1.1 Prepare and Process Data ASSOCIATE-DATA-PRACTITIONER Practice Questions (Page 4)

Questions 16–20

1. 16expert · hard

   A data team is cleaning a large table in BigQuery that contains customer records. They need to remove duplicate rows based on a composite key (customer_id, email), but only keep the row with the most recent updated_at timestamp. However, the table is very large, and the team wants to minimize query cost. Which approach is most cost-effective?

   • AUse a GROUP BY with MAX(updated_at) and then join back to the original table.
   • BUse a SELECT with ROW_NUMBER() and QUALIFY to deduplicate, then write the result to a new table.
   • CUse a MERGE statement to delete duplicates in place.
   • DUse a self-join to find duplicates and then delete them.
   Reveal Solution Discussion Select an answer first
2. 17foundation · easy

   A company must load data into a data lake and then perform transformations only when building curated datasets for specific analytics use cases. Which data processing approach does this describe?

   • AELT, because raw data is loaded first and transformations happen later in the lake
   • BETL, because transformations are applied before loading into the data lake
   • CEL, because no transformations are ever performed
   • DETLT, because transformations occur both before and after loading
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4. 18foundation · easy

   A data analyst needs to remove duplicate rows from a BigQuery table based on a 'customer_id' column, keeping only the first occurrence. Which SQL clause is essential for this task?

   • ADISTINCT
   • BROW_NUMBER()
   • CGROUP BY
   • DWHERE
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5. 19foundation · easy

   A company needs to transfer 2 TB of data from an on-premises server to Google Cloud Storage. The network has 1 Gbps bandwidth, and the transfer is a one-time migration. Which tool is most appropriate?

   • ABigQuery Data Transfer Service
   • BCloud Data Fusion
   • CTransfer Appliance
   • DStorage Transfer Service
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6. 20foundation · easy

   In Cloud Data Fusion, which component is used to define the logic for cleaning data, such as removing nulls or standardizing formats?

   • ASink
   • BSource
   • CPipeline
   • DTransform
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