Online Access Free 1z1-909 Practice Test

Which two statements are true about aggregate functions?

• A.SUM () returns o if there are no rows to aggregate.
• B.AVG () does not allow use of the distinct option.
• C.MAX () returns null if there are no rows to aggregate.
• D.MIN () cannot use distinct when it executes as a Windows function.
• E.COUNT (distinct) returns a count of the number of rows with different values including Null.

Examine these statement which execute successfully:

Now, examine the statements executed in the mysqi command-line client:

What is true?

• A.
• B.
• C.
• D.

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

The collection col contains all episodes for all seasons for a TV show.
Examine this document which has an example of the details for each episode:

Which query returns all expisode names from the first season?

• A.SELECT doc->,,$.name,, FROM col WHERE doc->"$ . season" = "1";
• B.SELECT doc->"$.name" FROM col WHERE doc->"$.season" = "1";
• C.SELECT "S.name" FROM col WHERE "S.season" = "1";
• D.SELECT name FROM col WHERE season = 1;

Examine the appointments table definition which contains one million rows:

Now, examine this statement which executes successfully:

Which statement will improve query performance?

• A.ALTER TABLE appointments add index IX_2(attendant_session_id, created_by)
• B.ALTER TABLE appointments add index IX_3(attendant_id, created_by)
• C.ALTER TABLE appointments add index IX_1(credit,payment)
• D.ALTER TABLE appointments add index IX_4<attendant_id, payment, credit)