What would a Database Diagram (ER Diagram/Table Layout) look like for measuring distribution of something?

Question

If I was, for example, going to count "activities" across many computers and show a rollup of that activity, what would the database look like to store the data?

Simply this? Seems too simple. I'm overthinking this.

ACTIVITYID  COUNT
----------  -----

Answer 1

If the volume is not going to be ridiculously large, I'd probably create a table that logs each event individually, with a DateTime as @Turnkey suggests, and possibly the machine that logged it, etc.

LOGID (PK)  ACTIVITYID  SOURCE  DATELOGGED
----------  ----------  ------  ----------

That would give you the ability to run a query to get the current count, and also to use the data to determine events in a time period, and/or coming from a specific machine. A clustered index on ActivityID should give you good query performance, and the table is narrow so inserts shouldn't be too costly.

Answer 2

I think that the actual activity would create some type of record with at least an ActivityId and ActivityDate in a logging table. An other column might be the identifier of the computer creating the log entry.

You would then create the count by aggregating the activity records over a specified time period.

Metro.