7. Scalability

You can easily scale up or scale down an SQL database or managed instance, either automatically or manually. There are two types of scaling: vertical and horizontal.

Vertical scaling refers to switching to a higher or lower service tier or vertically partitioning data, which is done to store different schemas on different databases.

Horizontal scaling refers to dividing data from a single table into different individual databases.

This chapter will teach you how to autoscale SQL databases and shard a database. The chapter also talks about how to run cross-database queries.

By the end of this chapter, you will be able to:

• Perform vertical and horizontal scaling.
• Create and maintain SQL database shards.
• Run cross-database elastic queries.
• Scale a managed instance.

This chapter covers how to vertically and horizontally scale your system to optimize the performance of your application.