential of OO.

Keywords: Prevalence, Persistence, Transparent.