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It sounds good in theory. In practice, I haven't heard much around running backwards migrations on a data warehouse / massive collection of events but I'm sure
by tedmiston 9y ago
It sounds good in theory. In practice, I haven't heard much around running backwards migrations on a data warehouse / massive collection of events but I'm sure some out there already do it.
- dkersten 9y agoI suppose one needs to take care that migrations are never lossy so that the full information for upgrading or downgrading a version is available.
- tedmiston 9y agoYeah, that's the challenge. For instance, how do you handle when a column was one data type but then down the road was changed to another type when the two aren't cross compatible or could potentially break?
- raulk 9y agoYou could retain this info in a meta field of flexible type. For a DB, it could a JSON type. For messages, it could be an extra _meta field on the message that the systems themselves ignore.