The "name" column will be a CHAR (30), set to NOT NULL, and have a unique index on it.
“name”列的类型是CHAR(30)，不允许为空，而且根据此列建立了一个索引。
The primary key and any unique index of the table must be a superset of the associated partitioning key.
表的主键和所有惟一索引都必须是相关分区键的超集。
When a primary key constraint is defined, the federated system automatically creates a unique index specification.
当定义一个主键约束时，联邦系统自动创建一个惟一的索引规范。
Uniqueness in the CCD table must be enforced — either by a primary key or unique index on the source table or CCD table.
ccd表中必须有惟一性约束——可以通过主键或者源表或ccd表上的惟一索引实现。
Also, before setting up replication in DB2, you will want to ensure that every database table has a primary key or unique index.
此外，在DB 2中创建复制之前，您会希望保证每一个数据库表都具有一个主键或惟一索引。
In other words, all columns that are part of the partitioning key must be present in the primary key or unique index definition.
换句话说，作为分区键一部分的所有列都必须出现在主键或惟一索引定义中。
When a unique index is created on a column in Oracle 10g, it ensures that the NOT NULL values entered in that column are unique.
当在Oracle10g中的列上创建UNIQUE索引时，会确保此列中输入的NOT null值是惟一的。
An index specification that defines a unique index also conveys information about the uniqueness of the index columns to the federated system.
定义惟一索引的索引规范还将关于索引列惟一性的信息传递给联邦系统。
From the performance perspective, this is considered a very efficient join operation, because the cost for scanning the inner table is optimal via unique access through a unique index.
从性能的角度来看，这被认为是一个非常有效的联接操作，因为通过贯穿唯一索引的唯一访问扫描内部表的成本是最优的。
However, if the session data conflicts with a new index, (such as duplicate rows conflicting with a unique index), the index is not materialized for that session until the data is corrected.
但是，如果会话数据与某个新索引冲突(比如重复行在唯一的索引上冲突)，则在数据纠正之前不会为该会话物化该索引。
A UNIQUE index creates a constraint such that all values in the index must be distinct.
UNIQUE索引创建一个约束，使得索引中的所有值必须是不同的。
For all engines, a UNIQUE index allows multiple NULL values for columns that can contain NULL.
对于所有引擎，UNIQUE索引允许可以包含NULL的列的多个NULL值。
Pushing responsibility to the database engine could entail the use of creating a UNIQUE index on your table.
向数据库引擎推送责任可能需要在表上创建UNIQUE索引。
Pushing responsibility to the database engine could entail the use of creating a UNIQUE index on your table.
向数据库引擎推送责任可能需要在表上创建UNIQUE索引。
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