Downsides of local buffer optimization
Local buffer optimization is not without its downsides. The most obvious one is that all objects with a local buffer are larger than they would be without one. If the typical data stored in the buffer is smaller than the chosen buffer size, then every object is wasting some memory, but at least the optimization is paying off. Worse, if our choice of buffer size is badly off and most data is, in fact, larger than the local buffer, the data is stored remotely but the local buffers are still created inside every object, and all that memory is wasted.
There is an obvious trade-off between the amount of memory we are willing to waste and the range of data sizes where the optimization is effective. The size of the local buffer should be carefully chosen with the application in mind.
The more subtle complication is this - the data that used to be external to the object is now stored inside the object. This has several consequences, in addition...
