SQL*Net more data from client The server is waiting on the client to send more data to its client shadow process, in an already initiated operation.
Oracle服务器等待客户端发送更多的数据
这个等待事件基本上是最常见的一个等待事件。 当一个会话建立成功后，客户端会向服务器端发送请求，服务器端处理完客户端请求后，将结果返回给客户端，
并继续等待客户端的请求，这时候会产生SQL*Net message from client 等待事件。
很显然，这是一个空闲等待，如果客户端不再向服务器端发送请求，服务器端将一直处于这个等待事件状态。
The cause of this event was a sequence of parse calls that passed excessively long SQL text strings through SQL*Net from the client to the server
(instead of using stored procedure calls to accomplish the same thing).
The long SQL text strings wouldn’t fit into a single SQL*Net packet, so the Oracle kernel spent a considerable amount of time awaiting second and subsequent SQL*Net packets during parse calls.
这个原因是一些列的解析请求传递了过长的SQL文本窜通过SQL*Net from the client to the server,（可以用存储过程完成同样的事情)长的SQL文件窜不能放到单独一个 SQL*Net packet,所以Oracle内核花费了大量的时间等待第二次及以后的SQL* Net的数据包
Wait Time: The time waited depends on the time it took to receive the data (including the waiting time)
等待时间依赖于花费在接收数据的时间
A shadow process is also called a server process in documentation. Oracle processes are either background processes such as DBWn, PMON, or server processes
which look like
$ ps -ef | grep LOCAL
oracle 10492 1 0 May 03 ? 0:01 oracleprod (DESCRIPTION=(LOCAL=no)(ADDRESS=(PROTOCOL=BEQ)))
oracle 10482 1 0 May 03 ? 0:05 oracleprod (DESCRIPTION=(LOCAL=no)(ADDRESS=(PROTOCOL=BEQ)))
oracle 28774 1 0 01:15:59 ? 2:41 oracleoprd (LOCAL=NO)