Schema change challenges

[michielbdejong]

While reading this exciting list of schema change challenges it occurred to me that a single system changing its schema over time may not be so different from a network of multiple systems with competing schemas.

Especially if you start out with one system, then add a second one, and only require data portability from the first to the second, it's almost exactly the same problem as writing a script to migrate data from an "old" to a "new" database schema.

[michielbdejong]

The changes that happen to the code in live programming may be quite similar to the changes happening to the network as a whole in a data portability network.

[michielbdejong]

• 43

• 44

• 45

• 46

• 47

• 48

[michielbdejong]

I made a start with #43 to get my head around the problem space. I pushed some code to the main branch but added a note to the readme explaining this is just draft scribbles, nothing to see yet.

I might go straight to #48 since it's generic but also quite specific in its examples of code/state changes to support.