Is it possible to use a single field with multiple, return separated values to form a relationship? For example, assuming I want to track a set if unique customer id's as "cohorts." I could create a separate record to hold each customer I'd and use another field to hold a cohort I'd. Or, I could use a single record for each cohort and store all customer id's in a single field.
Is it possible to use either technique? If so, should the list be return separated or comma delimited?
Are there strong reasons to use one approach or the other?