The memory usage for the queryResultCache is significantly less than that of the filterCache because it only stores document IDs that were returned to the user by the query. 在queryResultCache的内存使用情况明显小于在filterCache,因为它只存储文档由查询返回给用户的id。
An expression whose value is passed to the dynamic SQL statement, or a variable that stores a value returned by the dynamic SQL statement. 体现其价值是通过的动态SQL语句或存储一个变量的值传回的动态SQL语句。
It stores the result sets returned by the database in RAM, as is. 它会在RAM中按照原样保存数据库返回的结果集。