sharding

One way to scale out a shared database is database sharding .

横向扩展共享数据库的一种方式是数据库分片。

The sharding engine described above uses the sharding strategy provided by the application .

上面描述的分片引擎使用应用程序提供的分片策略。

Next , I need to verify that my sharding implementation works .

接下来，我需要验证我的切分实现可以工作。

Accordingly , you must implement this interface and code the sharding logic .

因此，您必须实现该接口并对切分逻辑进行编码。

Clearly , you 'll need to fully consider a sharding strategy before you set up your database .

很明显，在建立数据库前必须全面考虑切分策略。

A simple technique to scale out a shared database is through database sharding based on tenant ID.

一种简单的方法是基于承租者ID、通过数据库分片横向扩展共享数据库。

Jan notes that the technique can also be used to implement other data distribution strategies , such as sharding .

Jan提醒说这个技巧还可以用来实现其他的数据分布策略，例如分片（Sharding）。

Basic concepts in horizontal partitioning / sharding

水平分区/分片的基本概念

In the right situation , sharding could be key to unlocking scale and speed in a traditional RDBMS .

如果能够正确实现，切分可以用于解决传统RDBMS规模和速度问题。

Key changes include the addition of journaling , sharding performance boosts , and shell tab completion .

关键的变更包括新增Journaling日志、提升分片性能以及Shell的Tab​补全。

Slice has extended OpenJPA implementation to support data partitions or sharding in a seamless manner .

Slice扩展了OpenJPA实现，使其能够无缝地支持数据分区。

Database sharding refers to the horizontal partitioning of a database with each individual partition called a shard .

数据库分片是指对数据库进行水平分区，其中每个分区称为一个碎片。

Microsoft will release SQL Azure Federations which will support sharding at the database level in2011 .

微软将在2011年发布SQLAzureFederations，它将支持数据库级别的分片。

Sharding leverages multiple databases , all of which function autonomously , without awareness of their peers .

切分利用多个数据库，其中所有数据库都独立起作用，不干涉其他切分。

Interfaces for implementing application-specific sharding strategy .

实现特定于应用程序的分片策略的界面。

WebSphere CloudBurst also includes an image repository , built into the appliance , which leverages encryption and sharding technologies .

WebSphereCloudBurst还包含一个内置到设备中的映像库，该库利用了加密和碎片技术。

And because sharding is done at the application layer , you can do it for databases that don 't support regular partitioning .

而且因为切分是在应用程序层面进行的，您可以对不支持常规分区的数据库进行切分处理。

Unlike other sharding solutions , Slice does not require adding any extra column to the existing schema to enable partitioning .

与其他的分区解决方案不同，Slice并不需要向现有模式中添加任何额外的列以支持分区。

Sequel supports advanced database features such as prepared statements , bound variables , master / slave configurations , and database sharding .

Sequel支持高级的数据库特性，比如语句准备，参数绑定，主/从配置，以及数据库分片。

Horizontal partitioning can be done both within a single server and across multiple servers , the latter often being referred to as sharding .

水平分区既可以在单个服务器中完成，也可以跨多个服务器完成，后者经常指的就是分片（sharding）。

This month , I 'll use this familiar example to introduce a practical sharding strategy , then implement it in Hibernate Shards .

本月，我将继续使用这个熟悉的示例介绍一种实用的切分技术，然后在HibernateShards中对其进行实现。

Sharding : A test drive with easyb

切分：使用easyb的测试驱动

It would be far easier to build a bigger database server , and push off the need to rebuild your application to support the sharding of data .

使用更强大的数据库服务器要容易得多，而且不需要通过重新构建应用程序来支持分散的数据。

Sharding , an offshoot of database partitioning , isn 't a native database technique & it happens at the level of the application .

切分是数据库分区的一个分支，但是它不是本地数据库技术&切分发生在应用程序级别。

Both primary keys and cross-shard queries play a major role when sharding , mainly by defining what you can 't do .

进行切分时主键和跨切分查询都扮演重要角色，主要通过定义您不可以做什么实现。

Sharding 's costs ( or cons ) include the burden of coding application-specific logic for how data will be stored and retrieved .

切分的成本（或者说缺点）包括对如何存储和检索数据的特定应用程序逻辑进行编码的成本。

As I mentioned earlier , sharding forces you to be keenly aware of primary keys , as you 'll manage them yourself .

如我之前提到的那样，切分迫使您重视主键，因为您将需要亲自管理这些主键。

That is , rather than splitting up a table into smaller chunks , sharding splits up an entire database into smaller chunks .

也就是说，切分不是将数据表分割成小块，而是将整个数据库分割成小块。

Standard JPA has no effective means of dealing with sharding or portioning as the specification implicitly assumes a single database as the repository .

标准JPA没有处理分区或分配的有效方式，因为规范已经隐式地假定单个数据库作为存储库。

In order to facilitate this , MongoDB relies on the concepts of sharding and replication , which you will learn about in this section .

为了发挥这些优势，MongoDB引入了分片和复制的概念，您将在本节中学习。