An attribute is a specification that defines a property of an object, element, or file. It may also refer to or set the specific value for a given instance of such.
What is surrogate key?
A surrogate key is the SQL generated key which acts like an alternate primary key for the table in database, Data warehouses commonly use a surrogate key to uniquely identify an entity. A surrogate is not generated by the user but by the system. A primary difference between a primary key and surrogate key in few databases is that primarykey uniquely identifies a record while a Surrogatekey uniquely identifies an entity.
Ex: An employee may be recruited before the year 2000 while another employee with the same name may be recruited after the year 2000. Here, the primary key will uniquely identify the record while the surrogate key will be generated by the system (say a serial number) since the SK is NOT derived from the data.
How many types of relations are there between dimension and measure group?
They are six relation between the dimension and measure group, they are
No Relationship
Regular
Refernce
Many to Many
Data Mining
Fact
How you move the cube from one server to another?
There are many ways to do the same. Let me explain four here and cleverly you can say “I worked on 4 SSAS projects till date and implemented different types in all the four.”
Backup and restore – This is the simplest way. Take the Backup from development server and copy the backup to FTP folder of clients. After doing this drop a mail to Client’s Admin and he will take care of RESTORE part.
Directly PROCESS the cube in PRODUCTION environment. For this you need access to Production which will not be given by clients unless the clients are *********. One of the client I worked for given FULL access to me ..
Under Srart –> All Programs –> Sql Server –> Analysis Services you can see deployment wizard. This is one way of moving the cube. This method has some steps to follow. First deploy your cube and FOUR files will be created in BIN folder of PROJECT folder. Copy those FOUR files and paste in Production server in any directory. Then OPEN this DEPLOYMENT Wizard in production and when it ask for Database file then point to the location where you copied the files. After that NEXT,NEXT,NEXT … OK .. Cube will be deployed and processed.
This way is most beautiful one. Synchronization, In this we will first deploy and process the cube in STAGING ENVIRONMENT and then we will go to production server. Connect to Analysis services in SSMS and select Synchronize by right clicking on Databases folder in SSMS of analysis services. Then select source as STAGING SERVER and then click on OK. The changes in the cube present in the Staging server will be copied to the production server.
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| CDW Most Frequently Asked Latest SSAS Interview Questions Answers |
What is the toughest challenge you face in your Project?
There are couple of this where we face difficulty.
While working on RELATIONSHIPS between Measure Groups and Dimensions.
Working on Complex calculations
Performance tuning
How you created Partitions of the cube in your Last Project?
Partitions can be created on different data. Few people do it on PRODUCT NAME wise and many prefer to do it on DATE data wise. you go with DATE wise.
In dates, we can create MONTH wise,WEEK wise,QUARTER wise and some times YEAR wise. This all depends on how much data you are coming per WEEK or MONTH or QUARTER … If you are getting 50 lakhs records per month then tell you do MONTH wise.
How many dimensions in your last cube?
47 to 50.
How many measure groups in your last cube?
Total 10 and in that 4 are Fact tables and remaining 6 are Fact less fact tables.
What is the Schema of your last cube?
Snowflake
Why not STAR Schema ?
My data base design doesn’t support STAR Schema.
What are the different relationships that you are used in your cube?
Regular
Referenced
Many to Many
Fact
No Relationship
Have you created the KPI’s , If then Explain?
Don’t add much to this as the questions in this will be tricky. Just tell that you worked on couple of KPI and you have basic knowledge on this. (Don’t worry, this is not MANDATORY)
How you define Aggregations in your Project?
We defined the aggregations for MOST FREQUENTLY USED data in SSRS reports.
Size of SSAS team in your last Project?
Just 2 guys as we guys are really in demand and lot of scarcity:)
How many Resources worked on same Cube in your Project?
Only 2 and one in morning shift and another in Evening shift.
What are Aggregations and its use?
Aggregations provide performance improvements by allowing Microsoft SQL Server Analysis Services (SSAS) to retrieve pre-calculated totals directly from cube storage instead of having to recalculate data from an underlying data source for each query. To design these aggregations, you can use the Aggregation Design Wizard. This wizard guides you through the following steps:
Selecting standard or custom settings for the storage and caching options of a partition, measure group, or cube.
Providing estimated or actual counts for objects referenced by the partition, measure group, or cube.
Specifying aggregation options and limits to optimize the storage and query performance delivered by designed aggregations.
Saving and optionally processing the partition, measure group, or cube to generate the defined aggregations.
After you use the Aggregation Design Wizard, you can use the Usage-Based Optimization Wizard to design aggregations based on the usage patterns of the business users and client applications that query the cube.
What is perspective, have you ever created perspective?
Perspectives are a way to reduce the complexity of cubes by hidden elements like measure groups, measures, dimensions, hierarchies etc. It’s nothing but slicing of a cube, for ex we are having retail and hospital data and end user is subscribed to see only hospital data, then we can create perspective according to it.
What is deploy, process and build?
Bulid: Verifies the project files and create several local files.
Deploy: Deploy the structure of the cube(Skeleton) to the server.
Process: Read the data from the source and build the dimesions and cube structures
Elaborating the same is given below.
Build: Its is a used to process the data of the cube database. Build is a version of a program. As a rule, a build is a pre-release version and as such is identified by a build number, rather than by a release number. Reiterative (repeated) builds are an important part of the development process. Throughout development, application components are collected and repeatedly compiled for testing purposes, to ensure a reliable final product. Build tools, such as make or Ant, enable developers to automate some programming tasks. As a verb, to build can mean either to write code or to put individual coded components of a program together.
Deployment: During development of an Analysis Services project in Business Intelligence Development Studio, you frequently deploy the project to a development server in order to create the Analysis Services database defined by the project. This is required to test the project.
for example, to browse cells in the cube, browse dimension members, or verify key performance indicators (KPIs) formulas.