facility allows you to stipulate that connections that are no longer needed are not deleted immediately, but are kept free for a certain period of time. If a new connection to the data source is needed in that period, the free connection can be used for this purpose.
功能用于规定不立即删除某些不再需要的连接，而是将它们保留一段时间。如果在这段时间内需要新的数据源连接，则可以重新使用这些空闲的连接。