MySQL 5.6 Developer

Here you have the best Oracle 1z0-882 practice exam questions

You have 38 total questions to study from
Each page has 5 questions, making a total of 8 pages
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This questions were last updated on November 14, 2024

Question 1 of 38

What are two ways in which normalizing your tables helps improve performance In MySQL?

Smaller table sizes and row lengths improve sorting operations.

Separate tables allow indexing more columns.

Fewer nullable column improve index usage.

Normalizing Improves the performance of innodb_file_per _table.

Correct Answer: A, C

Normalizing tables in MySQL improves performance primarily in two ways. First, breaking down large tables into smaller, more manageable ones reduces table sizes and row lengths, which in turn enhances sorting operations. Secondly, fewer nullable columns resulting from normalization optimize index usage, as indexes are more efficiently used when fewer columns contain null values.

Question 2 of 38

Identity two ways to configure a PHP application to use the UTF8 character set.

mysqli: :query (‘’SET NAMES utfs’’);

mysqli : :set_charset (‘utf8’)

spdo = new PDO (‘’mysql:host=localhost;dbname=test;charset=utfs’’, user’’, ‘’pass’’);

PDO: :set_charset(‘’utf8’’)

Correct Answer: B, C

To configure a PHP application to use the UTF8 character set, you can use the 'mysqli::set_charset' method to set the character set for a MySQLi connection and configure the PDO object to set the character set in the DSN string. Therefore, the correct methods are using 'mysqli::set_charset('utf8')' and setting the charset in the PDO DSN string like 'new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'user', 'pass');'.

Question 3 of 38

Which three are valid identifiers for the user table in the mysq1 database?

myssq1. user

‘mysq1. user’

‘mysq1’. ‘user’

Mysq1. ‘user’

‘’mysq1. User’’

Correct Answer: B, C, D

In MySQL, valid identifiers for database and table names can be enclosed in backticks, single quotes, or used without any quotes provided they adhere to naming rules. Option B uses single quotes around the full identifier 'mysq1. user', which is valid. Option C properly encloses both the database name and table name in single quotes, ensuring the identifier is interpreted correctly. Option D shows a version with a combination of a regular database name and a quoted table name, which is also allowed in some MySQL contexts. Option A contains a typo, which makes it invalid. Option E has improper quotation marks around the identifier, which disqualifies it as a valid identifier.

Question 4 of 38

You have a transaction that queries a table at the beginning of the transaction and performs the same query later.

Which two transaction isolation levels guarantee that you get the same results both times?

Repeatable read

Read committed

Read uncommitted

Single user

serializable

Correct Answer: A, E

To guarantee that you get the same results both times when querying a table at the beginning of a transaction and performing the same query later, the transaction isolation levels that provide this consistency are 'Repeatable read' and 'Serializable'. 'Repeatable read' ensures that if a row is read twice in the same transaction, the values of the columns in the row will be the same both times. 'Serializable' is the strictest isolation level and ensures complete isolation from other transactions, thus guaranteeing consistent query results throughout the transaction. Therefore, these two isolation levels meet the requirement.

Question 5 of 38

In MYSQL 5.6 you have the table t1:

CREATE TABLE t1 (

id int unsigned NOT NULL PRIMARY key) ENGINE = InnoDB;

There are two connections to the server. They execute in this order:

Connection 1> SET TRANSACTION ISOLATION LEVEL REPEATABLE READ;

Connection 1> START TRANSACTION;

Connection 1> SELECT * FROM t1 WHERE id =1;

Connection 2> TRUNCATE TABLE t1;

What happens to the TRUNCATE TABLE command in connection 2?

It immediately proceeds and causes an implicit commit of the transaction in connection1.

It runs concurrently with the transaction in connection 1 as each connection has its own view of the data in the t1 table.

It blocks waiting for a metadata lock until the transaction in connection 1 ends.

It blocks waiting for a table lock until the transaction in connection 1 ends.

Correct Answer: C

When connection 2 attempts to execute the TRUNCATE TABLE command, it must wait for any ongoing transaction that involves the table to complete. In this case, connection 1 has an active transaction that includes a SELECT operation on table t1. As a result, connection 2's TRUNCATE TABLE command will be blocked by a metadata lock until the transaction in connection 1 either commits or rolls back.