UST Data Engineer Interview Questions and Answers

Use regular expression to remove special characters from a string

• Use the regex pattern [^a-zA-Z0-9\s] to match any character that is not a letter, digit, or whitespace

• Use the replace() function in your programming language to replace the matched special characters with an empty string

• Example: input string 'Hello! How are you?' will become 'Hello How are you' after removing special characters

Rank assigns unique rank to each row, while dense rank assigns consecutive ranks without gaps.

• Rank leaves gaps in rank sequence if there are ties, while dense rank does not

• Rank function is used to assign a unique rank to each row based on a specified column

• Dense rank function is used to assign consecutive ranks to rows without any gaps

• Example: If there are two rows with rank 1 in a dataset, rank function will assign 1 ...read more

Use Google Cloud Storage to load CSV data into BigQuery

• Upload the CSV file to Google Cloud Storage

• Create a BigQuery table with the appropriate schema

• Use the 'bq load' command to load the data from the CSV file into the BigQuery table

ADF triggers are used in Azure Data Factory to schedule and orchestrate data pipelines.

• ADF triggers enable the automation of data movement and data transformation activities.

• Triggers can be scheduled to run at specific times or based on event-based triggers.

• They can be used to start or stop pipelines, and can be configured with parameters and dependencies.

• Examples of triggers include time-based schedules, event-based t...read more

IR stands for Integration Runtime. Dataset is a representation of data, while linked service is a connection to the data source.

• IR is a compute infrastructure used to provide data integration capabilities

• Dataset is a structured representation of data used in data engineering tasks

• Linked service is a connection to a data source, providing access to the data

• IR enables data movement and transformation between different da...read more

Optimization techniques in Spark

• Partitioning data to optimize data locality

• Caching frequently accessed data

• Using broadcast variables for small data sets

• Using appropriate data structures and algorithms

• Avoiding unnecessary shuffling of data