Why do we need to set Min pool size in ConnectionString

Question

For SQL connection pool, why do we need to set up a min pool size? As connections will be saved in the connection pool and reused, why do we need to keep live connections sp

Answer 1

why do we need to keep live connections specified by the min pool size

As you may know that connection creation is resource intensive job. So, you may chose to set this to a small number such as 5 if your application needs consistent response times even after it was idle for hours. In this case the first user requests won't have to wait for those database connections to establish. You can read the details of pooling here.