azure - SQL Azure 兼容性级别会影响性能吗？

Question

我有一个兼容级别为 100 的 V11 数据库。

我有一个兼容级别为 120 的 V12 数据库。

a) 100 是什么意思？

b) 如果我将 V11 上的兼容性级别更改为 110，会影响性能吗？

b) 如果我将 V12 上的兼容性级别更改为 110，会影响性能吗？

Answer 1

您可以获得有关兼容性级别的详细信息 here 。本质上，这是为了兼容以前版本的 SQL。为了回答你关于性能的问题，我想引用 MSDN 文章中的这一段:

Compatibility level affects behaviors only for the specified database, not for the entire server. Compatibility level provides only partial backward compatibility with earlier versions of SQL Server. Starting with compatibility mode 130, any new query plan affecting features have been added only to the new compatibility mode. This has been done in order to minimize the risk during upgrades that arise from performance degradation due to query plan changes. From an application perspective, the goal is still to be at the latest compatibility level in order to inherit some of the new features as well as performance improvements done in the Query optimizer space but to do so in a controlled way.

希望这有帮助!西尔维娅·杜姆拉