We have a requirement to follow responses for last 180 days, but our Interaction History is stored only for 90 days. If we create IH summary aggregate for last 180 days, will it store the data eventually over the 180 days or will it always be only for last 90 days?
In fact, Yes you can. A materialized IH Summary can be created over 180 days even if the retention policy of IH is only 90 days. This is because the IH summary is updated the moment the response is received. However, if you need to recreate the IH summary at some point in the future then only the 90 days of available data will be used which means they will lose some data in the recreated aggregate.
I don’t think this is documented anywhere. I just know because I asked our LDA and he knows how the summaries work in the backend. Basically, an IH summary or any aggregate can be materialized or not materialize. Materialized means there’s a real-time aggregation service running that updates the aggregate record with any new events processed. This aggregated data is stored in Cassandra. Non materialized means the aggregate is a simple query that runs at runtime to create the aggregated record from the db tables, but this can be much slower and is not advised. If the materialized IH summary doesn’t get corrupted or doesn’t need to be recreated for other reasons it can continue to maintain aggregations for any duration up to 999 days. When it is recreated it can only use whatever data is available in the source typically a db table which may not hold all historical data.