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。
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。
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。
You cannot create a unique index on a single column if that column contains NULL in more than one row.
如果一个以上的资料列中的某单一资料行为NULL，您将无法建立该单一资料行的唯一索引。
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。
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。
The new table 'test'. '_online_table_new' does not have a PRIMARY KEY or a unique index which is required for the DELETE trigger.
原表需要一个主键或则唯一索引，因为删除的触发器需要，否则数据不会被复制。
Similarly, you cannot create a unique index on multiple columns if the combination of columns contains NULL in more than one row.
同样地，如果一个以上的资料列中的一组资料行全为NULL的话，您将无法在该组资料行上建立唯一索引。
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。
It then encrypts the index using a searchable encryption scheme and encrypts the unique key with an attribute-based encryption scheme under an appropriate policy.
然后它会使用可搜索的加密模式对索引进行加密，用基于属性的加密模式以恰当的手段对唯一密钥加密。
For indexes that are not unique, the number of index keys is less than the number of records.
对于那些不是唯一的索引，索引键的数量要少于记录的数量。
The table is logically joined to itself, and the more selective non-leading index keys are applied as index bound filters to each unique combination of the leading key values.
首先在逻辑上将表与其自身连接，然后将更具有选择性的非起始索引键作为索引绑定过滤器，应用于起始键值的每个惟一的组合。
However, since XML columns cannot be part of the table partitioning key, any unique XML values index will have to be created as a global index.
然而，由于xml列不属于表分区键的一部分，任何唯一xml值索引必须创建为全局索引。
Many repositories have unique ways of storing native content and metadata. OmniFind, for example, does not actually store the native content for an item in its index.
许多存储库具有存储原始内容和元数据的独特方法，例如，OmniFind并不是真的将项目的原始内容存储在它的索引中。
The reason for this is that the other tables in the DB2 UDB SAMPLE database have no primary key, and hence no index information to associate a unique ECO key with.
原因是DB2UDBSAMPLE数据库中的其他表没有主键，因此没有索引信息可以关联惟一的ECO 键。
Assign each LPAR a unique GUID index within each physical computer to distinguish the different LPARs using InfiniBand.
在每一个物理计算机上给每一个LPAR分配一个唯一的GUID索引，以区分使用InfiniBand的不同LPAR。
A primary index is a unique feature of Teradata's database - it offers the benefit of an index without the traditional overhead associated with an index.
主索引是teradata数据库的惟一特性—在避免索引相关额外开销的情况下提供索引的优势。
Because the partno field is declared unique, repeated upload operations of the same part number merely replace the old index record with a new record.
由于声明了partno字段惟一，因此重复上传同一个部件号将只用新记录替换旧索引记录。
The number of unique entries in an index, which can be used to estimate the number of rows that an equality filter returns.
索引中的惟一项数目，可用于估算等式筛选器所返回的行数。
The id modifier further declares that the id field must be unique. (Solr does not require a unique id field; this is merely a rule established in the default index schema.)
id修饰词进一步说明id字段必须惟一(Solr不要求id字段惟一；这只是在默认索引模式中建立的规则)。
For example, non-unique element names can keep you from properly evaluating code that performs fewer index look-ups.
例如，非唯一元素能够阻止您正确评估执行较少索引查询的代码。
The index is created by querying the database for the list of unique categories and brands for all the products in the database.
索引通过查询数据库中所有产品的惟一种类和品牌的列表而创建。
There are two types of Primary Indexes - unique Primary Index (UPI) and Non-unique Primary Index (NUPI).
有两种主索引—惟一主索引(upi)与非惟一主索引(NUPI)。
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