Best schema design for product catalog management especially product features which are dynamic in structure.

Hi EveryOne,

I am looking for the support in designing the catalog system(schema design) especially product specifications.

I am planning to have Postgresql which supports json as well.

For product, category and the association is flat.

but when it come to the specifications those are dynamic and will change category to category and product to product how to handle.

how to handle enrichment and validations.