什么是“大数据库”？

没有一个阈值，其中一个小的，中型和大型的数据库是为我们的SQL新手？小数据库变为中等或中等数据库变大。一般来说，当我听到这些术语时，我认为所存储的总记录数量是特别大的。

There isn't a threshold where a small database becomes medium or a medium database becomes large. Generally, when I hear these terms, I think of particular orders of magnitude in terms of total records being stored.

• 小：10 ⁵ 条记录。


• 中：10 ⁵ 至10


• 大：10 ⁷ 至10 ⁹ sup> 9 或更大数量的记录。

• Small: 10⁵ or fewer records.
• Medium: 10⁵ to 10⁷ records.
• Large: 10⁷ to 10⁹ records.
• Very large: 10⁹ or greater number of records.

建议使用海报 le dorfier ，您还可以根据每种类型的属性数据库有。以这种方式分类，我会说：

As poster le dorfier suggested, you could also think about it in terms of the properties each kind of database has. Categorizing it this way, I'd say:

• 小：性能不是一个问题。您的查询运行正常，无需进行任何特殊的优化。

• Small: Performance is not a concern. Your queries run fine without making any special optimizations. You see only a marginal performance difference when using front-line enhancements like indexes.

中：您的数据库可能有一个或多个工作人员分配到兼职对其维护和护理。这些人注意数据库的健康;他们的主要管理职责是防止不可接受的性能问题，并尽可能减少停机时间。

Medium: Your database probably has one or more staff that are assigned part-time to its maintenance and care. These people pay attention to the database's health; their primary administrative responsibility is to prevent unacceptable performance problems and minimize downtime.

大：可能有专门的工作人员并提高性能，以及确保应用程序更改不会在数据库的生命周期中导致模式损坏。密切监视有关数据库的健康状况和状态的指标。

Large: Probably has dedicated staff member(s) whose job is to work on the database and improve performance, as well as make sure that application changes don't cause schema breakage over the lifetime of the database. Metrics about the health and status of the database are monitored closely. Significant expertise is required to understand and perform optimizations.

非常大：数据库存储大量必须随时可用的信息。性能优化是绝对需要在每个查询的每一盎司的速度，而没有它，数据库将不太可用，甚至不可能使用。数据库可能使用复杂或创新的复制或聚类技术，推动了当前技术的边界。

Very large: The database stores vast amounts of information that must be readily accessible. Performance optimizations are absolutely required to wring every last ounce of speed out of each queries, and without it, the database would be much less usable or even impossible to use. The database may be using sophisticated or innovative replication or clustering techniques, pushing the boundaries of current technology.

是完全主观的，并且某人可能很好地具有完全合法的大的替代定义。

Note that these are entirely subjective, and that someone may very well have a perfectly legitimate alternate definition of "large".