Country block exemptions by HS code

List of the table of contents of this article:

• 1,Country block exemptions by HS codedata layering
• 2, What does ODS mean?
• 3, numberAccording to the product work, the north (3)-real-time digital warehouse layering

data layering

The "theme-oriented" data operation layer, also known as the ODS layer, is the closest layer to the data source. The data in the data source, through After extraction, washing and transmission, that is to say, after the legendary ETL, it is loaded into this layer. In general, most of the data at this layer is classified according to the classification method of the source business system.

In statistics, stratification refers to dividing a population or a population into multiple levels according to different characteristics. In sample research, in order to improve the reliability and accuracy of the data, it is often necessary to carry out stratified sampling. At this time, it is necessary to calculate the hierarchical sample variance.

Data layeringThe purpose is to improve the efficiency and accuracy of data processing, simplify the data processing process, optimize the data storage space, etc.

[Answer]: B The number of layers in layers has nothing to do with the size of the data volume, so A is wrong. Only relevant signs with layers can be layered, so D is wrong.

The principle of using the hierarchical method: the data fluctuation in the layer should be as small as possible, and the data difference between the layers should be as large as possible.

DW data stratification, from bottom to top are DWD, DWB, DWS DWD: data warehouse detail detail data layer, also known as ODS layer, is the separation layer between the business layer and the data warehouse.

What does ODS mean?

1, operational data store.Operable data storage (ODS) refers to a database that is often used as a temporary area of a data warehouse. Unlike the data warehouse containing static data, the content of ODS is updated through the commercial operation process.

2. ODS is a thematic, integrated, variable and current detailed data collection used to support the needs of enterprises for immediate, operational and integrated information. It is often used as a transition to the data warehouse, and it is also one of the options for data warehouse projects.

3. ods is the abbreviation of Open Document Spreadsheet, which represents a spreadsheet file in OpenDocument format. OpenDocument is an open standard by OASIS(Organization for the Advancement of Structured Information Standards) formulation and development.

4. ods means data table, which is a Microsoft Outlook Express mailbox file, which is generally opened with OpenOffice. The .ods file cannot be opened normally. To open this file, you need to install Ope on your computer. nOffice software, and then click the .ods file directly to view the content of the file.

5. ODS - operational data. ODS is known as Operational Data Store, is a system used to store business data from multiple data sources. Its data is used to support business processes or input into the data warehouse for analysis. It is mainly used for business support.

Data product work refers to north (3)-real-time digital warehouse stratification

According to the actual business, the digital warehouse is divided into ODS, DW, SCD, RPT layers, and the DIM dimension layer will run through all layers. , for the convenience of background query, it will be put into the RPT layer. The ODS layer stores data synchronized from the business source system. The prefix [ODS_Business Abbreviated_] is added to the table name, and the table structure and data structure are consistent with the source system.

Source Data Layer (ODS): There is no change in the data of this layer. It directly follows the data structure and data of the peripheral system, and is not open to the public;For the temporary storage layer, it is the temporary storage area of interface data to prepare for the data processing of the next step.

This layer mainly provides data for data products and data analysis. It is generally stored in ES, MySQL and other systems for online system use. It may also exist in Hive or Druid for data analysis and data mining. For example, the report data we often talk about, or the kind of wide table, is generally placed here.

So it is generally said to be a three-layer model: data operation layer (ODS), data warehouse layer (DW) and data application layer (APP).