The purpose of Data Warehouse is to simplify the queries that must be run by your reporting tools. Shown below are two queries that fetch the same data—the project type, main assignee, and default category for a specific Dispute project.

To fetch this information from the operational TeamConnect database:

SELECT
    Y_OBJECT_DEFINITION.OBJECT_TITLE
    T_PROJECT.NUMBER_STRING
    T_PROJECT.NAME
    T_CONTACT.NAME
    T_CONTACT.FIRST_NAME
    Y_OBJ_CATEGORY.NAME

FROM
    Y_OBJECT_DEFINITION
    T_PROJECT
    J_PROJ_ASSIGNEE
    Y_USER
    T_CONTACT
    Y_OBJ_CATEGORY

WHERE     
    T_PROJECT.NUMBER_STRING='123'
    AND Y_OBJECT_DEFINITION.OBJECT_TITLE = 'Dispute'
    AND Y_OBJECT_DEFINITION.ENTITY_CODE ='PROJ'
    AND Y_OBJECT_DEFINITION.APPLICATION_ID = T_PROJECT.APPLICATION_ID
    AND Y_OBJ_CATEGORY.PRIMARY_KEY=T_PROJECT.DEFAULT_CATEGORY_ID
    AND T_PROJECT.MAIN_ASSIGNEE_ID=J_PROJ_ASSIGNEE.PRIMARY_KEY
    AND J_PROJ_ASSIGNEE.USER_ID=Y_USER.PRIMARY_KEY
    AND Y_USER.CONTACT_ID=T_CONTACT.PRIMARY_KEY

To fetch this information from Data Warehouse:

SELECT
    WH_PROJECT_DISP.OBJECT_TITLE
    WH_PROJECT_DISP.PROJECT_NUMBER
    WH_PROJECT_DISP.PROJECT_NAME
    WH_PROJECT_DISP.MAIN_ASSIGNEE_NAME
    WH_PROJECT_DISP.MAIN_ASSIGNEE_FIRST_NAME
    WH_PROJECT_DISP.DEFAULT_CATEGORY
FROM
    WH_PROJECT_DISP
    WHERE WH_PROJECT_DISP.PROJECT_NUMBER ='123'

As you can see, Data Warehouse makes querying simpler and more intuitive.