musings and one liners

When do you need ACID?

The recent JPMorgan Chase outage caused by an Oracle RAC block corruption places an old question back on the agenda that gets ignored way too often: How to tell whether you need ACID-compliant transaction integrity. The cost of ACID in large database systems is so high that you should consider moving those parts to simpler, cheaper or better scalable (or all three) systems that may not provide ACID compliance, but still store your data.

What kind of data? That would usually be data that can be rebuilt in time, or where it doesn’t matter if samples are lost, or some updates don’t happen in the same order. Never financial data or data that has to be correct for regulatory reasons.

What kind of systems store data but don’t provide ACID? NoSQL DBs primarily, but also all kinds of caches or even flat files…