Structured Query Language is a database tool that is used to create and access databases to support software applications.

Q2): What is a DBMS?

A database management system (DBMS) is a software system that helps users create, manage, and access data in a database.expand_more It provides an organized way to store, retrieve, and manipulate information.expand_more Imagine a large library filled with bookshelves. A DBMS is like a filing system that keeps all those books organized and easy to find.

Q3): What is RDBMS?

RDBMS stands for Relational Database Management System. RDBMS stores the data in a collection of tables, which are related by common fields between the columns of the table. It also provides relational operators to manipulate the data stored in the tables.

Q4): What are the different joins used in SQL?

Q5): What is the difference between the DELETE and TRUNCATE commands?

Both DELETE and TRUNCATE commands are used to remove data from tables in a database, but they have some key differences

• DELETE: This removes specific rows from a table. You can use a WHERE clause to filter the data and only delete rows that meet the criteria.

• TRUNCATE: This removes all rows from a table. It's like emptying a bucket in one go, as opposed to taking items out one by one

• DELETE is executed using a row lock, and each row in the table is locked for deletion, whereas TRUNCATE is executed using a table lock, and the entire table is locked for the removal of all records.

• DELETE is a DML command, whereas TRUNCATE is a DDL command.

• The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row, whereas TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log.

• To use Delete, you need DELETE permission on the table, whereas to use Truncate on a table, you need at least ALTER permission on the table.

• Use DELETE for selective deletion with control and rollback options.

• Use TRUNCATE for faster removal of all data from a table, but be aware it's permanent.

DELETE FROM Customers WHERE CustomerName='Mahendra';

TRUNCATE TABLE CUSTOMERS;

Q6): What is the difference between the WHERE clause and the HAVING clause?

Both WHERE and HAVING clauses are used for filtering data in SQL queries, but they target data at different stages of the query processing:

WHERE Clause:

• Applied before data grouping.

• Filters individual rows based on a specified condition.

• Can be used with various SQL statements like SELECT, UPDATE, and DELETE.

• Works with single-row functions like UPPER, LOWER, etc.

HAVING Clause:

• Applied after data grouping using the GROUP BY clause.

• Filters groups of data based on a condition applied to aggregate functions (e.g., SUM, COUNT, AVG) calculated on those groups.

• Only usable with SELECT statements.

• Works with aggregate functions like SUM, COUNT, AVG, etc.

We can't use aggregate functions in the WHERE clause unless it is in a sub-query contained in a HAVING clause, whereas we can use an aggregate function in the HAVING clause. We can use a column name in the HAVING clause, but the column must be contained in the group by clause.

In the WHERE clause, the data that is fetched from memory depends on a condition, whereas in HAVING, the completed data is first fetched and then separated depending on the condition.

SELECT * FROM Customers. WHERE Country='Mexico';

SELECT COUNT(CustomerID), Country
FROM Customers
GROUP BY Country
HAVING COUNT(CustomerID) > 5;

Q6):What is a primary key?

A primary key is a column or combination of columns that uniquely identifies each row in a table. It enforces the entity integrity rule in a relational database.

1. No two rows can have the same primary key value.

2. Every row must have a primary key value

3. The primary key field cannot be null

4. Values in primary key columns can never be modified or updated

Q7):What is a foreign key?

A foreign key is a column or combination of columns that establishes a link between data in two tables. It ensures referential integrity by enforcing relationships between tables.

Q8): What is the difference between primary key and unique key?

1. We can have only one primary key in a table, whereas we can have more than one unique key in a table.

2. The primary key cannot have a NULL value, whereas a unique key may have only one null value.

3. By default, a primary key is a clustered index, whereas a unique key is a unique non-clustered index.

4. A Primary Key supports an auto-increment value, whereas a Unique Key doesn't support an auto-increment value

Q9):What is the difference between a primary key and a unique key?

A primary key is used to uniquely identify a row in a table and must have a unique value. On the other hand, a unique key ensures that a column or combination of columns has a unique value but does not necessarily identify the row.

Q9): What is a trigger?

A trigger is a code associated with insert, update, or delete operations. The code is executed automatically whenever the associated query is on a table. Triggers can be useful to maintain integrity in a database.

• Events that trigger them: SQL triggers can be fired by various events, such as:

  • Inserting a new row into a table (INSERT statement)

  • Updating an existing row in a table (UPDATE statement)

  • Deleting a row from a table (DELETE statement)

CREATE TRIGGER prevent_negative_stock

BEFORE UPDATE ON Products

FOR EACH ROW

BEGIN

IF NEW.stock_level - OLD.stock_level < 0 THEN

SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Update would cause negative stock level.'; END IF;

• END;

Q10): What is a stored procedure?

A stored procedure is like a function that contains a set of operations compiled together. It contains a set of operations that are commonly used in an application to do some common database tasks. It acts like a subroutine that you can call and reuse multiple times to perform a particular task.

• Reusability: Once you create a stored procedure, you can call it by its name whenever you need to execute the same set of SQL statements. This saves you time and effort compared to rewriting the statements each time.

• Modularity: Stored procedures break down complex tasks into smaller, manageable units. This improves code organization and maintainability.

• Input Parameters: Stored procedures can accept input parameters, allowing you to customize their behaviour based on the provided values. This makes them more flexible than static SQL statements.

• Security: You can control access to stored procedures using database permissions. This allows you to grant users the ability to execute specific procedures without giving them direct access to the underlying tables.

• Performance: In some cases, stored procedures can improve performance by reducing network traffic. The database server can compile the stored procedure code once and then reuse it for subsequent executions.

  CREATE PROCEDURE GetCustomerById (@CustomerID INT) AS

  BEGIN

  -- Select customer details from the Customers table SELECT * FROM Customers WHERE CustomerID = @CustomerID; END;

Q9): What is the difference between triggers and stored procedures?

Unlike stored procedures, triggers cannot be called directly. They can only be associated with queries.

• Trigger: A trigger fires automatically whenever a specific event occurs in the database, such as inserting, updating, or deleting data in a table. It acts like a reactive measure.

• Stored Procedure: A stored procedure is called explicitly by an application or user using a command EXEC followed by the procedure name. It's invoked intentionally to perform a task.

  | Feature | Trigger | Stored Procedure | | --- | --- | --- | | Invocation | Automatic (based on database events) | Explicit (called by user or application) | | Typical Use Cases | Enforce data integrity and automate actions | Perform calculations, data manipulation, and logic | | Input Parameters | No | Yes | | Return Values | No | Can return value |

  Q10): What are indexes?

  A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and the use of more storage space to maintain the extra copy of data. Data can be stored only in one order on disk. To support faster access according to different values, a faster search, like a binary search for different values, is desired. For this purpose, indexes are created on tables. These indexes need extra space on disk, but they allow faster search according to different frequently searched values.

  CREATE INDEX idx_city ON Customers(City);

Q11): What are clustered and non-clustered indexes?

Clustered indexes are the indexes according to which data is physically stored on disk. Therefore, only one clustered index can be created on a given database table. Non-clustered indexes dont define the physical ordering of data; they define logical ordering. Typically, a tree is created whose leaf points to disk records. B-Tree or B+ trees are used for this purpose.

Q12): What is normalization?

Normalization is the process of organizing data in a database to minimize redundancy and dependency. It involves breaking down a table into smaller tables and establishing relationships between them.

Q13):What are the different types of normalization?

1-The different types of normalization are: First Normal Form (1NF)

2-Second Normal Form (2NF) Third Normal Form (3NF)

3-Boyce-Codd Normal Form (BCNF) Fourth Normal Form (4NF)

4-Fifth Normal Form (5NF) or Project-Join Normal Form (PJNF)

Q14): What is a transaction in SQL?

A transaction is a sequence of SQL statements that are executed as a single logical unit of work. It ensures data consistency and integrity by either committing all changes or rolling them back if an error occurs.

Q15):What is ACID in the context of database transactions?

ACID stands for Atomicity, Consistency, Isolation, and Durability. It is a set of properties that guarantee reliable processing of database transactions.

Atomicity ensures that a transaction is treated as a single unit of work, either all or none of the changes are applied.

Consistency ensures that a transaction brings the database from one valid state to another.

Isolation ensures that concurrent transactions do not interfere with each other.

Durability ensures that once a transaction is committed, its changes are permanent and survive system failures.

Q16):What is a deadlock?

A deadlock occurs when two or more transactions are waiting for each other to release resources, resulting in a circular dependency. As a result, none of the transactions can proceed, and the system may become unresponsive.

Q17):What is the difference between a database and a schema?

A database is a container that holds multiple objects, such as tables, views, indexes, and procedures. It represents a logical grouping of related data. A schema, on the other hand, is a container within a database that holds objects and defines their ownership. It provides a way to organize and manage database objects.
Q18):What is the difference between a temporary table and a table variable?

A temporary table is a table that is created and exists only for the duration of a session or a transaction. It can be explicitly dropped or is automatically dropped when the session or transaction ends.

A table variable is a variable that can store a table- like structure in memory. It has a limited scope within a batch, stored procedure, or function. It is automatically deallocated when the scope ends.

Q19):What is the purpose of the GROUP BY clause?

The GROUP BY clause is used to group rows based on one or more columns in a table. It is typically used in conjunction with aggregate functions, such as SUM, AVG, COUNT, etc., to perform calculations on grouped data.

Q20):What is a view?

A view is a virtual table based on the result of an SQL statement. It allows users to retrieve and manipulate data as if

Tableau servers can run on a multi-node cluster as well as on virtual machines. Here we will be covering installation on a single-node machine

The minimum hardware requirement for the Tableau server (single node) is:

• Processor speed: 8 core, 2.0 GHz or higher processor

• 32-bit/64-bit architecture: 64-bit

• RAM: 32 GB memory

• Hard Disk: 50 GB disk space should be available

Operating system requirements :

• The operating systems that support Tableau server installation are as follows: Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019, CentOS 7, Ubuntu 16.04 LTS, Red Hat Enterprise Linux (RHEL) 7, Oracle Linux 7

Installation Path: The Tableau server gets installed on the system drives where Windows operating system files also exist. If, by default, the system drive is the C drive, then the installation path will be as follows:

• C:\Program Files\Tableau\Tableau Server\packages

• C:\ProgramData\Tableau\Tableau Server

Some organizations install Tableau servers in different locations as well. We can provide a location different from the system drive by browsing the install location, which will automatically add \Tableau Server to it and install the files under it.

Lets now go to installation for version 2023 (2023.2) of Tableau Server.

Step 1: Get the product key for the software using the user ID and password that you must have received while purchasing Tableau. Then go to the Customer Portal and get the product key.

Step 2: Get the admin rights for the computer on which we are installing Tableau software. The developer should be a member of the administrator's group in local users and group management.

Step 3: Get the installation files for the Tableau server. We can download the installation file by visiting Download Tableau Server-Windows

Step 4: Run the installation files with admin rights. The below screen will come up where you can change the installation drive; by default, it will be installed on the system drive.

Step 5: Once we click next, the below page will appear where we can choose the installation type

Step 6: After we click on the install button, the installation process will be kicked off, and once the installation is completed, clicking next will start Tableau Service Manager. It may take some time to start TSM.

Step 7: Once the TSM process gets launched by the setup process, the below screen will come up. We need to log in using the same admin credential which we have used for running and installing the setup.

Step 8: Once we log in to TSM, it will ask for a product key to activate the Tableau server

The product key is used to activate both the server and the license type, which can be user-based or core-based. It requires an active internet connection, but there is an alternative way to activate Tableau offline as well. You can read Activate Tableau Offline

Step 9: The next step is configuring the basic settings on the Tableau server after activation and successful registration of the product key. We can set how we want to authenticate users, either in a local or active directory, by setting under which account.

The tableau server should run, setting the default port and whether we want to include a sample workbook or not.

Step 10: Setting the authentication type is very critical to the entire set-up. By default, the authentication type is local. The other option is active directory authentication. If we select an active directory option, then we need to enter a domain name in the fully qualified name, and in the NetBIOS section, we can enter the domains nickname

Step 11: We can run the Tableau server either under NT AUTHORITY\NetworkService or a custom service account. We need to provide a domain name with the user name for the custom user account.

Step 12: Setting the default port for the Tableau server: By default, it takes port number 80 if there is no other application running on the same port. If the port is not available, we need to find out which other application has claimed port number 80. Usually, IIS runs on the same port. The IT infrastructure team can help us get a new port if 80 is not available.

Step 13: Once we click on the initialize button in step 9, the Tableau server will start saving all the configuration settings set in the previous steps

Step 14: Once the initialization is completed, the below screen will appear and clicking on the continue button will take you to the final step, where you need to configure the administrator user for running the Tableau server.

Step 15: The Tableau server set up at the last step launches a browser and opens a page where we need to set the administrator user for the Tableau server. The administrator takes care of all tasks like managing sites, user administration, groups, and project management. Even changing, any configuration setting can be done only by the administrator. In the case of active directory authentication, the administrator must belong to a user in the same directory. For local authentication, we need to provide a username and password. This account is very critical as it provides a single entry point to the Tableau server in case of any issue on the server.

Step 16: Once we are done with the setting of administrator users, we can log in to the Tableau server using the web interface. We can then start publishing the workbook to the server using Tableau Desktop.

Both Tableau Online and Tableau Server require Tableau Desktop Professional Edition for publishing workbooks (views and dashboards) and data sources.

Tableau Online

1: Hardware and systems maintained by Tableau outside of your firewall.

2: You can purchase and maintain multiple sites and configure users and permissions.

3: Supports live data connections to Amazon Redshift and Google BigQuery, as well as to SQL-based sources hosted on cloud platforms. For a complete list, see Allow Direct Connections to Data Hosted on a Cloud Platform in Tableau Online.

4: Scheduled refreshes for published data: For complete information, see Keep Data Fresh in the Tableau Online Help.

5: For extracts of cloud-based data sources, you can schedule refresh tasks directly on Tableau Online.

6: For extracts of data sources that you maintain on your local network or for Oracle data hosted in the cloud, you can schedule refresh tasks using the online sync client that comes with Tableau Desktop. Schedules can be as frequent as every 15 minutes.

7: You can also update extracts manually using Tableau Desktop, or automate updates using a command-line utility. Select a pre-configured schedule or create a custom schedule.

8: Authenticate users through Tableau ID (email address and password) or configure a site for single sign-on using SAML.

9: No guest access; all users accessing views and dashboards published to Tableau Online must be authenticated.

10: Custom branding: upload your company logo.

Tableau Server

1: You install the software and maintain the systems on your hardware, inside or outside your company firewall.

2: You can create and maintain multiple sites at no additional cost, and you can configure users and permissions.

3: You can schedule refresh tasks for published extracts. Select a pre-configured schedule or create a custom schedule.

4: Can be configured for local authentication, Active Directory integration, trusted authentication, or single sign-on using SAML or Kerberos.

5: Provides a core licensing option, that allows guest access.

6: Supports live connections to your local data sources and Google BigQuery and Amazon Redshift. Supports published extracts.

7: Custom branding: change the logo and the company name that appear in various web browser locations and tooltips.

Q2): What type of sources/data sources did you work on while creating reports/tableau dashboards?

Q3): Did you create reports/dashboards from a data warehouse as a source?

Q4): How can I somehow archive my most valuable workbooks and, at the same time, have version control?

Q5): How can I be notified immediately when my extract fails (or succeeds)?

Q6): Can I remove older workbooks (and archive them) from Tableau Server and, simultaneously, email the owner?

Q7): What calculations (or fields) are in my Tableau workbooks? And how do I grab the actual formula being used?

Q8): Can I take daily snapshots of Tableau Servers database to do some analysis on workbook usage? For example, if I want to know how my published workbook performs over time (or how many views it has received), this will allow for that.

Q9): Can I take daily snapshots of Tableau Servers database to do some analysis on user logins?

Q10): Can I take daily snapshots of Tableau Servers database to do some analysis on data source usage?

Q11): How do I add a maintenance message to notify users of a forthcoming server restart and/or upgrade?

Q12): Can a parameter be used inside another parameter?

Q13): Can we use groups in calculated fields?

Q14): Can we group multiple dimensions using groups?

Q15): How many types of extensions are there in Tableau, and how are they used?

Q16): We are generating a dashboard with a live connection and publishing it on the server, How does the server keep connected with the database to keep the data up to date?

Q17): How many different charts are there in Tableau and other than that, how many have you created?

Q18): What will you do if some country/province (any geographical entity) is missing and displaying a null when you use map view?

Q19): Find the customer with the lowest overall profit. What is his/her profit ratio?

Q20): How do you handle nulls and other special values?

Q21): Is there any difference between sets and groups? Explain with examples?

Q22): How can you display the top five and last five sales in the same view?

Q2): What is Tableau Desktop?

Q3): What is a Tableau server?

Q4): What is Tableau Online?

Q5): What is a Tableau Reader?

Q6): What are Tableau Desktop and Server?

Q7): What databases are working for current projects?

Q8): What is the SQL and Oracle database connection process?

Q9): What are the connection types (live and extract)??

Q10): How do you load (import) the database into Tableau?

Q11): What is the custom SQL usage, and can you work parameters with custom SQL?

Q12: What is the difference between Vizql and custom SQL?

Q13: What is the difference between TWB and TWBX?

Q14: What file type do we use when we have Tableau Reader?

Q15): What is TDE, and how does it work to increase performance?

Q16): How many ways can we increase the performance of the dashboard, workbook, or database?

Q17): How do I check performance recordings in Tableau Desktop? Can you give an example of the dual axis and when we use the synchronized axis?

Q18): What are a waterfall chart, a blended axis, and an individual axis?

Q19: How do I sort the field values in Filter?

Q20) Region fields have values like central, east, south, and west and need west values at the top.

Q21): Types filter, diff b/t Cascading and Context filter?

Q22: What are the new features added to Tableau?

Q23: What are the replacement data sources and references?

Q24): Explain the example of replacing data sources. ?

Q25): What is a formula for diff, diff in%, and total in%?

Q26): What do index, SN, and lookup functions do?

Q27: How do you get the requirements for the project?

Q28: How many tables have you used in the current project?

Q29: How many dashboards have you created in Tableau for your current projects?

Q30): What are the dashboard objects and sizes for your projects?

Q31: How do you validate the reports and dashboards?

Q32: How do I improve the worksheet performance?

Q33): What is data blending, and what is the default join?

Q34): What are the data-blending limitations?

Q35: What are the parameters? Explain to Sanrio.

Q36): What parameters can I use in a tableau and explain the limitations?

Q37: Explain the difference between parameters and filters.

Building a bridge between developers and business stakeholders is a critical function of a business analyst (BA). The business analyst (BA) collects requirements from a variety of stakeholders (such as end users and management) and converts them into requirements that are simple, easy to understand, and well-defined so that the development team can carry them out.

The BA acts as a central point of communication between various stakeholders, ensuring everyone is informed, aligned, and on the same page throughout the project lifecycle.

Q2) What is a Business Requirements Document (BRD)?

A Business Requirements Document (BRD) serves as a project blueprint, describing the business goal. It provides a foundation for understanding what needs to be accomplished and leads the development and implementation process. The BRD is usually established during the early stages of a project, usually working together with stakeholders. methodology

Q3. What is the difference between BRD vs. SRS vs. FRS?

BRD (Business Requirements Document), SRS (Software Requirements Specification), and FRS (Functional Requirements Specification) are all types of requirement documents used in software development. The main difference between them is the level of detail and scope they cover.

• BRD: The BRD serves as a communication tool between business stakeholders and the development team to ensure alignment on the project's purpose and objectives.

• SRS: The SRS is used as a reference for developers and testers to understand the system's behaviour and functionality accurately.

• FRS: The FRS typically includes use cases, scenarios, user stories, and other detailed descriptions of system functionality.

  

Source: BRD vs SRS vs FRS - Detailed Comparison | The Business Analyst Job Description

Q4) Describe the Agile methodology and its relevance to business analysis.

The Agile methodology takes an iterative and incremental approach to project management. The agile technique supports the work of a business analyst by emphasizing cooperation, adaptability, customer orientation, and continual development. Business analysts play an important role in Agile initiatives by bridging the gap between business stakeholders and development teams.

It enables BAs to deliver solutions that meet the ever-evolving needs of stakeholders while ensuring effective use of resources and timely delivery of business value.

Q5) What are some common data modeling techniques used by business analysts?

Business analysts leverage various data modelling techniques to effectively understand, document, and communicate data requirements for projects. Here are some commonly used techniques:

• Entity-Relationship Diagram (ERD): This visual representation depicts entities (data subjects) and their relationships with each other. It helps BAs understand the core data elements and their interconnections at a high level.

• Data Flow Diagram (DFD): This graphical model illustrates the flow of data within a system, showing how data enters, transforms, and exits the system. It helps BAs visualize data processes and identify potential data storage needs.

• Unified Modeling Language (UML) Class Diagrams: While primarily used in software development, UML class diagrams can be valuable for BAs to model complex systems and relationships between entities and their attributes.

Q6) Explain the difference between a business analyst and a project manager.

Both play a crucial role in a project, while a project manager focuses on planning, executing, and monitoring project activities to ensure successful project delivery. A business analyst focuses on understanding business needs, defining requirements, and ensuring solutions align with those needs.

Q7) How do you handle managing team conflicts in a project?

In my perspective, effective communication and conflict resolution skills are essential for solving team problems. I begin by attempting to identify the basic root of the issue and facilitating open discussions to arrive at a solution that benefits all team members and fits in with the project's goals. I also make sure to document any resolutions and follow up to keep track of the problem.

Fetch all the data from different OLTPs, make it coherent (in a consistent manner), load to the Data warehouse, and generate the Reports from the Data Warehouse

Data warehousing is a separate database that is specially structured for reporting and analysis.

Data warehousing contains both current and historical data.

It is also called an OLAP database or reporting database.

Generally, we will define DWH database by using multi-dimensional Dimensional Modeling

Q: What is OLTP?

LTP stands for Online Transactional Process, which stores transactional data. The Operational systems are where the data is put.

Q: What is OLAP?

OLAP stands for Online Analytical Process, which stores analytical data that is used for analysis and reporting. The data warehouse is where we get the data.

Q: What is the need for a data warehouse?

Let us assume ABC bank operates in multiple countries. And let us say Country 1 data is residing in OLTP1, Country 2 data is in OLTP2, and Country 3 data is in OLTP3. If one day ABC Bank requires consolidated reports, we need to go for data warehousing.

Q) Why do we never create reports at the top of OLTPS?

OLTP Systems does not maintain a complete history in order to have better transaction performance. So it is not possible to analyze the data completely for a wide range of.

Q: What are the issues we face when creating reports on top of OLTPS?

We are fetching the data from multiple transactional systems to generate a consolidated report; obviously, it takes some time to get the final consolidated report. As the OLTP systems are highly normalized, to get the report output, we need to join a larger number of tables. Also, it is not recommended to insert and retrieve data from the same system at the same time.

Q) What are the benefits of OLAP?

OLAP will maintain a complete history so that we can make better analyses using complete data. There will be no performance issues because we have complete data from all the transactional sources in the data warehouse. Completely De-Normalized

The databases that are used for reporting and analysis are called OLAP databases.

OLAP databases contain entire organization data.

OLAP database data is summarized.

OLAP databases are designed using multi-dimensional modeling.

OLAP databases are highly denormalized.

Query performance is good in OLAP databases.

Q) ER-Modelling?

Entity Relationship Modeling is used to design OLTP databases. data is highly normalized

Q) Dimension modeling?

Dimensional Modeling is used to design OLAP databases. Dimensional modeling is a particular design methodology of data modeling wherein the goal of modeling is to improve query performance.

Q) Star Schema?

A star schema is a data warehouse database design that contains a centrally located fact table that is surrounded by multiple dimension tables. In the star schema, all the dimensional tables directly connect to the fact table.

Q) Snow-Flex Schema?

A snowflake schema consists of a fact table surrounded by multiple dimension tables that can be connected to other dimension tables. In the snowflake schema, some of the dimensions will not directly connect to the fact table. When dimension tables store a large number of rows with redundancy of data and space is such an issue, we can use the Snowflake schema to save space.

Q) Galaxy Schema?

This schema is viewed as a collection of stars; hence, it is called the Galaxy Schema or the Fact Constellation Schema. In a Galaxy schema, a single dimension table is shared with multiple fact tables.

Q: What is dimension?

A dimension is descriptive data that describes the key performance indicators, known as facts. E.g., product, customer name, date, etc.

Q) 5. What are the different types of dimension tables in the context of data warehousing?

1. Slowly Changing Dimension

2. Conformed Dimension

3. Degenerate Dimension

4. Junk Dimension

5. Role-playing Dimension

6. Static Dimension

7. Shrunken Dimension

Q: What is a fact table?

A fact is something that is measurable or quantifiable. Fact is the metric that business users would use for making business decisions

Q) Difference between fact and Dimension Table?

Q: What is a data mart?

A data mart is an access layer that is used to get data out to users. It is presented as an option for large data warehouses, as it takes less time and money to build. However, there is no standard definition of a data mart, which differs from person to person.

In a simple word, a data mart is a subsidiary of a data warehouse. The data mart is used for the partition of data that is created for a specific group of users.

1. Data marts are a subset of the DWH database.

2. Data marts contain one subject area of information.

3. Data marts are used to improve performance.

4. The creation of data marts is optional in DWH projects.

Types of data marts:

1. Dependent Data Mart.

2. Independent Data Mart

Dependent Data Mart

Independent Data Mart

Microsofts Power BI is a common business intelligence tool used by business analysts and professionals. Microsoft Power BI is a data visualization platform used primarily for business intelligence purposes. It is designed to be used by business professionals with varying levels of data knowledge It comes as a package of three major components

1: Power BI Desktop

2: Power BI Service

3:Power Bi Mobile Apps

Q2) What are the major components of Power BI?

Microsoft Power BI technology consists of a group of components, such as:

1:Power Query

Power Query is an ETL software in Power BI. Power Query is one of the software programs in Power BI Desktop that is used for performing ETL activities or data preparation activities in Power BI.

M (mashup) is the language used in Power Query behind every GUI option to perform the ETL activities.

A) Power Query Editor User Interface Contains 5 Major Sections

1. Ribbon: the ribbon navigation experience, which provides multiple tabs to add transforms, select options for your query, and access different ribbon buttons to complete various tasks.

   

   The ribbon is the component where you find most of the transforms and actions that you can do in the Power Query editor.

2. Queries pane: a view of all your available queries.

3. Current view: your main working view, which by default displays a preview of the data for your query. You can also enable the diagram view along with the data preview view. You can also switch between the schema view and the data preview view while maintaining the diagram view.

4. Query settings: a view of the currently selected query with relevant information, such as query name, query steps, and various indicators.

5. Status bar: a bar displaying relevant and important information about your query, such as execution time, total columns and rows, and processing status. This bar also contains buttons to change your current view.

   Q3) What is Power View?

Power view is one of the PowerBI desktop software programs that is used to create reports in Report View by taking the dataset as a source.

Q4) What is a power pivot?

Power Pivot is a data modelling technology that lets you create data models, establish relationships, and create calculations. With Power Pivot, you can work with large data sets, build extensive relationships, and create complex calculations

Q5) What is a power map?

With Power Map, you can plot geographic and temporal data

Q6) What is the Power Bi Mobile App?

You can easily and quickly access your Power BI reports and dashboards with the Power BI mobile app on your smartphone. This application, which functions similarly to Power Bi services, lets you browse your workspace and quickly access your report and dashboard. It also allows you to connect with your data, get insights, and receive alerts if there are any data changes in the dashboard.

Q7) Where is the data stored in Power BI?

Power BI uses two primary repositories for storing and managing data: data that is uploaded from users is typically sent to Azure Blob Storage, and all metadata as well as artifacts for the system itself are stored in the Azure SQL Database.

Q8) What types of connection modes are there in Power BI?

There are three connection modes: import, direct query, and live connection. In import mode, all data is imported into Power BI Desktop, so pbix will contain data. In the case of DQ/LC, the query is sent to the data source to obtain the data, so the data will not be saved to pbix.