This works surprisingly well. I end up just doing both - having one table store the blob, and another with the copied values (shopify_sales, shopify_sales_json

This works surprisingly well. I end up just doing both - having one table store the blob, and another with the copied values (shopify_sales, shopify_sales_jsonb). Databases are generally pretty good at handling large BLOBS/off-page heap values, but I prefer not to tempt the fates of buffer pool management.