Practice Test 1 | Google Cloud Certified Professional Data Engineer | Dumps | Mock Test
Your company uses BigQuery as their main data warehouse. Recently, data team has proposed a new schema for existing tables: They want to modify some column names to a more meaningful ones. You are tasked to help data team apply the necessary changes on BigQuery’s tables schemas. How can you achieve this?
A. Modify column names for each table using ALTER command.
B. Export data for tables with schema changes to Google Storage. Create a new table with the new schema. Import data to new table from Google Storage.
C. Create views on BigQuery tables with new column names.
D. Create a new table in BigQuery with the new schema. Insert data from existing tables to the new tables using INSERT SELECT statement.
Answer A is correct: To rename a column on a table, use the ALTER TABLE RENAME COLUMN DDL statement.
Answer D is incorrect: This method is very long and is not actually changing the column name but creates a new table altogether.
Answer B is incorrect: No need to export data to Google Storage. You can use INSERT SELECT to move data from existing table to new one.
Answer C is incorrect: It is aimed to change the schema’s column names. Creating views may solve selecting from it, but original columns still have same names.
Source(s):
BigQuery – Modifying Table Schemas: https://cloud.google.com/bigquery/docs/managing-table-schemas#change_a_columns_name
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