why are noSQL databases more scalable than SQL? [closed]

Question

Recently I read a lot about noSQL DBMSs. I understand CAP theorem, ACID rules, BASE rules and the basic theory. But didn't find any resources on why is noSQL scalable more easily than RDBMS (e.g. in case of a system that requires lots of DB servers)? I guess that keeping constraints and foreign keys cost resources and when a DBMS is distributed, it is a lot more complicated. But I expect there's a lot more than this.

Can someone please explain how noSQL/SQL affects scalability?

Answer 1

It really depends on your problem, each database type has its advantages and nether SQL nor noSQL is better at scaling, they are different. It all depends on the data you have and if your data is relation in nature then SQL may be better, if your data is document based (no defined schema) then noSQL may be better. We use both types of databases in our product, we have lots of different data and some fits into SQL and some into noSQL.

What kind of scale are you considering? Parallel access, handling large number of queries or very large data handling? Your question is very broad, it's a bit tough to answer without knowing what problems you are trying to solve.