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100+ Free 1Z0-909 Practice Questions

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Which statement begins a transaction explicitly in MySQL 8.0?

A
B
C
D
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Key Facts: 1Z0-909 Exam

65

Total Questions

Oracle

90 minutes

Time Limit

Oracle

62%

Passing Score

Oracle

$245

Exam Fee

Oracle 2026

7

Topic Domains

Oracle 1Z0-909 syllabus

Pearson VUE

Testing Provider

Oracle

The 1Z0-909 exam contains 65 multiple-choice questions delivered over 90 minutes with a 62% passing score and a $245 USD list fee. It is delivered at Pearson VUE testing centers or via OnVUE online proctoring. The exam covers MySQL 8.0 features including window functions, recursive CTEs, JSON_TABLE, multi-valued indexes, enforced CHECK constraints, descending and invisible indexes, EXPLAIN ANALYZE, and the X DevAPI Document Store.

Sample 1Z0-909 Practice Questions

Try these sample questions to test your 1Z0-909 exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In MySQL 8.0, which JOIN type returns the Cartesian product of two tables when no ON or USING clause is specified?
A.INNER JOIN
B.LEFT JOIN
C.CROSS JOIN
D.NATURAL JOIN
Explanation: CROSS JOIN produces the Cartesian product of the two tables. In MySQL, CROSS JOIN, INNER JOIN, and JOIN are syntactically equivalent, but only CROSS JOIN is conventionally written without an ON clause to express an intentional Cartesian product.
2Which set operator was introduced in MySQL 8.0.31 to return rows that appear in both of two SELECT result sets?
A.UNION
B.INTERSECT
C.EXCEPT
D.MINUS
Explanation: MySQL 8.0.31 added INTERSECT and EXCEPT. INTERSECT returns rows present in both query results, with INTERSECT DISTINCT as default and INTERSECT ALL preserving duplicates.
3Given the query below, what does the WITH clause define? WITH RECURSIVE cte AS ( SELECT 1 AS n UNION ALL SELECT n+1 FROM cte WHERE n < 5 ) SELECT * FROM cte;
A.A temporary table that persists for the session
B.A recursive common table expression generating values 1 through 5
C.A stored procedure that returns 5 rows
D.A view named cte stored in the schema
Explanation: This is a recursive CTE. The anchor member selects 1, and the recursive member adds 1 until n reaches 5, producing the sequence 1, 2, 3, 4, 5.
4Which window function assigns consecutive integers to rows within a partition, restarting from 1 in each new partition, with no gaps for ties?
A.RANK()
B.DENSE_RANK()
C.ROW_NUMBER()
D.NTILE()
Explanation: ROW_NUMBER() assigns a unique sequential integer to each row within its partition, ordered by the ORDER BY clause; ties receive different numbers and there are no gaps.
5What does the LAG(salary, 2) window function return for a given row?
A.The salary value from the row two positions earlier in the partition
B.The salary value from the row two positions later in the partition
C.The sum of the previous two salaries
D.The average of the previous two salaries
Explanation: LAG(expr, offset) returns the value of expr from the row offset positions before the current row within the same partition; LAG(salary, 2) returns the salary two rows earlier.
6Which clause defines the rows considered by a window function within its partition?
A.GROUP BY
B.HAVING
C.Frame clause (ROWS or RANGE)
D.ORDER BY only
Explanation: The frame clause (ROWS BETWEEN ... or RANGE BETWEEN ...) restricts which rows of a partition are visible to functions like SUM, AVG, FIRST_VALUE, and LAST_VALUE.
7Which clause produces a result set containing all subtotal levels plus a grand total for the listed grouping columns?
A.GROUP BY ... WITH ROLLUP
B.GROUPING SETS
C.CUBE
D.PARTITION BY
Explanation: In MySQL 8.0, GROUP BY ... WITH ROLLUP adds super-aggregate rows for each level of the hierarchy plus a final grand-total row. MySQL does not support GROUPING SETS or CUBE syntax directly.
8Which clause filters rows after grouping has been applied?
A.WHERE
B.HAVING
C.GROUP BY
D.ORDER BY
Explanation: HAVING applies predicates to the result of GROUP BY aggregation, allowing conditions on aggregate functions such as HAVING COUNT(*) > 10.
9Which JSON function returns a JSON object built from the supplied key/value pairs?
A.JSON_ARRAY()
B.JSON_OBJECT()
C.JSON_QUOTE()
D.JSON_MERGE_PRESERVE()
Explanation: JSON_OBJECT(key1, val1, key2, val2, ...) returns a JSON object whose properties come from the key/value pairs supplied as arguments.
10What is the difference between the -> and ->> operators on a JSON column?
A.-> returns a JSON value while ->> returns the unquoted string equivalent
B.Both operators return identical values
C.-> works only on arrays; ->> works only on objects
D.->> returns BLOB while -> returns TEXT
Explanation: col->'$.path' is shorthand for JSON_EXTRACT(col, '$.path') and returns a JSON value (JSON-quoted strings). col->>'$.path' is shorthand for JSON_UNQUOTE(JSON_EXTRACT(...)) and returns the unquoted string.

About the 1Z0-909 Exam

The Oracle MySQL 8.0 Database Developer (1Z0-909) certification validates a developer's ability to build, query, and tune MySQL 8.0 databases. It covers SQL fundamentals, JSON and Document Store, stored programs, transactions, query optimization, connectors, and data-driven application patterns.

Questions

65 scored questions

Time Limit

90 minutes

Passing Score

62%

Exam Fee

$245 USD (Oracle (Pearson VUE))

1Z0-909 Exam Content Outline

Major domain

MySQL Schema Objects and Data

Designing tables and views, managing string, numeric, temporal, spatial, and full-text data types, constraints (including enforced CHECK constraints in 8.0), invisible columns, and partitioning.

Major domain

JSON and Document Store

Creating and querying JSON documents, JSON_TABLE with NESTED PATH, JSON_SCHEMA_VALID, multi-valued indexes, MySQL Shell, and X DevAPI collection CRUD.

Major domain

MySQL Stored Programs

Authoring stored procedures and functions, BEFORE/AFTER triggers, scheduled events, error handling with DECLARE HANDLER, SIGNAL, RESIGNAL, GET DIAGNOSTICS, and cursor usage.

Major domain

Query Optimization

Index design (B-tree, descending, functional, invisible, prefix, multi-valued), EXPLAIN and EXPLAIN ANALYZE FORMAT=TREE, optimizer hints, covering indexes, and avoiding SELECT *.

Major domain

Data-driven Applications

Prepared statements, parameter binding, sql_mode tuning, error handling, batching strategies, and result-set patterns including INSERT ... ON DUPLICATE KEY UPDATE and LAST_INSERT_ID().

Major domain

Transactions

START TRANSACTION, COMMIT, ROLLBACK, SAVEPOINT, isolation levels (READ UNCOMMITTED through SERIALIZABLE with REPEATABLE READ default), locking reads with FOR UPDATE/FOR SHARE, and NOWAIT/SKIP LOCKED.

Major domain

Connectors and APIs

Choosing among Connector/J, Connector/Python, Connector/Node.js, Connector/NET, and Connector/ODBC; configuring TLS (sslMode), authentication plugins (caching_sha2_password), and credential management.

How to Pass the 1Z0-909 Exam

What You Need to Know

  • Passing score: 62%
  • Exam length: 65 questions
  • Time limit: 90 minutes
  • Exam fee: $245 USD

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

1Z0-909 Study Tips from Top Performers

1Focus on MySQL 8.0-specific features such as window functions, recursive CTEs, JSON_TABLE, multi-valued indexes, descending indexes, and enforced CHECK constraints.
2Practice EXPLAIN ANALYZE FORMAT=TREE to read iterator plans and verify index usage on real queries.
3Drill X DevAPI collection CRUD in MySQL Shell so you can answer document store questions confidently.
4Memorize default isolation level (REPEATABLE READ), default character set (utf8mb4), and default authentication plugin (caching_sha2_password).
5Use parameterized queries in every connector example to internalize SQL-injection-safe patterns.

Frequently Asked Questions

What is on the Oracle 1Z0-909 exam?

1Z0-909 covers seven domains for MySQL 8.0 developers: Schema Objects and Data, JSON and Document Store, Stored Programs, Query Optimization, Data-driven Applications, Transactions, and Connectors and APIs.

How many questions and how long is the 1Z0-909 exam?

The 1Z0-909 exam has 65 multiple-choice questions and a 90-minute time limit. The passing score is 62%.

How much does the 1Z0-909 exam cost?

The list price is $245 USD. Local pricing varies by region. Retakes are charged at the same per-attempt price.

Is the Oracle MySQL Database Developer certification offered online?

Yes. You can schedule 1Z0-909 at a Pearson VUE testing center or take it from home through OnVUE online proctoring.

How should I study for 1Z0-909?

Combine the official MySQL 8.0 Reference Manual with hands-on practice. Build sample schemas, write recursive CTEs and window functions, exercise JSON_TABLE and multi-valued indexes, and time yourself on practice tests across all seven domains.

Does 1Z0-909 expire?

No. The certification is tied to MySQL 8.0 and does not require periodic recertification, although it remains version-specific.