“Show me your flowcharts [code] and conceal your tables [data structures], and I shall continue to be mystified. Show me your tables, and I won’t usually need your flowcharts; they’ll be obvious.”
I think this quote misses that there can (and arguably should) be differences between your persistence model and your actual data structures. I'd argue that keeping things 1:1 with your underlying tables is incredibly restrictive and leads to models that miss out on the expressiveness that's available in modern languages.
I think the brackets were simply suggesting that flow charts are analogous to code and tables are analogous to data structures in that quote. Not that your tables and data structures in a concrete system will be the same.
-- Fred Brooks