Databricks Data Engineer Associate Question 265
Select 3You are working with a Delta Lake table stored in a Databricks workspace. You need to inspect the directory structure of the Delta Lake table to understand the file organization. Which of the following accurately describes the purpose of key directories or files in a Delta Lake table?
- A
The
_delta_log/directory contains transaction logs that track all operations performed on the Delta table. - B
The data files (e.g.,
.parquetfiles) are stored directly in the root directory of the Delta table. - C
The
_delta_log/directory contains the actual data files for the Delta table. - D
Each transaction in the
_delta_log/directory is represented by a JSON file that records the details of the transaction. - E
The
_change_data/directory stores the Delta table's schema information.
Show answer and explanation
Correct answers: A, B, D
Explanation
Delta Lake organizes its files in a specific directory structure. The _delta_log/ directory stores transaction logs that track all table operations, while data files (e.g., .parquet files) are stored in the root directory of the table. Each transaction is logged as a JSON file in the _delta_log/ directory. Understanding this structure is crucial for debugging and optimizing Delta Lake tables.
- A. Correct.
Correct. The
_delta_log/directory contains the transaction logs that track all operations (e.g., inserts, updates, deletes) performed on the Delta table. - B. Correct.
Correct. The data files (e.g.,
.parquetfiles) for a Delta table are stored in the root directory of the table and are referenced in the transaction logs. - C. Incorrect.
Incorrect. The
_delta_log/directory does not store the actual data files; instead, it stores transaction logs. - D. Correct.
Correct. Each transaction in the
_delta_log/directory is represented by a JSON file, which records details such as added and removed files, schema changes, and metadata updates. - E. Incorrect.
Incorrect. Delta Lake does not use a
_change_data/directory. Change data capture (CDC) features exist but are not implemented through such a directory.