Free Microsoft Data Engineering DP-700 Actual Exam Questions - Question 8 Discussion
Notebook1 reads data into a DataFrame from a table named Table1 and applies transformation logic.
The data from the DataFrame is then written to a new Delta table named Table2 by using a merge
operation.
You need to consolidate the underlying Parquet files in Table1.
Which command should you run?
If we think about the purpose of each option, VACUUM (A) mainly removes old files no longer needed, so it’s not really about consolidating files. BROADCAST (B) and CACHE (D) are about query performance, not file management. So, even if we don’t know for sure that Table1 is Delta, the only command focused on merging small files into bigger ones is OPTIMIZE (C). Does anyone know if Fabric enforces tables to be Delta by default? That could settle this clearly.
A/B? VACUUM (A) removes old files but doesn’t merge Parquet files, so probably not that. BROADCAST (B) has nothing to do with file consolidation; it’s for join optimization. OPTIMIZE (C) is specifically for merging small files in Delta tables, which sounds exactly like what’s needed here. CACHE (D) just puts data in memory, not physical file consolidation. So between those, C still seems the way to go given the goal is consolidation of Parquet files.
C. OPTIMIZE fits best since it compacts small files into bigger ones, improving read performance. VACUUM is just for cleanup, so it won’t help with consolidation here.
It’s C because VACUUM only cleans up old files, and CACHE just stores data in memory. OPTIMIZE is the one that consolidates small Parquet files in Delta tables, so it fits here.
Makes sense to go with C since VACUUM just removes old files, not merges them. OPTIMIZE is the one that really compacts small files into bigger ones for better performance. C it is.
C (OPTIMIZE also improves query performance by reducing file count)
Maybe C since OPTIMIZE merges small files into larger ones.