Whats the biggest namespaces config You have tried or seen being used? Considering it for a product that will have 168 different infosystems with own namespace and each has a lot of Tuples, and some may have around million object and million subjects. Do You think it will perform if DB is ok? Or no way, and probably needs splitting up for smaller portions, where some business logic has to make a choice, what instance of Keto has 144-th infosystem data? Also as understood, namespace is hot reloaded, so if all used as one, adding new infosystem namespace will cause some delay to system performance or no differenece?

it depends primarily on the database, so if it can handle it, keto will be able as well

But do You have some rough numbers that You know has been used or tested as a namespace and as a object - tuples - subject combo?

it is basically impossible to say... if you through enough resources at the db, and spin up numerous instances of keto, you can scale as you want probably depends also on how many data are stored vs how many are requested at any time