What do you mean by fixed and variable length row size?
The other thing is to think very carefully about partitioning options, do you want to maintain 642 partitions? Dont forget that partitions dont all have to be the same size, for time related data we use a combination of yearly partitions for old data and monthly partitions for newer data. Also consider archiving strategies you could use a larger but slower storage medium to archive off older data but have it still available. It also helps to automate the procedures for creating new partitins and archiving off older partitions.