Spring '10 is just around the corner, with many great new features. One of the Apex Code enhancements which caught my attention was the limits on the number of items a collection can hold has been removed. The previous limit was set at 1000. Add this to the new ability to use generic sObjects to create a collection and Collections within the platform just got a whole lot more powerful.
As Ben Parker, the o-so-wise uncle of Peter Parker (aka Spiderman) once said: "with great power comes great responsibility." Changes to Collections is no different, and require some new thinking in regards to best practices.
The release notes, for example, mention that there is still a limit on heap size so care must be taken to not load up a collection and hit this limit. Good news is that a few other other Spring '10 changes can certainly be used to ensure you design your applications as efficiently as possible.
Here are just a few new SOQL clauses and functions which can be used with collections to help make the most fo the changes.
This is certainly not a complete list, but should certainly be something every developer is familiar with.