| 1. | Efficiency and the bear : short sales and markets around the world
市场效率与熊市：卖空操作与全球股票市场 |
| 2. | That s a performance difference of five times faster due to one null assignment
那就是一行赋空操作产生的5倍的性能差距。 |
| 3. | Depending on the volume of data , you may need to run vacuuming for longer periods of time
根据数据量，您可能需要较长的一段时间来运行清空操作。 |
| 4. | If not , vacuuming might not have enough system resources to efficiently remove data
如果不是，清空操作所需的系统资源可能不足，无法有效删除数据。 |
| 5. | A calendar cleanup action lets you remove your calendar entries based on a user - specified cut - off date
日历清空操作可以根据用户指定的截止日期移除日历项。 |
| 6. | Stored procedure to determine when vacuuming last ran and how many events and notifications were removed
存储过程来确定上次运行清空操作的时间以及删除事件和通知的数量。 |
| 7. | The view returns only the current set of events , whereas the notification table contains all events that have not been removed via vacuuming
视图仅返回当前事件集，而通知表包含尚未通过清空操作删除的所有事件。 |
| 8. | But do note that the reason for this performance difference is because the variable is scoped incorrectly , for which the null assignment is simply a workaround , and also because the object is very large
但是请注意这个性能差别产生的原因是变量的作用域不正确，这正是赋空操作发挥作用的地方，并且是因为所创建的对象非常大。 |
| 9. | Verify that your rules are efficient , that you have the proper indexes defined on event and subscription data , that vacuuming is running to remove old data , and that the rules are not being blocked by other processes running on the server
验证下列各项：您的规则有效、您对事件和订阅数据定义了正确的索引、正在运行清空操作以删除旧数据，以及规则未被服务器上运行的其他进程阻塞。 |
