David Goodenough wrote on 20.06.2010 11:08:
> I don't support anyone has written a "how to write database agnostic
> code" guide? That way its not a matter of porting, more a matter of
> starting off right.
I don't believe in "database agnostic code".
In the end it basically means that the application will run equally slow on all platforms.
I'm not necessarily talking about syntax features/differences (e.g. hierarchical queries or other advanced features)
butabout behavioral features that stem from the way the engine works, e.g. due to different locking strategies or
differentoptimizers.
Some engines don't like single large transactions, some don't like a lot of small transactions.
Then think about syntactically identical statements that will behave differently because each engine has different
optimizationstrategies. Some engines are better with complex joins and subqueries some are better with several small
queries.An index that might be used in one engine to speed up a select might be totally ignored by another.
Thomas
