A key/value store is easy to build in Postgres, just define a table with a key column and a value column, that's it. Given that both key and value can be of dat

A key/value store is easy to build in Postgres, just define a table with a key column and a value column, that's it. Given that both key and value can be of datatype JsonB or BLOB, there's no restriction in generality, just, you know, aptness for the purpose. Now if you do that, you can—in Postgres—define additional structure or choose a different model entirely if your KV store turns out to be less ideal for whatever you want to do. MongoDB does not give you that choice.