Recently a couple of different clients have asked me why it's necessary to take a snapshot of data (e.g., a member count) in order to track the history of data (e.g., comparing year over year membership counts). They ask: "Why can't we just query the data from last year?"

The answer? Because your AMS is a transactional database, data changes over time, which makes querying on historical data a challenge. Here's a good example:

A trade association has 500 organization members on January 1, 2022. In June of 2022, two members merge to become one new company. Those two company records are merged into one company record. Any time after that, when a query is run to count all members as of January 1, 2022, the count will now be 499 companies (because two records have been merged into one).*

Because the AMS is a transactional database, data is going to change over time. This is why historical queries can be inaccurate, and why snapshots are necessary.

So if you want to track history or make year over year comparisons, you'll need to take snapshots.

*And in case you're wondering, yes, this also applies to individual membership organizations!