Store data in giant records?

[squaregoldfish]

We can do this for data reduction because it's calculated in one go, and not edited piecemeal.

I'm also tempted to store it compressed, but that may be a step too far. Look into best practice.

In fact, we could do the sensor values too - in practice they're often dealt with en masse. The only exception is setting QC flags, which are done down to one at a time and should be written immediately. There's also the 'split' QC for positions and external standards.