推荐使用 EXFMT 格式解释输出文件，因为它提供帮助此类 SQL 优化所需的信息。
The EXFMT format for the explain output file is recommended, because it provides the needed information to help such SQL optimization.
当不使用选项进行调用时，工具通常会输出语法帮助的内容，以帮助您获得可能需要的网格运行时信息。
When invoked with no options, a tool will typically print the contents of its syntactical help, which will can assist you in obtaining the grid runtime information you might need.
List To Group映射帮助将整个员工信息映射到输出步骤中的单一列表。
The list to Group projection helps in mapping the entire employee information to a single list in the output step.
应用推荐