Obiee 简明教程

OBIEE – Aggregates

聚合用于在运行报告时实现查询性能优化。这消除了查询在运行计算所花费的时间,并快速提供了结果。聚合表与普通表相比具有较少数量的行。

Aggregations are used to implement query performance optimization while running the reports. This eliminates the time taken by query to run the calculations and delivers the results at fast speed. Aggregate tables has less number of rows as compared to a normal table.

How Aggregation Works in OBIEE?

当您在 OBIEE 中执行查询时,BI 服务器会寻找具有回答查询的信息的资源。在所有可用源中,服务器选择最聚合的源来回答该查询。

When you execute a query in OBIEE, BI server looks for the resources which has information to answer the query. Out of all available sources, the server selects the most aggregated source to answer that query.

Adding Aggregation in a Repository

在管理员工具中以脱机模式打开存储库。转到文件 → 打开 → 脱机。

Open the Repository in an offline mode in the Administrator tool. Go to File → Open → Offline.

导入元数据并创建 BMM 层中的逻辑表源。展开表名称并单击源表名称以打开逻辑表源对话框。

Import the metadata and create logical table source in BMM layer. Expand the table name and click on source table name to open logical table source dialog box.

转到“列映射”选项卡以查看物理表中映射的列。转到“内容”选项卡 → 通过选择逻辑级别对聚合内容组进行分组。

Go to column mapping tab to see map columns in Physical table. Go to content tab → Aggregate content group by selecting the logical level.

adding aggregation in repository

您可以根据事实表中的列选择不同的逻辑级别,例如产品总计,总收入以及根据维度层次结构的时间季度/年份。

You can select different logical levels as per the columns in fact tables like Product Total, Total Revenue, and Quarter/Year for Time as per dimension hierarchies.

select different logical levels

单击确定以关闭对话框 → 保存存储库。

Click OK to close dialog box → save the repository.

当您在逻辑事实表中定义聚合时,会按照维度层次结构进行定义。

When you define Aggregate in logical fact tables they are defined as per dimension hierarchies.