我要感谢IBM多伦多实验室的数据库顾问PaulYip，因为他提供了很有价值的帮助和设计建议。
I would like to thank Paul Yip, database consultant with the IBM Toronto Lab, for the much-valued help and design suggestions
本文说明了数据库设计和访问数据库的PHP代码中出现的五个常见问题，以及在遇到这些问题时如何修复它们。
This article illustrates five common problems in database design, in the PHP code that accesses databases, and how to fix these problems when you see them.
当您设计缓冲池时，您应该考虑数据库的内存需求。
When you design buffer pools, you should consider the database memory requirements.
在应用程序开发阶段，使用这个数据库服务器实例进行数据库设计、开发和调优。
During the application development phase, you will use this database server instance to design, develop, and tune the databases.
例如，它讨论逻辑和物理数据库设计。
For example, it discusses logical and physical database design.
现在，您需要大致了解为什么要选择这种有些奇特的数据库设计方法。
Now, you need to briefly understand why one might take this quirky approach to database design.
它具有星形或雪花形的维数据库模式设计。
It has a star or snowflake-like dimensional database schema design.
要实现这个目标，应当全面了解数据库设计和应用程序。
To achieve that goal, you need a thorough understanding of the database design and applications.
该信息转换成逻辑的(或物理的)数据库设计。
This information gets transformed into a logical (or physical) database design.
数据库设计的经验表明，模式作为避免编程错误的防护措施很有用。
Experience with database design shows that schemas are most useful as a safeguard against programming errors.
应该先进行数据库的规划和设计，然后才能实际创建数据库和表。
You want to plan and design for your database before you actually go ahead and create the tables.
数据库模型：封装供此特定项目使用的逻辑和物理数据设计。
Database model: Encapsulates a logical and physical database design for this specific project.
这简化了存储估算，进而简化了物理数据库设计。
This simplifies the storage estimate that eases the physical database design.
非模态设计程序提供了同时设计多个数据库对象的灵活性。
Non-modal designers allow you the flexibility to simultaneously work on designing several database objects.
考虑应用程序和数据库的性能特性的时机是在那些应用程序和数据库的初期设计阶段，也就是开发过程的开始阶段。
The time to consider the performance characteristics of applications and databases is during the initial design of those applications and databases, at the beginning of the development process.
如今，很多应用程序的数据库层都设计为存储过程。
Many applications nowadays design their database layer as stored procedures.
他们还需要掌握数据库的概念或具有DBA的经验，以便在设计解决方案时能够理解源和目标数据库之间的蕴涵关系。
They also need to have knowledge of database concepts or DBA experience in order to understand the implications for the source and target database when designing this solution.
前一节所描述的数据库设计决策的益处。
The benefit of the database design decisions described in the previous sections.
所有这些功能共同允许您通过调整数据库来配合业务环境，而不是牺牲您的设计来适应数据库。
All these features allow you to adapt the database to your business environment instead of compromising your design to fit the database.
许多因素都可以影响数据库服务器的性能，例如硬件系统的设计、数据库对象的设计、数据存储器的管理、应用程序的设计等等。
Many factors can affect the performance of a database server, such as hardware system design, database object design, data storage management, application design, and so forth.
本节介绍了一组数据库设计建议，可为存储和分析PDB数据提供一种简单而高效的数据库支持。
This section describes a set of database design recommendations that lead to simple and efficient database support for storing and analyzing PDB data.
当包含数据库时，此项活动识别出要在数据库中保存的设计元素，并设计相应的数据库。
When databases are involved, this activity identifies the design elements to be saved in a database and designs the corresponding database.
逻辑数据模型用来创建设计数据库所需的蓝图。
Logical data models are used for creating the blueprint needed to design your database.
数据库开发人员——负责实际运行的数据库，包括设计数据库、模式、表、表关系、索引，以及对查询进行优化。
Database developer — Responsible for the actual databases in operation, including designing databases, schemas, tables, table relationships, and indexes as well as optimizing queries.
虽然数据库应用程序的性能会受许多因素影响，但是我们着重讨论配置而不是诸如容量规划、数据库设计或应用程序设计之类的因素。
Although performance of a database application can influenced by many factors, we focus on configuration rather than on such things as capacity planning, database design, or application design.
数据库设计是高度可配置的。
您可以用很多的方式创建数据库设计、数据库访问和基于数据库的PHP业务逻辑代码，但最终一般以错误告终。
You can create database design, database access, and the PHP business logic code that sits on top of it in any number of ways, and you often end up getting it wrong.
类似的，数据库重构是对数据库方案的简单变更，是在不破坏且不添加东西的情况下改进设计。
Similarly a database refactoring is a simple change to a database schema which improves the design without breaking nor adding anything.
如图4所示，DPF是一种物理数据库设计选项，它在一个多处理环境中使用多个单独的数据库分区。
As Figure 4 shows, DPF is a physical database design option that USES multiple separate database partitions in a multi-processing environment.
为了维护数据库设计的质量，我们甚至可能发现，需要重构现有数据库方案中的某些方面。
We may even find that we need to refactor some aspects of the existing database schema in order to maintain the quality of the database design.
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