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In Part 2 where they start reading from the new table, what happens when old subscription data is not present in the new table? Do they then copy the data from
by ploggingdev 10y ago
In Part 2 where they start reading from the new table, what happens when old subscription data is not present in the new table? Do they then copy the data from the old table to the new table when the need arises?
- MBCook 10y agoYou have two options. The first is to not move to phase two until EVERY record is duplicated. Looks like that's what they did. The other option is the on-demand option you mentioned. The biggest issue I see is the latency to fetch that information is suddenly a lot more random. If it's not in DB B then you have to fetch from A and write into B before returning the information.