Accenture Application Development Team Lead Interview Questions, Process, and Tips

Snowflake follows a multi-cluster, shared data architecture with separate compute and storage layers.

• Snowflake has a central data repository where all data is stored in a columnar format

• It uses virtual warehouses to separate compute resources from storage, allowing for independent scaling

• Data is stored in multiple micro-partitions, enabling efficient data retrieval and processing

• Snowflake's architecture supports automa

Data warehousing is the process of collecting, storing, and managing data from various sources for analysis and reporting.

• Data warehousing involves extracting data from multiple sources and consolidating it into a central repository.

• It is used for analyzing historical data to make informed business decisions.

• Data warehousing helps in creating a single source of truth for an organization's data.

• Examples of data warehous...read more

Magic commands in Databricks are special commands that provide shortcuts for common tasks and operations.

• Magic commands start with % or %% and are used to perform specific actions in Databricks notebooks.

• Examples include %fs for interacting with the file system, %sql for running SQL queries, and %python for executing Python code.

• Magic commands can also be used to manage clusters, install libraries, and display visualiz

Optimization techniques in Spark and SQL involve partitioning, caching, and using appropriate join strategies.

• Partitioning data to distribute workload evenly

• Caching frequently accessed data to avoid recomputation

• Using appropriate join strategies like broadcast join for small tables

• Avoiding shuffling operations as much as possible

ConcurrentHashMap is a thread-safe version of HashMap in Java, allowing multiple threads to access and modify the map concurrently.

• ConcurrentHashMap uses a technique called 'lock striping' to divide the map into segments, each with its own lock to allow multiple threads to access different segments concurrently.

• It provides better performance than synchronized HashMap by allowing multiple threads to read and write to th...read more