Google ACE bq cp Practice Question
You have a BigQuery table with billions of rows. You need to create a new table with the same schema and copy all data from the original table. Which approach is most efficient?
⚠ Common exam trap
ACE often tests the misconception that SELECT * with a destination table is equivalent to a copy, ignoring that it triggers a full scan and query charges.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use bq cp (copy) command.
The bq cp command performs a server-side copy of a table within BigQuery, duplicating both schema and data without exporting or re-importing. It is the fastest and most cost-effective method because no data leaves BigQuery's storage layer. This is the canonical approach for cloning large tables.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use bq load with an empty file to create the table, then insert data row by row.
Why it's wrong here
Row-by-row inserts through bq load execute one streaming or DML operation per row, so billions of rows become billions of operations. This suits small reference tables or incremental single-record additions, not bulk duplication of an existing table.
- ✗
Export the original table to Cloud Storage as Avro, then load into the new table.
Why it's wrong here
Exporting to Cloud Storage and reloading moves every byte out of BigQuery and back, incurring egress, storage and load time on billions of rows. This suits cross-system migration or format conversion, not an in-place copy where the schema already matches.
- ✗
Use bq query --destination_table mydataset.newtable 'SELECT * FROM mydataset.original'
Why it's wrong here
A SELECT * query with a destination table scans and rewrites all data, consuming query slots and bytes billed rather than duplicating metadata. This suits transforming or filtering data during a copy, not a straight schema-identical clone.
- ✓
Use bq cp (copy) command.
Why this is correct
bq cp performs a server-side metadata copy, duplicating the schema and all rows without streaming data through the client, so billions of rows transfer in seconds and avoid the cost and time of a query-based rewrite.
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Google Cloud exam blueprint
This ACE practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the ACE exam.