global unique identifier for 2 tables in relational sql There are 2 sub-systems[ suppliers and retailers ] in our online market chain management system . Entry in any of those[ suppliers or retailers ] should give a globally unique ID .There would be listing and filtering of each system based on category , locations , nearest retailers .

FYI : The query for listing retailers or suppliers is already complex which uses lots of joins and unions. So, I don't want another table for handling Unique ID .
There is another option to combine retailers and suppliers entry in 1 table.
But chances are there it may soon run out of entries if I combine retailers and suppliers entry in 1 table

Individual business entities[retailers or suppliers] have there own accounting system ,product management system , cost management system . So its a bit complex system and some of the query operations are already slow.
I have checked the possible solutions but it wouldn't satisfy our needs because of performance reasons and complexity.
What should I do , should I go for NoSQL , would it solve the problem  or Is there any other solution
If your requirement is to have global Unique identified for across Entities, you can go for UUID. For more details refer here