Data Warehouse Surrogate Key Generation
- Nov 17, 2017 Apache Hive RowID Generation. This is quite useful when you need such columns as surrogate keys in data warehouse, as the primary key for data or use as system nature keys.
- Jul 20, 2019 Data warehouse surrogate keys are sequentially generated meaningless numbers associated with each and every record in the data warehouse. These surrogate keys are used to join dimension and fact tables. Usually, database sequences are used to generate surrogate key so it is always unique number; Surrogate keys cannot be NULLs. Surrogate key are never populated with.
- Learn when to use a natural key and when to use a surrogate key in your database or data model, and how to do so with simple SQL. (and How) to Use Surrogate Keys.
Vast is an Ocean,So is vast the World of Knowledge. With my diving suit packed, loaded with imaginative visions, and lots of curiosity, started diving deep into the world of BODS.Lots of work is going on. Got attracted towards the “Key_Generation” transform and was fascinated at its features.Now it was time for me to fuse and adapt myself into its world.
THE KEY_GENERATION TRANSFORM:-
This transform is categorized under the “Data Integrator Transforms”. This generates new keys for source data, starting from a value based on existing keys in the table we specify.
Jun 24, 2012 A surrogate key is an auto generated value, usually integer, in the dimension table. It is made the primary key of the table and is used to join a dimension to a fact table. Among other benefits, surrogate keys allow you to maintain history in a dimension table. Despite of the their popularity, SSIS doesn't have.
If needed to generate Artificial keys in a table, the Key_Generation transform looks up the maximum existing key value from a table and uses it as the starting value to generate new keys.
The transform expects the generated key column to be part of the input schema.
Data Warehouse Surrogate Key Generation Download
STEPS TO USE KEY GENERATION TRANSFORM:-
Scenario:- Here the target data source for which the keys is needed to be added, have certain newly added rows without a Customer_ID. This could be easily understood in the following snap:-
Our aim here is to automatically generate the keys(Customer_ID) in this case , for the newly inserted records which have no Customer_Id. Accordingly we have taken the following as our input (the modified data without Customer_ID)
INPUT DATA (to be staged in the db):-
TARGET TABLE(which contains the data initially contained in the source table before the entry of new records in the database):-
THE GENERATED DATA FLOW:- Watch dogs serial key generator password.
CONTENT OF SOURCE DATA:- (containing the modified entry alone)
CONTENT OF QUERY_TRANSFORM:-
CONTENT OF THE KEY_GENERATION TRANSFORM:-
https://greatgenius.weebly.com/blog/is-it-better-to-boot-camp-a-mac. THE CONTENTS OF THE TARGET TABLE PRIOR JOB EXECUTION:-
The JOB_EXECUTION:-
Data Warehouse Surrogate Key Generation 2017
THE OUTPUT AFTER THE JOB EXECUTION:-
We can now see from the output how Keys have been generated automatically to those records which did not have the Customer_ID initially.
I explored this little process of the Key_Generation transform, and it seems a savior at times when huge amount of data have the missing entries(wrt to the keys or any sequential column fields).
Now its time to go back to the surface of waters…….