A branch dimension tracks the administrative region a branch reports to. Leadership only ever needs to compare a branch's current region against its immediately prior region for a single transition review, and they explicitly do not need full multi-version history. Which slowly changing dimension design fits this narrow requirement most efficiently?

Type 3 slowly changing dimensions add one or more columns to hold a limited amount of history, typically the immediately prior value, alongside the current value, on the same dimension row. This fits a requirement to compare only the current state against the one before it, without needing a full timeline of every past state. It is more compact than Type 2 for this narrow case, since there's no need to maintain multiple historical rows or effective-date ranges. Type 2, inserting a new row with full effective-date history for every past region, solves a broader problem than what's asked, tracking every historical state indefinitely, which adds modeling and query complexity leadership explicitly said it doesn't need here. Type 1, overwriting with no trace of the prior value, would fail the stated requirement outright, since leadership specifically wants to see the previous region, and Type 1 discards it entirely. A separate fact table dedicated to region-change events reframes a dimension attribute as an event stream, which is a heavier, differently structured solution than simply carrying a previous-value column, and it isn't the standard slowly changing dimension technique for this case. When choosing Type 3, confirm the business need truly never extends beyond one step of history, since a Type 3 design is difficult to extend if leadership later asks for the full sequence of regional changes rather than just the last two.