Good examples of a scalable database include; NoSQL database, MySQL, Microsoft SQL.
<em>Remember</em>, these databases are called scalable databases because they support memory expansion without a measurable performance decrease.
For example, if the management of a hotel notices that its 1 terabyte computer used to store its security videos is no longer adequate to meet the hotel's expansion, then decide to buy a newer server that can be integrated into the current system. We can say they just applied the concept of scalable databases.
In design phase developers make prototypes. The prototype is the solution without actual implementation. That prototype is shown to the user for the purpose of getting feedback. So design phase of SDLC involves making improvements based on user feedback.
