然而在缺乏数据分布信息的情况下,优化器将基于表索引计算不同类型筛选器的选择性。
However, in the absence of data distribution information, the optimizer will calculate selectivity for filters of different types based on table indexes.
但是,如果没有数据分布,则数据库服务器根据表索引计算不同类型的过滤器的选择率。
However, in the absence of data distributions, the database server calculates selectivity for filters of different types based on table indexes.
正如下面解释的一样,在使用这个特性之前,要确保您已经配置了要搜索的列,并且已经正确地创建了表索引。
As explained below, be sure you have configured the search columns and properly indexed your tables before using this feature.
默认情况下,不同的IBMtsom表是在默认表空间创建的,所以您应该使用另一个表空间来存储事件数据和事件表索引。
By default all the different IBM TSOM tables are created in the default table space, so you should use a separate table space for event data and event table indexes.
表索引。标准表或者排序表的最后被定位的行(表循环中当前所在行)。如果访问哈希表,则设置为0。
Table index. Last addressed line of a standard table or sorted table. Is set to 0 if hashed table is accessed.
有了新建的索引,所有表都可以用索引扫描访问。
With the newly created indexes, all tables are accessed with index scans.
对于本文的查询样例,图12显示了索引报告,它描述了引用表的现有索引。
For the sample query in this article, Figure 12 shows the index report, which describes the existing indexes of the referenced tables.
尽可能避免表上有任何索引,尤其是不要有群集索引。
Avoid having any indexes on the table, if possible, but particularly not a clustering index.
DB 2索引顾问(index adviser)辅助设计表上的索引。
DB2 index adviser provides assistance in the designing of indexes on tables. It is useful in the following situations.
索引能够避免全表扫描,从而能够提高查询性能。
Indexes improve query performance by avoiding a full table scan.
访问计划定义按什么顺序访问表,使用哪些索引,以及用何种连接(join)方法来关联数据。
An access plan defines the order for accessing tables, which indexes are used, and by what kind of join methods data is correlated.
目前的CTP 1仅支持表、索引和约束。
应用程序准备(编译)好一条语句之后,可以修改语句对象——表、索引、统计信息。
After a statement has been prepared (compiled) by the application, the statement objects — tables, indexes, statistics — can be altered.
现在来看看DB 2数据库对象(比如模式、表、索引和存储过程)的实现以及这些对象的应用程序接口。
Now turn your attention to the implementation of the DB2 database objects (such as, schema, tables, indexes, and stored procedures) and the application interface to these objects.
例如,DB 2Fundamentals考试测试考生的安全知识,表、索引和视图的创建和使用,SQL使用,以及隔离级别和锁定。
For example, the DB2 Fundamentals exam tests a candidate's knowledge of security; creating and working with tables, indexes, and views; using SQL; and isolation levels and locking.
每个数据库对象有0到多个(0. .n)模式,每个模式可以有0到多个(0 . . n)表、索引、用户定义类型和例程等。
A database object can have zero to many (0.. n) schemas, and a schema can have zero to many (0.. n) tables, indexes, user-defined types, routines, and so on.
自动表和索引重组。
创建表和索引。
恢复所有不同的类型,然后恢复所有表及其索引。
Restore all distinct types followed by all tables with their indexes.
缩小表或索引空间的规模。
该脚本创建一个包含关于表和索引使用的细节的报告。
The script creates a report that provides details about table and index usage.
在单个dbspace中存储多个表或索引片段。
Storing multiple table or index fragments in a single dbspace.
应当有多个磁盘用于DB 2日志、表和索引。
There should be multiple disks for the DB2 logs, for tables, and for indexes.
tcbstats all显示所有表和索引度量指标
表和索引可以驻留在不同的dbspace中。
关于表空间和索引节点组或分区的信息。
Information about the table space and index node groups or partitions.
书的最后一部分包括附录、术语表和索引。
The last section of the book includes the appendices, the glossary, and an index.
创建表、视图、索引、触发器等的ddl语句。
Generate DDL statements for tables, view, indexes, triggers, and more.
此外,DeepCompression则被用于压缩表和索引数据。
In addition, Deep Compression was used to compress both table and index data.
那么,确定将哪些db2表或索引放在SSD上的最佳方式是什么?
So, what's the best way to determine which DB2 tables or indexes to place on SSDs?
应用推荐