How does Athena prepare a cluster of compute nodes for a specific query?

Shared Regional Cluster: This refers to the overall pool of compute resources available within a specific AWS region. All users in that region share this pool. Think of it as the total available infrastructure that Athena can draw from. This can also be referred to as the "regional compute pool" or "regional resource pool."

Query-Specific Cluster: When you run a query, Athena temporarily allocates a subset of nodes from the shared regional cluster to form a dedicated cluster for your query. This is tailored to the specific needs of your query, such as its complexity and data size. Once the query is completed, these resources are returned to the shared pool. You can also refer to this as the "dedicated query cluster" or "dynamic query cluster".