SPIKE: Investigate extra queries / performance regressions imposed by snapshots

[unclecheese]

While the database writes are fairly well contained, there are a number of areas in the lifecycle of a snapshot where expensive queries are run, often in loops or recursive functions. We should do a thorough analysis of what could be done to mitigate some of the performance issues and how they scale with large ownership structures.

Acceptance criteria

• We have a firm understanding of the cost that snapshots imposes relative to vanilla versioned
• We have enough information to make a decision on whether performance enhancements are worth investing in