qlikview dimension

When we create dimensions in SSAs, it is sometimes possible that one dimension needs to use multiple table fields as dimension attributes, so there is bound to be an association between the multiple tables, but remember that the correlation between the dimension tables and only one cannot have multiple, let's look at an example.Now we have created a

The support vector machine method is based on the VC dimension Theory of statistical learning theory and the minimum structure risk principle.Confidence risk: The classifier classifies the unknown sample and obtains the error. Experiential risk: A well-trained classifier that re-classifies the training samples. That is, sample error structure risk: Confidence risk + empirical risk structure risk minimization is a strategy proposed to prevent overfitti

Foundataions of machine learning: Rademacher complexity and VC-dimension (2) (1) growth Function) Before introducing the growth function, let's introduce an example which will help you understand the growth function. When the input space is $ \ mathbb {r} $, assume that the space is a threshold function, that is, when the input vertex $ x> V $, The point is marked as positive. For example, Figure 1 shows the six assumptions. Figure 1 threshold functi

Fact tableEach data warehouse contains one or more fact data tables. Fact data tables may contain business sales data, such as data generated by cash registration firms. Fact data tables usually contain a large number of rows. Fact data tables are mainly characterized by digital data (FACTS) that can be summarized to provide relevant units as historical data, each fact table contains an index composed of multiple parts. This index contains the primary key of the foreign key's correlated latitude

Tags: http data problems ad EF Time Database. Net TT Bi Data Warehouse product database storage A typical example is to compare a logical business to a cube. The product dimension, time dimension, and location dimension are different coordinate axes, and the intersection of coordinate axes is a specific fact. That is to say, a fact table is an intersection of m

Here's a brief talk of SCD.Put two useful link addresses before you speak. The author's two papers explain what SCD is and how it is appliedHttp://www.cnblogs.com/biwork/p/3363749.htmlHttp://www.cnblogs.com/biwork/p/3371338.htmlSlow changing dimension translation comes down to the slowly changing dimension. It is applied to the loading of dimension table data in

We often encounter this problem in the design of the Data Warehouse: If the dimension has only one attribute in the dimension design, is the choice to create a single dimension for this attribute, or will the attribute of that dimension be placed directly in the fact table as part of the fact table?Suppose there is a

The primary key in a dimension table usually has two choices: the Natural key (Natural key), which is already present in the business system, usually a character-type marker with a certain business meaning, which uniquely flags each of the dimension tablesRecording. Like whatOrganization's code, abbreviations, time tags, and so on. The other is the surrogate key (surrogate key), which is usuallyA numeric va

Abstract Yes With the development of computers and the increasing number of data islands in information systems, how to use the data is a problem facing every enterprise.ETLYesexponential Data Extraction(Extract), Data Conversion(Transform)And Data Loading(Loading)And plays a key role in the application of data warehouse.ETLUse these data islands to form a data warehouse,It is an extremely important part in building a data warehouse. Slow change dimen