星形模式的基本特点是由多个维表(Dimension Table)和事实表(Fact Table)组成。维表代表了相关的分析维度，事实表则是这些不同维度上的计算结果。星形模式存储了系统在不同维度上的预处理结果，因此进行多维分析时速度很快，但如果分析范围超出了
23、rms is that repeated entries are removed from a second normal form table and placed in their own "snowflake." Thus the act of removing the context from a fact record and creating dimension tables places the fact table in third normal form.I resist the urge to further snowflake the di...
1。 根据Fact 来动态生成 Dimension Table, Dim 中的字段被特殊定义成 Supplier_id, Suppliers. 如上实例中,此Dim Table 中应该有三笔记录。 Supplier_id Suppliers AAA AAA, BBB, CCC BBB AAA, BBB, CCC CCC AAA, BBB, CCC 因为Suppliers 中所存放值是由Fact Table 遍历生成,所以能与Fact Table 能完全匹...
一般来说,一个事实数据表都要和一个或多个维度表相关联,用户在利用事实数据表创建多维数据集时,可以使用一个或多个维度表。 维度表 维度表可以看作是用户来分析数据的窗口,维度表中包含事 实数据表中事实记录的特性,有些特性提供描述性信息,有些特性指定如何汇总事实数据表数据,以便为分析者提供有用的信息,维度...
A Fact Table is a key table in data warehousing that maintains quantitative data about a business process or event, such as sales transactions, inventory levels, or customer orders. It covers the major indicators and measures that are used to analyze and assess a company’s performance. Fact ...
Characteristics of a Fact Table The following are some of the characteristics of a fact table: Outrigger Dimensions: Outrigger dimensions are dimensions that refer to any other dimension table. Keys: Each fact table has a key that is made up of the primary keys from all of the dimension tabl...
星型模型 星型模型( star schema) 是一种多维数据关系,有一个事实表( Fact table) 和一 组维表(Dimension table) 组成。每个 … www.docin.com|基于194个网页 3. 维度资料表 维度资料表(dimension table) 用来定义事实资料表中的栏位,例如售货员姓名、交易类型或是项目等等。这个过程与 正规化… ...
dimension table to possess primary keys that aren't found in the fact table. Therefore, a product dimension table might be paired with a sales fact table in which some of the products are never sold. This situation is perfectly consistent with referential integrity and proper dimensional ...
事实表(Fact Table)是指存储有事实记录的表,如系统日志、销售记录、传感器数值等;事实表的记录是动态增长的,所以它的体积通常远大于维度表。 维度表(Dimension Table)或维表,也成为查找表(Lookup Table),是与事实表相对应的一种表;它保存了维度的属性值,可以跟事实表做关联;相当于将事实表上经常重复的属性抽取、...
dimension table to possess primary keys that aren’t found in the fact table. Therefore, a product dimension table might be paired with a sales fact table in which some of the products are never sold. This situation is perfectly consistent with referential integrity and proper dimensional ...