Snowflake Interview Questions and Answers

1. What is Snowflake?
Snowflake is a software-as-a-service (SaaS) analytic data warehouse built specifically for the cloud. It features a unique architecture that allows users to run independent workloads on the same data without contention. Snowflake also supports unlimited virtual warehouses, enabling efficient data processing and analytics

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2. What is Snowflake’s Architecture?
Snowflake employs a patented multi-cluster, shared data architecture designed for the cloud. It integrates storage, compute, and service layers that scale independently. This architecture ensures high performance, elasticity, and flexibility in handling diverse workloads.

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3. What type of tool is Snowflake?
Snowflake is a cloud-based data platform that supports both ETL (Extract, Transform, Load) and ELT (Extract, Load, Transform) processes. It enables users to extract data, stage it in external or internal locations, and then load it into Snowflake tables using optimized commands.

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4. What is Zero-Copy Cloning in Snowflake?
Zero-copy cloning is a Snowflake feature that allows you to create clones of databases, schemas, or tables without physically copying the underlying data. This makes cloning instantaneous and cost-effective.

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5. What are the types of caching in Snowflake?
Snowflake uses three types of caching to optimize performance:

• Query Result Cache: Caches query results to reuse them for identical queries.
• Metadata Cache: Stores metadata for quick access.
• Local Disk Cache: Caches data locally within virtual warehouses.

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6. What is Snowflake Secure Data Sharing?
Snowflake Secure Data Sharing enables businesses to share live data securely and in real-time with other accounts. It supports sharing using Snowflake tables, secure views, and secure functions without requiring data copies.

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7. Can AWS Glue connect to Snowflake?
Yes, AWS Glue can connect to Snowflake. It provides a fully managed environment for data transformation and ingestion, integrating seamlessly with Snowflake for efficient data handling.

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8. How do you create a task in Snowflake?
To create a task in Snowflake, use the CREATE TASK command. Specify the schema, the warehouse for execution, and the SQL statement or stored procedure to run.

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9. What is Fail-Safe in Snowflake?
Fail-Safe is a data recovery feature in Snowflake that allows recovery of dropped or truncated data after the Time Travel period has expired. It is available for seven days and is managed exclusively by Snowflake.

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10. How does Snowflake differ from Redshift?
Snowflake separates storage and compute costs, providing more flexibility, while Redshift bundles these costs together. Additionally, Snowflake’s architecture is more optimized for multi-cloud environments compared to Redshift.

11. What are the security features in Snowflake?
Snowflake ensures data security through the following features:

• End-to-end encryption using managed keys.
• TLS for secure data transmission.
• Region-specific data storage options.
• Transparent key management at no additional cost.

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12. Is Snowflake an ETL tool?
Snowflake supports both ETL and ELT workflows, enabling seamless integration with tools like Informatica, Talend, and Matillion. Its cloud-native capabilities reduce the need for traditional ETL processes by allowing direct data loading.

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13. Briefly explain Snowflake’s Time Travel.
Snowflake’s Time Travel allows users to access historical data for recovery, auditing, and analysis. It helps restore accidentally deleted data and observe historical changes within a specified retention period.

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14. Does Snowflake use indexes?
Snowflake does not use traditional indexes. Instead, it relies on metadata and column statistics to optimize query execution, enabling scalable and efficient performance.

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15. What is the cost structure for Snowflake’s Time Travel?
Time Travel costs depend on the storage required for retaining historical data. Snowflake stores only the differences between updated or deleted data, reducing overall storage costs.

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16. Is Snowflake an OLTP or OLAP database?
Snowflake is an OLAP (Online Analytical Processing) database, optimized for analytical workloads. It uses separate storage and compute resources to efficiently handle large-scale analytics.

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17. What is a Materialized View in Snowflake?
A materialized view in Snowflake stores pre-computed query results, improving the performance of repetitive and complex queries. It refreshes automatically as the underlying data changes.

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18. How does Snowflake ensure data security during transmission?
Snowflake secures data transmission using TLS (Transport Layer Security), ensuring encrypted communication between client applications and the Snowflake server.

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19. What types of data sharing are supported by Snowflake?
Snowflake supports three types of data sharing:

• Functional Unit Sharing: Sharing data between teams or departments.
• Management Unit Sharing: Sharing data between different organizational levels.
• Geographical Sharing: Sharing data across multiple regions.

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20. What are the advantages of Snowflake’s compression?
Snowflake’s compression reduces storage costs significantly. It minimizes storage overhead for data cloning and sharing while optimizing query performance.