<Li> Scalability features differ between vendors--some offer auto - scaling, others enable the user to scale up using an API, but do not scale automatically . There is typically a commitment for a certain level of high availability (e.g. 99.9% or 99.99%). </Li> <P> The design and development of typical systems utilize data management and relational databases as their key building blocks . Advanced queries expressed in SQL work well with the strict relationships that are imposed on information by relational databases . However, relational database technology was not initially designed or developed for use over distributed systems . This issue has been addressed with the addition of clustering enhancements to the relational databases, although some basic tasks require complex and expensive protocols, such as with data synchronization . </P> <P> Modern relational databases have shown poor performance on data - intensive systems, therefore, the idea of NoSQL has been utilized within database management systems for cloud based systems . Within NoSQL implemented storage, there are no requirements for fixed table schemas, and the use of join operations is avoided . "The NoSQL databases have proven to provide efficient horizontal scalability, good performance, and ease of assembly into cloud applications ." </P> <P> It is also important to differentiate between cloud databases which are relational as opposed to non-relational or NoSQL: </P>

Is sql also the standard interface in cloud based solutions