Databricks Certified Data Engineer - Associate

Explanation

INSERT INTO is the correct SQL keyword for appending new rows to an existing Delta table in Databricks.

Let's analyze each option:

• A. UPDATE: This keyword is used to modify existing rows in a table, not to append new rows. It updates column values of existing records based on specified conditions.

• B. COPY: This is not a standard SQL keyword for data manipulation in Delta tables. While Databricks has a COPY INTO command for loading data from external sources, it's not a standard SQL DML keyword for appending rows to existing tables.

• C. INSERT INTO: CORRECT ANSWER - This SQL keyword is specifically designed to append new rows to an existing table. In Databricks Delta tables, INSERT INTO adds new records to the table while preserving existing data.

• D. DELETE: This keyword removes rows from a table, not appends them. It's used for deleting existing records based on specified conditions.

• E. UNION: This is a set operator used to combine the results of two SELECT statements, not to append rows directly to a table. While you can use UNION in a SELECT statement that feeds into an INSERT, UNION itself is not a DML command for table modification.

Key Points:

• INSERT INTO is the standard SQL DML command for adding new rows to existing tables
• In Databricks Delta Lake, INSERT INTO ensures data consistency and supports ACID transactions
• The syntax is: INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ...) or INSERT INTO table_name SELECT ...
• This operation appends data without affecting existing records in the table