fact tables and dimension tables in data warehousing

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 o

Introduction Fact table The foreign key that stores the measurement value and dimension table. Dimension Table Angle and category. Time, region, and status. Old Method Select * from order oinner join district d on o. discode = d. discodeinner join address a on o. addressid =. addressidwhere o. createdate> '2014-2-5 'and o. createdate It is difficult to add co

A typical example is to compare the logical business to a cube, the product dimension, the time dimension, and the location dimension as different axes, and the intersection of the axes is a detailed fact. This means that the fact table is an intersection of multiple

Transaction fact tables, periodic snapshot fact tables, and cumulative snapshot fact tables, fact snapshotsIn the field of data warehousing

The original: "Bi thing-the art of data" understanding Dimension Data Warehouse-fact table, dimension table, aggregation tableFact tableIn a multidimensional data warehouse, a table that holds a detailed value or

tables will have different measures. A sales data warehouse may contain these two measure columns: Sales and sales. A field information Data Warehouse may contain 3 measure columns: Total, number of minutes, and number of defects. When you create a report, you can think of a measure as an extra dimension. That is, you

Some people often ask a question: do fact tables and dimension tables must be in a database? Why is there such a problem? As we mentioned, if the data warehouse is large enough, it may be split into so-called data mart. Generally,

In the past, the dimension tables, fact tables, data analysis, BI and other concepts have some ambiguity. These days of study finally let these have some clues:A dimension represents the amount of

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 o

I. DataCubeIt is defined by dimensions and facts. A dimension is a perspective or entity that an organization wants to save records. One or a group of attributes in the corresponding dimension mode. This mode should be a fact table (central table ). Each dimension has a table associated with it, which is called a

SQL Application and Development: (5) connecting multiple data tables and multiple SQL tables Different tables in the database store different data. Users often need to use the data in multiple

with UTF8 character setCREATE DATABASE IF not EXISTS ' db ' DEFAULT CHARACTER SET UTF8;--9. Deleting a databaseDROP DATABASE IF EXISTS ren2;DROP DATABASE IF EXISTS ren1;--10. View the DatabaseSHOW DATABASES;--11. Common Information functionsSELECT VERSION (); --Current database server version informationSELECT DATABASE (); --Query the current librarySELECT Current_User (); --View the current userSELECT USER (); --View the current userSELECT curdate (); --View the current userSELECT current_date

MYSQL Tutorial: check the data table and repair the data table MySQL server uses the permission table to control user access to the database. The permission table is stored in the mysql database and initialized by the mysql_install_db script. These permission tables are user, db, table_priv, columns_priv, and host respectively. The following describes the structu

MYSQL checks the data table and repairs the data table. when the database is running, data corruption may occur due to human factors or some force majeure factors. Therefore, to protect data security and minimize downtime, we need to develop a detailed backup/recovery plan and regularly test the effectiveness of the pl