Databricks Data Engineer Associate Question 331
Select 3You are working on a Databricks project where you need to update an existing table with the latest data. The table already exists, but you want to completely overwrite its structure and data. In another scenario, you need to update the existing data in a table without changing its schema or structure. Which of the following statements correctly differentiate between the use of CREATE OR REPLACE TABLE and INSERT OVERWRITE?
- A
CREATE OR REPLACE TABLE updates both the schema and data of a table, while INSERT OVERWRITE only updates the data without modifying the schema.
- B
INSERT OVERWRITE can overwrite specific partitions of a table, whereas CREATE OR REPLACE TABLE always replaces the entire table.
- C
CREATE OR REPLACE TABLE is typically used when the table structure needs to be changed, while INSERT OVERWRITE is used when only data updates are required.
- D
INSERT OVERWRITE automatically preserves table properties and configurations, while CREATE OR REPLACE TABLE resets table properties to defaults.
Show answer and explanation
Correct answers: A, B, C
Explanation
CREATE OR REPLACE TABLE is a command used to redefine both the structure (schema) and the contents (data) of a table. It is generally used when the table schema needs to be updated or the table needs to be recreated. On the other hand, INSERT OVERWRITE is used to update or replace the contents of a table, either fully or partially (specific partitions), without modifying its schema. The two commands serve distinct purposes in data engineering workflows.
- A. Correct.
This is correct. CREATE OR REPLACE TABLE allows you to modify both the schema and the data of a table, while INSERT OVERWRITE focuses only on updating the data while keeping the schema intact.
- B. Correct.
This is correct. INSERT OVERWRITE provides the flexibility to overwrite specific partitions of a table, which CREATE OR REPLACE TABLE cannot do. CREATE OR REPLACE TABLE always replaces the entire table, including its structure.
- C. Correct.
This is correct. CREATE OR REPLACE TABLE is used when there is a need to redefine the schema or recreate the table, while INSERT OVERWRITE is used to update or replace data without altering the schema.
- D. Incorrect.
This is incorrect. INSERT OVERWRITE does not guarantee the preservation of all table properties, as some configurations may need to be explicitly set again. CREATE OR REPLACE TABLE, however, resets table properties to their defaults.