Oracle MySQL 8.0 Database Developer - 1Z0-909 Exam Questions [2026]

QUESTION NO: 1
You are using buffered queries with PHP mysqli in a browser-based web application. Which three are true?

A. Large results can have a negative impact on performance. B. Results are sent to the calling PHP process for buffering. C. Buffered queries are enabled by default. D. Additional queries on the same session are blocked until the result set is released. E. Buffered queries should be used on large tables when the result size is unknown. F. Results are sent from the server to the browser for buffering. G. Buffered queries must be explicitly enabled using mysqliuseresult.

Correct Answer: A,E,G

QUESTION NO: 2
The meeting table stores meeting schedules with participants from five continents. The participants' details are stored in another table.

You need to adjust the start_time and duration columns for optimal storage. What datatype changes would achieve this?

A. start_time TIMESTAMP duration TIME B. start_time TIMESTAMP duration TIMESTAMP C. start_time TIME duration TIME D. start_time DATETIME duration DATETIME E. start__time DATETIME duration TIME

Correct Answer: D

QUESTION NO: 3
Examine this statement which executes successfully:
CREATE TABLE 'fshop' ('product' JSON DEFAULT NULL ) ENGINE=InnoDB;
Now, examine a json value contained in the table:
{"name" : "orange", "varieties" : [{"VarietyName":"Clementine", "Origin" : ["PA", "BU"] }, {"VarietyName": "tangerine", "Origin" : ["CH","JP"]>]> Which will cause documents to be indexed over the 'name' key?

A. ALTER TABLE fshop ADD COLUMN name VARCHAR(20) AS (product->' S - name' ) VIRTUAL, ADD KEY idx_name (name) ; B. ALTER TABLE fshop ADD COLUMN name VARCHAR(20), ADD KEY idx_name (name) ; C. ALTER TABLE fshop ADD COLUMN name VARCHAR(20) AS (product-
>* S .varieties. VarietyName ' ) VIRTUAL, ADD KEY idx_name (name.) ; D. ALTER TABLE fshop ADD name VARCHAR(20) AS (JSON_ONQUOTE (product->"S.varieties.VarietyName")), ADD INDEX (name); E. ALTER TABLE fshop ADD COLUMN name VARCHAR(100) AS (product->' S - varieties' ) VIRTUAL, ADD KEY idx_name (name) ;

Correct Answer: E

QUESTION NO: 4
Examine these MySQL Shell statements:

What is the true about the attempts to add document to the collection?

A. First two documents are added, then mismatched field names cause an error. B. First three documents are added, then different number of fields cause an error. C. First two documents are added, then mismatched field names cause a warning. D. All documents are added without any error or warning. E. All documents are added and cause a warning.

Correct Answer: E

QUESTION NO: 5
Examine these statement which execute successfully:

Now, examine this desired output:

Which two queries will produce the out?

A.

B.

C.

D.

E.

Correct Answer: B,D

QUESTION NO: 6
The employee table includes these columns:
e_id INT, e_name VARCHAR (45), dept_id INT salart INT
You must create a stored function, getMaxSalary(), which returns the maximum salary paid for a given department id.
Which statement will create the function?

A.

B.

C.

D.

Correct Answer: C

QUESTION NO: 7
Examine this statement which has executed successfully:

A. Execution performance can be improved by using like instead of RLIKE. B. Execution performance can be improved by, using a composite index with column description as the leftmost prefix column description. C. The statement takes advantage of index description_idx. D. Execution performance can be improved by adding an index on column description. E. No index will improve statement performance.

Correct Answer: A