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Certified Data Engineer Professional Exam - Question 63


A Databricks SQL dashboard has been configured to monitor the total number of records present in a collection of Delta Lake tables using the following query pattern:

SELECT COUNT (*) FROM table -

Which of the following describes how results are generated each time the dashboard is updated?

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Correct Answer: AC

The total count of records is calculated from the Delta transaction logs. Delta Lake maintains a transaction log that records details about every change made to a table, including the number of records in each file. This allows the system to efficiently calculate the total number of records without needing to scan all the data files.

Discussion

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sturcuOption: C
Oct 24, 2023

total rows will be calculated from delta logs

SydOption: C
Nov 4, 2023

Answer C https://delta.io/blog/2023-04-19-faster-aggregations-metadata/#:~:text=You%20can%20get%20the%20number,a%20given%20Delta%20table%20version.

aragorn_bregoOption: C
Nov 21, 2023

Delta Lake maintains a transaction log that records details about every change made to a table. When you execute a count operation on a Delta table, Delta Lake can use the information in the transaction log to calculate the total number of records without having to scan all the data files. This is because the transaction log includes information about the number of records in each file, allowing for an efficient aggregation of these counts to get the total number of records in the table.

sodereOption: C
Dec 18, 2023

Transaction log provides statistics about the delta table.

PearAppleOption: C
Nov 5, 2023

The answer should be C

DileepvikramOption: C
Nov 9, 2023

The answer is C

alexvnoOption: C
Dec 18, 2023

C - transaction logs contains info about files rows count

Ati1362Option: C
Jun 25, 2024

Delta transaction log