PCDE Practice Question: Manage a solution that can span multiple database technologies
A Cloud Spanner database has a table 'Orders' with a column 'status'. The development team needs to add a new column 'priority INT64' to the table without downtime. Which statement should the database administrator execute?
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
✓
ALTER TABLE Orders ADD COLUMN priority INT64;
Spanner supports online schema changes that are non-blocking. ALTER TABLE ... ADD COLUMN is the correct DDL statement and executes without locking the table.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
CREATE INDEX idx_priority ON Orders (priority);
Why it's wrong here
This creates an index, not a column.
- ✗
UPDATE Orders SET priority = 0; (no prior column)
Why it's wrong here
Cannot update a column that doesn't exist.
- ✗
ALTER TABLE Orders ADD priority INT64 NOT NULL DEFAULT 0;
Why it's wrong here
Adding a NOT NULL column without a default value is not allowed. A default must be specified if NOT NULL is used, but the question only asks to add a column without downtime; the given statement is incomplete.
- ✓
ALTER TABLE Orders ADD COLUMN priority INT64;
Why this is correct
Correct. This DDL statement adds the column online, non-blocking.
Go deeper
Related to this question
About these practice questions
Courseiva writes every PCDE question from scratch — 1,446 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCDE 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 PCDE exam.