Posts tagged decoupling
Extreme Decoupling in SQL – Select and DML against a table that is not a table at all
0One of the key objectives – though not ulterior motives – in Service Oriented Architecture is decoupling. By decoupling currently mutually dependent agents, we introduce more opportunity for flexibility, no-impact optimization, reuse and interoperability. This does not require Web Services and the world of WS* to realize. Even with fairly simple database means, we can establish some nice decoupling. Right here in SQL.
This article introduces a rather thorough case of decoupling. An example of executing a SQL Query that does not hit a table. The query addresses a View and returns data, without ever touching a table. The View supports DML and will reflect the results of the DML in subsequent queries. However, no table is used at all. The View is a complete decoupling mechanism that absorbs the query, turns it into a PL/SQL call and returns the results from PL/SQL. Through an Instead Of trigger, it does the same thing for DML. So when you are looking for decoupling – and you ought to be – look no further than to this simple, straightfoward View example.
Xenogenetics for PL/SQL: Infusing with Java Best Practices and Design Patterns (presentation at OOW 2010)
0Xenogenetics for PL/SQL: Infusing with Java Best Practices and Design Patterns – Alex Nuijten and Lucas Jellema
PL/SQL is a venerable programming language that is both vital and very much alive. This session will discuss how we further rejuvenate and enhance the way we create PL/SQL programs. We’ll tap into the world of .NET, Java, and other modern programming language to do some cherry picking: what are the very best practices, concepts, and design patterns and how can we apply them to PL/SQL? We’ll explain and demonstrate dependency injection, the observer pattern based on listeners, aspect-oriented programming (AOP), the decorator and template pattern, use of user-defined nested types, and collections.PL/SQL is a venerable programming language that is both vital and very much alive. This session will discuss how we further rejuvenate and enhance the way we create PL/SQL programs. We’ll tap into the world of .NET, Java, and other modern programming language to do some cherry picking: what are the very best practices, concepts, and design patterns and how can we apply them to PL/SQL? We’ll explain and demonstrate dependency injection, the observer pattern based on listeners, More >
Event based Decoupling in PL/SQL – your first Advanced Queue adventure
1Back in 2004 when we started with the AMIS Technology Blog, my main objective was to record the things I infrequently do in order to have notes describing the steps to go through whenever I needed to do the thing again. I was own primary audience, so to say. Over the years, the articles have increased in complexity and sometimes in absurdity too. This one is back to that original intention. This article is not fancy at all – even though it touches upon a powerful (and underrated) subject: the Advanced Queue in the Oracle RDBMS. For the 1000s of database developers and architects that make frequent use of AQ, I am not going to add anything: this article merely shows the steps for creating an Advanced Queue, how to register a listener on the queue and how to publish a message on the queue. That is not fancy at all, obviously.
What is extremely fancy and powerful – and not nearly used enough – is the architectural pattern that AQ allows us to introduce. Queues are a key concept for achieving decoupling. Decoupling itself is like the holy grail of architects – because it allows agility and reuse. Through a Queue, a publisher (or discoverer) of events can make them available to More >
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