Looker Interview Questions and Answers

by Nithyanandham, on Dec 22, 2022 4:25:00 PM

Interview Questions (49)

Q1. What is Looker used for?


Looker is a robust Business Intelligence (BI) tool that helps companies develop insightful visualizations. It has a user-friendly, browser-based workflow (so there's no need for desktop software) and allows dashboard collaboration. Users can design interactive and dynamic dashboards, schedule and automate report distribution, set custom data parameters, and employ integrated analytics, among other features.

Q2. Explain about BI


Organizations small and large, carry out several processes or transactions which will result in generating humongous data. The data holds valuable information that could help improve business. That’s where the Business Intelligence tools come into the picture and help us explore data in meaningful ways. Processing the data in time and proper reporting enhances the ability to make more informed and data-driven decisions.

Q3. What do you mean by Looker BI?


Looker's business intelligence software helps in exploring and analyzing data. We can combine data from different sources and create a unified view. We can then build real-time analytics on top of the data and share them easily. It offers great visualizations and drill-down dashboards.

Q4. What are the advantages of Looker BI?


Here are some of the many advantages of Looker BI.

  • It generates a base model so we can work on the relationships 
  • All the employees in an organization can have a centralized view of metrics
  • We can create easy to read dashboards that allow users to find patterns 
  • It connects directly to the database instead of loading the data from it
  • We can share the generated reports across the organization

Q5. How does Looker work?


A unique feature of Looker is its modeling language known as LookML. This lightweight, flexible markup language empowers teams to describe their data's sources, how it's shared, and how it's merged with other data. As a result, everyone in the organization can produce reports and dashboards and access a centralized data source.

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Q6. How is Looker different from Tableau?


Tableau creates visuals from both structured and unstructured data, and it also includes storyboarding and a spatial file connector. Looker allows you to create custom visuals from a library full of blocks with pre-made dashboard and visualization templates.

Q7. What is the Looker Program, exactly?


Looker Program is a cloud-based BI application used for exploring and analyzing data. The tool aids businesses in capturing and analyzing data from a variety of sources and making data-driven decisions.
Looker allows businesses to examine supply chains, quantify customer value, market digitally, interpret customer behavior, and assess distribution operations.

Q8. Why is Looker the best?


Listed below are the benefits of using Looker:

  • There is no need for any desktop software: Looker's 100% browser-based experience eliminates the need to install and maintain desktop client software. Looker's modern and intuitive web-based experience enables content sharing via links, making collaboration a breeze.
  • Designed to work on the cloud: The architecture of Looker takes advantage of the scalability and performance of modern cloud databases. Unlike most of its competitors, Looker doesn't rely on outdated data extracts or a proprietary in-memory design that forces you to anticipate what questions your users will ask.
  • A trusted data model: The Looker platform was created to provide the perfect balance of governance and self-service. Users of all technical levels can interact with and examine centralized, trustworthy data and analytic insights.
  • API enabled data experiences: Looker employs best-in-class APIs, SDKs, and developer tools to create deep pre-built or custom integrations. Organizations will have new chances to incorporate data into workflows, opening up limitless options for updating old systems and procedures.

Q9. Does Looker use SQL?


Looker is a tool for creating SQL queries and submitting them to a database. Looker makes SQL queries using the LookML project, which describes the database's table and column relationships.

Q10. What is the difference between Looker and data studio?


The following parameters help you to know the differences between Looker and Data Studio:

  • Platform Architecture: Along with dashboarding, Looker is a data aggregation tool. It was designed from the bottom up to incorporate a wide range of data sources and give users the ability to aggregate and transform data using LookML.
    While some transformations can be done within Data Studio, you'll be better off doing them in another platform like BigQuery and then consuming them through DataStudio.
  • Permissions: Looker gives you complete control over user and group management, as well as explicit permissions.
    Data Studio's inherent simplicity allows you to regulate who can modify and view a dashboard and utilize a data source.
  • Version Control: Looker connects with GitHub so that several users can collaborate on a data model or dashboard simultaneously, with the ability to govern merging updates and rolling back modifications.
    Although Data Studio wins for ease of use in version control, Looker's flexibility and depth of information are well worth the productivity cost.
  • Data Models and Blending: You can use Data Studio to connect to data sources and create a standalone model. Looker gives you more freedom when combining data sources, transforming data, and creating reusable reporting models. 
    To obtain the same result in Data Studio, all work must be completed first on the underlying data platform. While Data Studio allows for considerable data blending flexibility, the underlying join is a left outer join, frequently the source of inconsistent reporting.
  • Data Caching: Data Studio allows you some control over your data cache by enabling you to decide whether it should query for new data in 15-minute intervals up to 12 hours at the data source level.
    Looker gives you a lot more versatility in fine-tuning refreshes, which means less frustration for users waiting for their reports.

Q11. Is it possible to connect Looker to an Excel spreadsheet?


Although Looker does not connect directly to an Excel spreadsheet, a derived table can be used to transfer data.

Q12. What language does Looker use?


Looker uses a model written in LookML for constructing SQL queries against a database. LookML is a SQL database language used to describe calculations, dimensions, aggregates, and data connections.

Q13. What is a derived table in Looker?


A derived table in Looker is a query whose results are used as simple database tables.Let's imagine we have a database table called orders, which includes a lot of columns. We can create a derived table called customer order summary that contains a subset of the columns from the orders table.

Q14. What databases does looker support?


Looker integrates with Redshift, Snowflake, BigQuery, and 50+ SQL dialects, allowing you to connect to various databases, prevent database lock-in, and manage multi-cloud data environments.

Q15. What is the Looker semantic layer?


LookML, Looker's powerful semantic modeling layer, enables teams to quickly create a uniform data governance framework and empowers users to perform their analysis while staying sure that they are all based on the same single source of truth.

Q16. What is a Looker model?


A model in Looker is made up of several Explores and dashboards that are coupled to each other. A model does not have a distinct "model" parameter, unlike other LookML elements. Any file defines a model in the Looker IDE's Models section (the Develop page). The model name is derived from the unique filename and must be across your instance.
Any explore declarations, and several model-level options are normally contained in a model file.

Q17. In Looker, what are Looks?


Looks are saved visualizations that a business user can build. These single visualizations are built in the Looker's explore section and are used to comprehend and evaluate data. The looks can be shared and reused in a variety of dashboards.

Q18. Is it possible to connect Looker to MongoDB?


Looker has two ways to connect to MongoDB using the MongoDB Connector for BI: 

  • In MongoDB Atlas, using the MongoDB Connector for Business Intelligence. 
  • On the same server as the MongoDB database.

Q19. What is Looker API?


The Looker API is a secure "RESTful" application programming interface for managing and retrieving the data from the Looker platform. You may use the Looker API to create new Looker user accounts, execute queries, schedule reports, and more.

Q20. What are Looker blocks?


Looker Blocks are pre-built data models for typical analytical patterns and data sources. Looker blocks can be used as a starting point for quick and flexible data modeling in Looker, from efficient SQL patterns to fully built-out data models.

Q21. What do you know about the Looker marketplace?


Many types of Looker content, such as Looker Blocks, applications, visualizations, and plug-ins, can be found, deployed, and managed through the Looker Marketplace. By default, the Looker Marketplace feature is turned on.

Q22. What are boards in the Looker?


Looker's Boards help teams discover curated dashboards and Looks. Dashboards and Looks can be pinned to several boards because they are kept in folders. Users can execute the following things with the help of boards:

  • Users may easily access the most relevant information by pinning Looks and dashboards to boards.
  • To add context and direct users to resources, including links and descriptions.

Users will only be able to see boards to which they have been granted access. To see a board, a user must have View access. Users with Manage Access and Edit access can pin dashboards and Looks to the board, and offer context to benefit other users.

Q23. In Looker, how do you visualize?


Looker makes it simple to build visuals and charts from query results. The following steps show how to create visualizations that best show off your data.

  • Create your query and then run it.
  • To begin configuring your visualization choices, select the Visualisation tab.
  • Choose a visualization style that best represents your data. 
  • To change the visualization option settings, click Edit. You can name and arrange chart axes, choose the position and type of each data series, and change the chart color palette.
  • You can further modify your visualization by choosing which dimensions and measures to include.

Q24. In Looker, what is the use of a cross filter?


Users can use cross-filtering to select a data point in one dashboard tile and have all dashboard tiles filter on that value. Cross-filters can be used in conjunction with conventional dashboard filters, and several cross-filters can be built at once.

Q25. Is it possible to connect Looker with Google Sheets?


Through the Looker Action Hub, the Google Sheets action is connected to Looker. Users can choose Google Sheets as a potential destination when sending or scheduling Looks or Explores after the Looker admin has enabled the Google Sheets action in the Action Hub.

Q26. What does LookML stand for?


Looker ML is Looker's language to describe aggregates, dimensions, calculations, and data relationships in a SQL database. Looker ML constructs a model, which Looker then utilizes to create SQL queries to retrieve the precise data you need for your business research.

A Look ML project consists of a model, view, and dashboard files managed using a Git repository. The model includes files that detail which tables to use and how they should be connected. In each table, the view offers instructions on calculating specific parameters. Dashboard files provide data with a visual appeal that makes it easier to understand.

Q27. What is the explore parameter in Looker?


Explore is used as a beginning point for a query in the Looker application. Each Explore can contain joins to other Explores, and each Explore can reference views. In most cases, explore should be defined in a model file.

Q28. How secure is Looker?


Looker uses AES 256 bit encryption to encrypt your database connection credentials and cached data stored at rest. TLS 1.2 is also used to encrypt network data between the Looker platform and users' browsers. IP whitelisting, SSL, SSH, PKI, and Kerberos authentication are just a few of the options for securing connections to your database.

Q29. Describe Looker data actions


Looker takes an advanced approach to analytics, making it simple to build dependable data applications that enable users to explore, evaluate, and comprehend the data they require. Data Actions, based on comprehensive APIs, allow users to do operations in practically any other application from a single Looker interface.

Q30. What are Looker dashboards?


A Looker dashboard is a set of queries displayed as visualizations on a page. Dashboards allow you to integrate essential queries and visualizations into a single executive view on one page. You can alter the dashboard's tiles and add filters to make it more interactive. You can make as many dashboards as you need, tailoring each one to the needs of the people who use them. Looker dashboards are divided into two categories: user-defined and LookML.

Q31. Explain the term SSIS?


The full form of SSIS in SQL Server Integration Services. SSIS is an element of the Microsoft SQL Server that we use to generate the workflows for data migrating tasks. It is an ETL tool used for retrieving data from different sources and, after that, transforms and loads the data into various destinations.

Q32. What are the different kinds of data flows?


There are different kinds of data flows they are:

  • Transformations: The transformation data flow filters the database through different calculations and modifies the data format.
  • Sources: The data sources can be Excel Files, XML files, Flat files, and Relational databases.
  • Destination Files: The destination files can be PDF files, XML files, Flat files, and Relational databases.

Q33. What are the cache modes of Looker?


In Looker, we have three cache modes they are:

  • Fully reserve mode
  • No reserve mode
  • Mostly store mode

Q34. Describe Pivoting


Pivoting is defined as a mechanism of shifting the data from column to row and vice versa. Pivoting assures that no data is abandoned in either column or row while exchanging the same data.

Q35. Describe OLAP?


Online Analytical Processing is an approach that we use to organize multidimensional data.

Q36. List the tools that we deploy for the data analysis?


 For data analysis, we can deploy the following tools:

  • RapidMiner
  • Node XL
  • Tableau
  • Wolfram Alpha
  • Fusion Tables through Google

Q37. Describe Drilling?


Drilling is an approach that we use for studying the data details that is useful. We can also consider it for removing the issues like authenticity and copyright.

Q38. What are the critical steps of an analytics project?


Following are the critical steps of the analytics project:

  • Specifying solutions and problems
  • Data Modeling
  • Data Validation
  • Data Exploration
  • Data Preparation
  • Tracking and implementing the data

Q39. Name the types of Looker blocks?


We have six types of looker blocks, they are:

  • Analytic blocks
  • Data blocks
  • Data tools
  • Embedded blocks
  • Viz blocks
  • Source blocks

Q40. What is the full form of NDTs?


The full form of NDTs is Native Derived Tables. We can create the NDTs by specifying the explore parameter on the base table through desired columns.

Q41. What is the security difference between the Looker and Tableau?


Tableau provides data security at any level.

In Looker, we have to change the security settings based on our requirements.

Q42. What are the Operating systems that Looker supports?


Looker supports the following operating systems:

  • Mac
  • Linux
  • Windows

Q43. What are the differences between DTS and SSIS?


DTS refers to Data transformation services, while SSIS refers to SQL Server Integration Services.

The error handling capabilities of DTS is restricted. SSIS handles plenty of errors regardless of source, size, and difficulty, 
In DTS, we don’t have business intelligence functionality. In SSIS, we have complete business intelligence integration.
DTS does not have a development wizard. SSIS has an excellent development wizard.
DTS supports X scripting. SSIS supports the .NET scripting.


Q44. Differentiate partial cache mode and no-cache mode?


We use no-cache mode when the reference data is very huge for loading into the memory. We use the partial cache mode when the data site is comparatively low. The lookup index in the partial cache mode provides rapid responses.

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