TOP 25 SAS DI Interview Questions

TOP 25 SAS DI Interview Questions

Enlosing 25 SAS DI questions which candidates frequently encountered in their interviews.

Q1. What is data dimension?

Ans. It is the definition of the customer, product and organization data to be held in central location and to be accessed by all the with governance around change. Common set of dimension are required to support all business views of data and self service reporting. Business view has the capability to segment customer, product and organization data across any dimension.

Q2. What is data access?

Ans. It is the access by selected business users to raw(untransformed) data loads.

Q3. What is data governance?

Ans. It is the robust, reliable, repeatable and controlled process both at point of input and through subsequent downstream control checks. This process exists to manage updates of business rules to maintain a level of consistency.

Q4. What is data reconciliation?

Ans. It Is the correction of the data inconsistency If data is loaded incorrectly from source system and if there is inconsistency between source system and loaded data then source system is treated authoritative.

Q5. What do you mean by exception reporting?

Ans. It is the reporting for data load completion to include any data issues.

Q6.What is multi dimensional reporting?

Ans. It allows users to efficiently aggregate and analyze business metrics across core business dimensions.

Q7.  What do you mean by fact table in dw?

Ans. Fact table represents the subject oriented and the focus of analysis. it generally contains elements f analysis such as sales, cost, quantity sold etc. these attributes can be summed up or averaged in order to understand the particular aspects. Fact table can also be sum up as union of the dimension tables that allows the fact measures to be analyzed from different scenarios.

Q8. What do you mean by dimension tables?

Ans. Dimension table are integral companion to a fact table. It contains the textual descriptions of the business. In a well designed dimensional model, dimension tables have many columns or attributes. These attributes describe the row in the dimensional table. Dimension attributes serve as the primary source of query constraints, groupings and report labels.

Q9. What do you mean by data staging area?

Ans. Staging area of the data warehouse is both the storage area and set of process commonly referred as extract transformation load. The data staging area is everything between the operational source systems and the data presentation area.

Q10. What is slowly changing dimension?

Ans. This is the technique for tracking changes to dimensional table values in order to analyze trends. For example, a dimension table named customers might have columns for customer id, home address and income. Each time the address or income changes for a customer, a new row could be created for that customer in the dimensional table and old row could be retained.

Q11.What is snow flake schema?

Ans. Snow flake schema is defined in which a single fact table is connected to multiple dimension tables. The dimension are structured to minimize update anomalies and to address single themes.

Q12. What is star schema?

Ans. Star schema is defined as database in which single fact table is connected to multiple dimension tables. This is represented in a star schema.

Q13. What is the difference between unique key and primary key?

Ans. Unique key is one or more columns that can be used to uniquely identify a row in a table. A table can have one or more unique keys. Unique keys can contain null values. While on the other hand table can have only one primary key. One or more columns in a primary key cannot contain null values.

Q14. What is SAS application server, database server, SAS OLAP server and SAS metadata server?

Ans. SAS application server provides SAS services to a client. On the other hand database server provides relational database service to a client. Oracle, DB2, and Teradata are examples of relational databases.  SAS OLAP server provides access to multidimensional data. SAS metadata server provides metadata management services to one or more client application.

Q15. What is operational data and operational system?

Ans. Operational data is used as source data for a data warehouse. While operational system is one or more programs that provide source data for a data warehouse.

Q16.What is the use of SAS management console?

Ans. This application provides a single user interface for performing SAS administrative tasks.

Q17.  What is transformation in SAS data integration?

Ans. It is a metadata object which determines how to extract data, transform data and load data into data stores. 

Q18. Name some data transformation used in SAS DI.

Ans. Types of the data transformation are append, apply look up standardization, create match code transformation, data transfer, data validation, extract, fact table lookup, key effective data transformation, lookup, SAS rank, SAS sort, SAS splitter, SCD type 2 loader, SQL join, standardize transformation, Surrogate key generator , Transpose transformation, User written code transformation.

Q19. Describe about metadata object.

Ans. It is a set of attributes that describe a table, a server, a user and another resource on a network.

Q20. Name the scheduler for scheduling job and explain the scheduler.

Ans. The scheduler used for scheduling job is control m while CONTROL-m also user to view process flow and dependencies so that they can optimize business processes easily and efficiently, even in a data center that includes multiple platform types (for example, Unix, Microsoft

Windows, and MVS)

Q21. What is change analysis in SAS DI ?

Ans.Change analysis is the process of comparing one set of metadata to another set of metadata and identifying the differences between the two sets of metadata.

Q22. Describe the interaction table in SAS DI.

Ans. Table that describes the relationships between two or more tables. For example, an intersection table could describe the many-to-many relationships between a table of users and a table of groups.

Q23. Explain the difference between alternate key, business key, foreign key , generated key , primary key, retained key and surrogate key .

Ans. Alternate key is term also known as unique key. 

Business key is one or more columns in a dimension table that comprise the primary key in a source table in an operational system.

Foreign key is one or more columns that are associated with a primary key or unique key in another table. A table can have one or more foreign keys. A foreign key is dependent upon its associated primary or unique key. In other words, a foreign key cannot exist without that primary or unique key.

Generated keys is used to implement surrogate keys and retained keys, one or more columns that are used to uniquely identify a row in a table. A table can have only one primary key. One or more columns in a primary key cannot contain null values.

Retained key is a numeric column in a dimension table that is the primary key of that table. 

Surrogate key is a column which contains unique integer values that are generated sequentially when rows are added and updated. In the associated fact table, the surrogate key is included as a foreign key in order to connect to specific dimensions.

Q24. What are the prons and cons of the SAS DI?

Ans. SAS data integration projects have a number of advantages over projects that rely heavily on custom code and multiple tools that are not well integrated.SAS data integration reduces development time by enabling the rapid generation of data warehouses, data marts, and data streams.

SAS DI suffer from performance issues sometime, it generates very complex code which are very hard to decode.

Q25. Describe deployment of SAS Data Integration studio jobs as a SAS stored process.

Ans. Job can be deploy as a SAS stored process in  SAS Data Integration Studio. Code is generated for the stored process and the code is saved to a file in a source repository. Metadata about the stored process is saved to the current metadata server. The stored process can be executed as required by requesting applications.Stored processes can be used for Web reporting, analytics, building Web applications,delivering result packages to clients or the middle tier, and publishing results to channels

or repositories. Stored processes can also access any SAS data source or external file and create new data sets, files, or other data targets supported by the SAS System.

SAS Interview Question (Advance Level)