表的主键和所有惟一索引都必须是相关分区键的超集。
The primary key and any unique index of the table must be a superset of the associated partitioning key.
索引idx6还是与查询6中的谓词相匹配的惟一索引。
Index idx6 is also the only index that matches the predicate in query 6.
然而，DB 2复制要求使用一个主键或惟一索引来区分一个表中的记录。
However, DB2 replication requires a key or index to uniquely identify rows in a table.
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。
In other words, all columns that are part of the partitioning key must be present in the primary key or unique index definition.
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。
An index specification that defines a unique index also conveys information about the uniqueness of the index columns to the federated system.
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。
Uniqueness in the CCD table must be enforced — either by a primary key or unique index on the source table or CCD table.
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。
Also, before setting up replication in DB2, you will want to ensure that every database table has a primary key or unique index.
如果在一个类中的多个属性上定义惟一性，那么应该创建一个包含所有这些属性的索引。
If you define uniqueness on multiple attributes within a class, create one index that includes all the attributes.
该参数可以不要，因为默认设置就是只考虑索引，这也是我们在这个案例研究中惟一感兴趣的。
This parameter is not required as the default is indexes only, which is all we are interested in this case study.
索引的层次和惟一性也会影响数据的访问速度。
The level and uniqueness of an index will also affect the speed of accessing data.
惟一的例外是，具有较少写活动和不可预测的查询工作负载的应用程序，这种应用程序难于定义更明确的索引。
The only exception could be applications with low write activity and unpredictable query workload such that more specific indexes are hard to define.
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。
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.
索引的惟一性是指一个索引拥有多少个重复键。
The uniqueness of index refers to how many duplicate keys an index has.
计算这个元素集的结束索引值的惟一方法是，求出前面的所有片和当前片中出现的值的总数。
The ending index value of this set of elements can be calculated only by adding up the total number of values that occurred in all preceding slices plus the current slice.
计算这个元素集的启始索引值的惟一方法是，求出前面的所有片中出现的值的总数。
The starting index value of this set of elements can be calculated only by adding up the total number of values that occurred in all of the preceding slices.
用以读取叶子页面的成本取决于索引的大小、查询的筛选器以及索引的惟一性。
The costs used to find a leaf page depends on the size of the index, the filer of the query, and the uniqueness of the index.
注意，通常情况下，CSCDISIS属性并不是惟一有数据库索引的属性。
Note that this is usually not the only attribute with a database index.
搜索、视图、惟一性和索引。
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 number of unique entries in an index, which can be used to estimate the number of rows that an equality filter returns.
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。
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.
这是使用WindowsIndexingService访问索引内容时的惟一需求。
That's the only requirement to access the indexed content when working with Windows Indexing Service.
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。
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.
为了展示这一点，将它与计划中第5号索引扫描上使用的谓词相比较，它针对子表中惟一的索引列。
To illustrate this, compare it to the predicate that is applied to the index scan numbered 5 in the plan, which is on the one and only column of the index on the child table.
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)。
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.)
索引的创建，惟一或不惟一，都有助于以不同的方式从MQT读取数据，导致更好的性能。
Creation of indexes, unique or otherwise, helps read the data from MQTs in an efficient manner, resulting in better performance.
现在，我们如何查明索引是不是惟一的呢？
理想情况是，索引中的每个键值都是惟一的。
如果MQT具有一个键，那么应该创建惟一的索引以反映这一事实。
If the MQT happens to have a key, unique indexes should be created to reflect the fact.
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。
When a primary key constraint is defined, the federated system automatically creates a unique index specification.
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。
The index is created by querying the database for the list of unique categories and brands for all the products in the database.
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