Obiee 简明教程

OBIEE – Multiple Logical Table Sources

当您从当前在 BMM 层中未使用的物理表中拖放一个列时,包含该列的物理表将被添加为新的逻辑表源 (LTS)。

When you drag and drop a column from a physical table that is not currently being used in your logical table in BMM layer, the physical table containing such column gets added as a new Logical Table Source (LTS).

当您在 BMM 层中使用多个表作为源表时,称为多个逻辑表源。当事实表使用不同的物理表作为源时,可以具有多个逻辑表源。

When in BMM layer, you use more than one table as source table, it is called multiple logical table sources. You can have a Fact table as multiple logical table sources when it uses different physical tables as source.

Example

使用 Gemini 将雪花模式的模式在 BMM 层转换为星型模式需要多个 LTS。

Multiple LTS are used to convert Snowflakes schema to Star schemas in BMM layer.

让我们假设你在物理层有两个维度 Dim_EmpDim_Dept ,还有一个事实表 FCT_Attendance

Let us say you have two dimensions − Dim_Emp and Dim_Dept and one fact table FCT_Attendance in the Physical layer.

此处你的 Dim_Emp 被标准化为 Dim_Dept 以便实现雪花模式。所以在你的物理图表中,它类似于这样 −

Here your Dim_Emp is normalized to Dim_Dept to implement Snowflakes schema. So in your Physical diagram, it would be like this −

Dim_Dept<------Dim_Emp <-------FCT_Attendance

当我们将这些表移至 BMM 层时,我们将会使用 2 个逻辑源(对应于 Dim_Emp 和 Dim_Dept)创建一个单一维度表 Dim_Employee。在你的 BMM 图表中,

When we move these table to the BMM layer, we will create a single dimension table Dim_Employee with 2 logical sources corresponding to Dim_Emp and Dim_Dept. In your BMM diagram −

Dim_Employee <-----------FCT_Attendance

这是可以使用 BMM 层中的多个 LTS 概念的一种方法。

This is one approach where you can use concept of multiple LTS in BMM layer.

Specifying Content

当使用多个物理表作为来源时,你可以在 BMM 图表中展开表来源。它显示 BMM 层拾取数据的所有多个 LTS。

When you use multiple physical tables as sources, you expand table sources in BMM diagram. It shows all multiple LTS from where it is picking up the data in BMM layer.

要查看 BMM 层中的表映射,请展开 BMM 层中逻辑表下的来源。它将打开逻辑表来源映射对话框。你可以检查提供数据的所有表以在逻辑表中提供数据。

To see table mapping in BMM layer, expand the sources under logical table in BMM layer. It will open Logical table source mapping dialogue box. You can check all tables which are mapped to provide data in logical table.

specifying content