DataEngPrep.tech
QuestionsBlogStore
Get PDF Bundle
Home/Questions/Cloud/Tools/How would you use Amazon Glue to merge small files?

How would you use Amazon Glue to merge small files?

Cloud/Toolshard0.7 min readPremium
Frequency
Low
Asked at 1 company
Category
179
questions in Cloud/Tools
Difficulty Split
104E|27M|48H
in this category
Total Bank
1,863
across 7 categories
Asked at these companies
Capco
Key Concepts Tested
etlpartitionspark
Expert AnswerPremium
148 wordsInterview-ready
**Why merge small files**: Small files (e.g., <128 MB) hurt Athena/Spark—each file incurs metadata overhead, and many small files cause task explosion. Athena charges per MB scanned; small-file overhead increases effective cost. Target 128–256 MB per file for optimal scan throughput. **Architecture**: Glue ETL job reads source, applies coalesce(N) or repartition(N) based on target file count, writes Parquet/ORC....
The complete answer continues with detailed implementation patterns, architectural trade-offs, and production-grade considerations. It covers performance optimization strategies, common pitfalls to avoid, and real-world examples from companies like Capco. The answer also includes follow-up discussion points that interviewers commonly explore.

Continue Reading the Full Answer

Unlock the complete expert answer with code examples, trade-offs, and pro tips - plus 1,863+ more.

Create Free Account - Unlock 30 Answers
Get PDF Bundle - from $21

Or upgrade to Platform Pro - $39

Engineers who used these answers got offers at

AmazonDatabricksSnowflakeGoogleMeta

Free: Top 20 SQL Interview Questions (PDF)

Get the most asked SQL questions with expert answers. Instant download.

No spam. Unsubscribe anytime.

Related Cloud/Tools Questions

easyWhat are Airflow Operators? Give examples.FreeeasyExplain the difference between Azure Data Factory (ADF) and Databricks.FreeeasyHow do you handle data security and compliance in a cloud environment?FreehardWhat are the key components of AWS Glue, and how do they work together?FreeeasyWhat is Azure Data Factory (ADF), and what are its main components?Free

According to DataEngPrep.tech, this is one of the most frequently asked Cloud/Tools interview questions, reported at 1 company. DataEngPrep.tech maintains a curated database of 1,863+ real data engineering interview questions across 7 categories, verified by industry professionals.

← Back to all questionsMore Cloud/Tools questions →