Databricks Certified Data Engineer - Associate
Get started today
Ultimate access to all questions.
A data engineer has joined an existing project and they see the following query in the project repository:
CREATE STREAMING LIVE TABLE loyal_customers AS
SELECT customer_id -
FROM STREAM(LIVE.customers)
WHERE loyalty_level = 'high';
CREATE STREAMING LIVE TABLE loyal_customers AS
SELECT customer_id -
FROM STREAM(LIVE.customers)
WHERE loyalty_level = 'high';
Which of the following describes why the STREAM function is included in the query?
Real Exam
Community
KKeng
A
The STREAM function is not needed and will cause an error.
B
The table being created is a live table.
Explanation:
Explanation
The STREAM() function is used in Databricks SQL to indicate that the source table (LIVE.customers) is a streaming live table.
Here's why option C is correct:
-
Streaming Live Tables: In Databricks Delta Live Tables (DLT), there are two main types of tables:
- Streaming Live Tables: Process streaming data incrementally
- Live Tables: Process batch data
-
STREAM() function purpose: When you use
STREAM(LIVE.table_name), you're telling DLT that:- The source table (
customers) is a streaming source - You want to read from it as a streaming source
- This enables incremental processing of data
- The source table (
-
Context in the query: The query is creating a
STREAMING LIVE TABLEcalledloyal_customers. To create a streaming table from another table, that source table must also be a streaming source, hence the need forSTREAM(LIVE.customers). -
Why other options are incorrect:
- A: The STREAM function is needed and will not cause an error when used correctly with streaming tables
- B: While the table being created is indeed a live table, this doesn't explain why STREAM function is needed
- D: This describes a different scenario where a PySpark DataFrame is used as a source, not a table reference
- E: This is not what the STREAM function indicates; it's about the nature of the source (streaming vs batch), not about data freshness
In summary, STREAM(LIVE.customers) is used because customers is a streaming live table, and you need to read from it as a streaming source to create another streaming live table.
Comments
Loading comments...