AWS Glue Crawler Single Table Configuration

DEA-C01 By islever Editorial Last updated Oct 12, 2026

Automate data processing by using AWS services.

Short answer

AD Ensure consistent object format, compression, schema, and S3 prefix structure so the crawler infers a single unified table.

Question

A finance company receives data from third-party data providers and stores the data as objects in an Amazon S3 bucket. The company ran an AWS Glue crawler on the objects to create a data catalog. The AWS Glue crawler created multiple tables. However, the company expected that the crawler would create only one table. The company needs a solution that will ensure the AVS Glue crawler creates only one table. Which combination of solutions will meet this requirement? (Choose two.)

Ensure that the object format, compression type, and schema are the same for each object. Correct Answer
Ensure that the object format and schema are the same for each object. Do not enforce consistency for the compression type of each object.
Ensure that the schema is the same for each object. Do not enforce consistency for the file format and compression type of each object.
Ensure that the structure of the prefix for each S3 object name is consistent. Correct Answer
Ensure that all S3 object names follow a similar pattern.

Key Takeaways

Glue crawlers infer schemas from file content; inconsistent formats or schemas across files cause multiple tables, while consistent prefixes group objects logically.

Learn how to configure AWS Glue crawlers to create a single table by ensuring consistent object format, schema, and S3 prefix structure for data stored in Amazon S3.

Common mistake: Many candidates choose AB, believing compression type must be consistent, but Glue handles different compression types within the same format (e.g., .gz, .snappy) if the base format is uniform.

Expert Analysis

Why the Answer Is Correct

To ensure the AWS Glue crawler creates only one table, the underlying data must present a uniform schema and file structure that Glue can interpret as a single dataset. Option A ensures that the object format (e.g., Parquet), compression type, and schema are identical, which guarantees Glue sees a homogeneous dataset. Option D ensures the structure of the S3 object prefix is consistent, which helps Glue treat the objects as part of a single logical partition or dataset rather than separate entities based on path variations.

Why the Other Options Are Wrong

Option B excludes compression consistency, which might lead to issues if Glue cannot handle mixed compressions for the same format seamlessly in all contexts, though less critical than schema. However, Option A is stricter and safer. Option C suggests not enforcing file format consistency, which would definitely cause multiple tables if files were mixed CSV/JSON. Option E is vague; "similar pattern" is insufficient compared to the structural consistency required in D.

Community Comment Notes

Community consensus strongly supports AD. As user teo2157 noted, "Consistent Object Format... Schema, and Prefix Structure" are key. User Salam9 confirmed this matches official practical exam answers. Some users like kailu questioned D, arguing prefix affects partitioning, but in the context of creating a single table vs multiple, consistent prefixing prevents Glue from splitting data into separate tables based on path anomalies.

Exam Strategy

When configuring Glue Crawlers for single-table ingestion, prioritize schema and format uniformity. Always verify that your S3 data layout uses consistent prefixes to avoid unintended table segmentation.

Frequently Asked Questions

Why does compression type matter for Glue crawlers?

While Glue often handles common compressions, strict consistency in A ensures no ambiguity, especially for custom or less common codecs.

Does S3 prefix structure affect table creation?

Yes, inconsistent prefixes can lead Glue to treat objects as separate datasets or partitions, potentially resulting in multiple inferred tables if schema differs across paths.

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Community Votes

83%

17%

83% of anonymous learners picked answer AD. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 4 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 4

teo2157 👍 3

To ensure that the AWS Glue crawler creates only one table and handles the object format, compression type, schema, and prefix structure consistently: Ensure Consistent Object Format, Compression Type, Schema, and Prefix Structure 1. Consistent Object Format: - Ensure that all objects in the S3 bucket are in the same format (e.g., CSV, JSON, Parquet). 2. Consistent Compression Type: - Ensure that all objects use the same compression type (e.g., GZIP, Snappy). 3. Consistent Schema: - Ensure that all objects have the same schema (i.e., the same fields with the same data types). 4. Consistent Prefix Structure: - Ensure that all objects follow a consistent naming convention and prefix structure in the S3 bucket (e.g., s3://your-bucket/path/to/data/).
kailu 👍 1

D focuses on the S3 prefix structure, which affects partitioning but not the creation of a single table. Consistency in file format and schema is much more important in determining how AWS Glue handles the data.
Salam9 👍 1

I have seen this official answer in the practical exam in the AWS Skills builder website
komorebi 👍 1

Answer is AD

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