Instead of using a numberinteger type field as the surrogate key for your dimension and fact tables model your star schema tables to use a CHARACTER32 as surrogate key field. Take the Staging tables as source tables and take the dimensions as lookups then load the data into fact table.
If you are looking for How To Load Fact And Dimension Tables In Informatica you've reached the ideal location. We ve got 20 images about how to load fact and dimension tables in informatica adding images, photos, pictures, wallpapers, and more. In these web page, we also have variety of images available. Such as png, jpg, animated gifs, pic art, symbol, black and white, translucent, etc.
What Is Dimensional Model In Data Warehouse Data Warehouse Data Structures Data
In current situation to load dimension and fact in same mapping at same time means We can use constraint based loading in that case and after loading all the dimensions table we can load the data into fact table.
How to load fact and dimension tables in informatica. Fact table does not contain a hierarchy whereas the Dimension table contains hierarchies. Answered Sep 27 14 at 1433. How to load Dimensions and facts using informatica.
Also these are dimensions and fact tables. Follow this approach -1. METHOD OF LOADING.
Those containing facts and other containing foreign keys to dimension tables. Create a staging table that looks exactly like your fact table. Inferred members are covered in the DimEmployee dimension ETL later in this Loading a Data Warehouse Topic.
Normally first we load the dimension table then fact table. If you want to know what product is it then in the fact table you need to have a unique number or identifier for the Product_id which will be used to query in the DIM_Product dimension table to get the details of the product name description quantity Supplier. Fact table will have sales quantity data aggregated for product for a monthFact table should be incremental for 24 monthsIt should always contain 24 months of data.
1D_CUSTOMERS SCD 1 2D_PRODUCTS SCD 1 and 3F_SALES_DLY Fact Sales contains daily level data. Loading data into the fact table at least from the SDE extraction side is very similar to the dimension table. Swap the staging table and the fact table this usually involves renaming the tables Understand the Consequences of Your Design.
Populate the staging table with all rows that should be in the fact table. When loading facts you use the dimensions natural key to locate the dimensions primary surrogate key. Preparing your source data to be at the same granularity as your fact table including having the dimension business keys and measures in the source data.
Either we dont load that record into the fact table or we load it but we put 0 as the. While loading the dimension into the DW we should know this fact that in Star Schema these dimension are not related to each other while in. Populate dimension tables with surrogate keys 3.
In general fact table loading involves a few common tasks. Dimension tables are used to describe dimensions. Acquiring the dimension surrogate keys for any related dimension.
They contain dimension keys values and attributes. If a fact table record does not have a corresponding dimension record basically we have 2 choices. This is the starting point.
A Dimension Table is a table in a star schema of a data warehouse. Identifying new records for the fact table and potentially updates. The most important thing about loading fact tables is that first you need to load dimension tables and then according to the specification the fact tables.
When getting the dimension keys from the dimension table we. Generally speaking incremental loading for Fact tables is relatively easier as unlike dimension tables here you do not need to perform any look-up on your target table to find out if the source record already exists in the target or not. You do a Lookup on each dimension individually.
Next once you have all dimensions in place you can write a procedure to load fact tables. Fact table helps to store report labels whereas Dimension table contains detailed data. Fact table is defined by their grain or its most atomic level whereas Dimension table should be wordy descriptive complete and quality assured.
Disable foreign key constraints before the loads to allow data load in the fact tables while dimension tables are being loaded in parallel. Reason is to have the related key value Surrogate Key or the Primary keyForeign Key from the dimension product to the fact sales. The fact table is often located in the center of a star schema surrounded by dimension tables.
It has two types of columns. If you know the way it is handled in informatica then there wont be much difference in writing procedure. You can load the dimension table directly but you cannot load the fact table directly You need to look up the dimension table bcoz fact tables contains foreign keys which are the primary keys in dimension table.
Truncate the staging table. The Inferred Dimension Members screen is about handling placeholder records that were added during the fact table load because a dimension member didnt exist when the fact load was run. Load Stage Tables by doing all data standardization and cleansing 2.
Data warehouses are built using dimensional data models which consist of fact and dimension tables. The SDE mapping takes data from the source table adds the DATASOURCE_NUM_ID and stores it along with the INTEGRATION_ID in the fact staging table. Loading from the fact staging table into the fact table itself is a bit more complex.
When loading the data into the fact table you have to get the relavant dimensional keys surrogate keys from all the dimension tables and then insert the records into the fact table.
