AWS Aurora DB max_连接

我不是一个数据库专家,但我可以试着从我的理解来回答你的问题。

1) 每月45便士?

No, the max_connections is not per month but the number of concurrent
connections allowed simultaneously.

Connection could either be a query or you trying to manually enter into the
database.

Since for a query to read/write into the database, it needs to open a
connection to the DB, hence it is also counted as one connection, as something
(read here as a piece of code)is connected to your database. It is the same thing
as you opening a client, typing username/password etc and entering into the DB.

3) 如果是一个查询,那么如果一个查询返回100个值呢?这些算是连接吗?

The value returned by the query doesn't matter. It can return as many values as it 
like(you need to handle that in your code though). What happens in the code is that
you open a connection and then run a query after that you close that connection.
What happens between when the connection open and closes doesn't affect the number
of connection.

However you need to take care of other parameters while running a long query into a
database. As it could spike your CPU/memory utilization etc. but the number of
connection per query would still be 1.