从联邦系统上创建远程表。
别名-别名是源数据库中的远程表的本地别名。
Nickname - the nickname is a local alias for the remote table in the source database.
没有外部表、远程表、视图或派生表。
No table is an external table, remote table, view, or derived table.
远程表中每个列中不同值的个数、最大值和最小值
The number of distinct values, and the maximum and minimum values of each column of a remote table
在内部,会创建远程表上的一个影子昵称。
Internally, a shadow nickname is created on the remote table.
远程表被删除。
因此,远程表的定义允许列可以为空这一点非常重要。
Therefore, it is very important for the remote table definition to include column nullability.
无效表——远程表、视图或数据集被删除。
Invalid table - The remote table, view, or data set has been dropped.
在数据源上的远程表上定义索引有时候可以提高查询性能。
Defining indexes on the remote table on the data store might sometimes improve query performance.
在应用程序中,别名可以从远程表、视图或数据集中取回数据。
In an application, a nickname brings back data from a remote table, view, or date set. However, the following conditions will cause such an application to fail.
可以定义远程视图的昵称,就像定义远程表的昵称一样。
A nickname can be defined over a remote view just as it can be defined over a remote table.
远程表和索引的一些物理属性(例如块的数量、索引级别的数量)
Some physical attributes of remote tables and indexes (e.g. number of blocks, number of index levels)
首先,定义一个游标,它使用上面创建的别名读取远程表中的所有行。
First a cursor is defined that reads all rows in the remote table using the nickname created above.
请注意,这些时间只是提供来演示定义在远程表上的MQT所能带来的性能改善。
Please note that these times are provided simply to demonstrate the improvement attainable with MQTs defined over remote tables.
新获取的昵称统计信息中,最重要的是存储在远程表的每个列中的最小值和最大值1 。
The most significant of the newly-retrieved nickname statistics are the minimum and maximum values stored in each column of a remote table 1.
如果远程表在数据上有检查约束,那么可以使用信息检查约束将这些约束传递到联邦服务器。
If the remote tables have restrictions on the data such as check constraints, you can convey these restrictions to the federated server using informational check constraints.
更好的解决办法是定义每个远程表的昵称,必要的时候在联邦服务器上定义这些昵称上的视图。
A better solution is to define a nickname over each remote table, and to define views over these nicknames on the federated server if necessary.
指定了别名,就可以在目标数据库中用sql语句查询远程表,就像查询任何本地表一样。
Specifying the nickname, the remote table can be queried in SQL statements on the target database like any other local table.
客户机可以访问其他数据库中的所有远程表,就像它们是本地DB 2UD b表一样。
All remote tables from other databases are accessible for the client as they would be local DB2 UDB tables.
给items和suppliers的定远程表定义,便可以用以下语句声明相应昵称上的检查约束。
Given the remote table definitions for items and suppliers, you can declare check constraints on the corresponding nicknames with the following commands.
由于联邦系统包含DB 2数据库,因此您还可以存储本地数据库,也可合并来自本地表和远程表的信息。
Because a federated system includes a DB2 database, you can also store local data, as well as combine information from local and remote tables.
由于联邦系统包括一个DB 2数据库,因此还可以在其中存储本地数据以及来自本地和远程表的相关信息。
Because the federated system includes a DB2 database, you can also store local data in it, as well as correlate information from both local and remote tables.
在例子数据模型中,列item_id和suppl_id是远程表items和supplier中的主键。
In the example data model, columns item_id and suppl_id are primary keys in the remote tables, items and supplier.
单击add,然后填充远程模式(public)和远程表名(DELIM1),完成之后单击ok。
Click on Add, and fill in the remote schema (public) and remote table name (DELIM1), then click on OK when finished.
对于涉及到MQT 的执行计划,并且该 MQT 是涉及远程表访问的计划上的 MQT,查询优化器给予它优先权。
The query optimizer will give priority to an execution plan involving an MQT over a plan that involves access to remote tables.
创建“现有表”时,首先会创建一个代理表,然后检索和存储远程表中的元数据,并将该元数据放入到这个代理表中。
Creating an "existing table" creates a proxy table, then retrieves and stores metadata from a remote table and places the metadata into the proxy table.
如果关系数据驻留在远程DB 2或OEM数据库中,那么我们将简单地为我们数据库中的这个远程表创建一个别名。
If the relational data resided in a remote DB2 or OEM database, we would simply create a nickname for this remote table in our database.
当中间那条查询执行完毕并且已经将整个结果集提交给联邦服务器时,才开始执行对远程表 Asia.Sales 的查询。
The query on the remote Asia.Sales table will begin when the one on the middle leg is complete and has delivered its entire result set to the federated server.
如果为一个昵称收集了统计信息,那么在数据源上对相应远程表的远程统计信息进行更新时,这些统计信息不会自动更新。
Once the statistics are gathered for a nickname, they are not automatically modified when the remote statistics are updated on the data source for the corresponding remote table.
该语句在被称作CREDIT_SERVER的远程数据源上创建一个远程表,同时创建一个引用这个新的远程表的昵称。
This statement creates both a remote table on the data source, referred to by the server name CREDIT_SERVER, as well as a nickname referring to this new remote table.
应用推荐