If XMLQUERY is used within a SELECT statement, the PASSING clause can refer to either a table column or a stored procedurevariable.
如果在select语句中使用XMLQUERY，那么passing子句可以引用表列或者存储过程变量。
2
As mentioned previously, this variable is automatically generated for each procedure.
如前所述，这个变量将针对每个过程自动生成。
3
This variable specifies the size (in 4 KB pages) of the pool used for fenced routine invocations, such as stored procedure or user-defined function calls.