I recently joined a new company and the development team was in the progress of a project to rebuild the database categories structure as follows:
我最近加入了一个新公司，开发团队正在一个项目的进展中重建数据库类别结构如下:
if we have category and subcategory for items, like food category and italian food category in food category. They were building a table for each category, instead of having one table and a link to the category id.
如果我们有类别和子类别的项目，如食品类别和意大利食品类别的食品类别。他们为每个类别构建了一个表，而不是一个表和一个到类别id的链接。
Now we have a table called food and another table called food_italian and both tables contain the same fields.
现在我们有一个名为food的表和另一个名为food_italian的表，这两个表都包含相同的字段。
I have asked around and it seems that some DBA prefers this design. I would like to know why? and how this design can improve the performance?
我问过周围的人，似乎有些DBA喜欢这个设计。我想知道为什么?这个设计如何提高性能?
2 个解决方案
#1
2
First, the most obvious answer is that you should ask them, not us, since I can tell you this, that design seems bogus deluxe.
首先，最明显的答案是，你应该问他们，而不是我们，因为我可以告诉你，设计似乎是虚假的豪华。
The only reason I can come up with is that you have inexperienced DBA's that does not know how to performance-tune a database, and seems to think that a table with less rows will always vastly outperform a table with more rows.
我能想到的唯一原因是，您有经验不足的DBA，他们不知道如何对数据库进行性能调优，并且似乎认为，行数少的表总是比行多的表好得多。
With good indices, that need not be the case.
有了良好的指数，情况就不必如此了。
#2
0
There are more than one way to do anything.
做任何事都有不止一种方法。
The possible benefit I see in doing the food, food_italian... is that it allows for table partitioning. Using many different tables allow for better table locking mechanism if you are using myisam.
我在做食物、吃意大利菜时看到的可能的好处……它允许表分区。如果使用myisam，使用许多不同的表可以实现更好的表锁定机制。
#1
2
First, the most obvious answer is that you should ask them, not us, since I can tell you this, that design seems bogus deluxe.
首先，最明显的答案是，你应该问他们，而不是我们，因为我可以告诉你，设计似乎是虚假的豪华。
The only reason I can come up with is that you have inexperienced DBA's that does not know how to performance-tune a database, and seems to think that a table with less rows will always vastly outperform a table with more rows.
我能想到的唯一原因是，您有经验不足的DBA，他们不知道如何对数据库进行性能调优，并且似乎认为，行数少的表总是比行多的表好得多。
With good indices, that need not be the case.
有了良好的指数，情况就不必如此了。
#2
0
There are more than one way to do anything.
做任何事都有不止一种方法。
The possible benefit I see in doing the food, food_italian... is that it allows for table partitioning. Using many different tables allow for better table locking mechanism if you are using myisam.
我在做食物、吃意大利菜时看到的可能的好处……它允许表分区。如果使用myisam，使用许多不同的表可以实现更好的表锁定机制。