WGU Data-Management-Foundations Exam With Confidence Using Practice Dumps

ATransaction ManagerensuresACID (Atomicity, Consistency, Isolation, Durability)properties in database transactions. It manages concurrent transactions, ensuring no conflicts occur and logs modifications to support recovery mechanisms.

Option A (Incorrect):Query optimization is managed by thequery processor, not the transaction manager.

Option B (Incorrect):The transaction manager is a component of the database architecture but is not composed of the entire system (query processor, storage manager, etc.).

Option C (Correct):The transaction manager logs transactions like INSERT, UPDATE, and DELETE, ensuring consistency and recoverability.

Option D (Incorrect):Thestorage manageris responsible for translating queries into filesystem commands.

Toadd a primary key constraint after table creation, we use theALTER TABLEstatement.

Example Usage:

sql

ALTER TABLE Employees

ADD CONSTRAINT PK_Employees PRIMARY KEY (EmpID);

Thisaddsa primary key to the EmpID columnafter the table was created.

Why Other Options Are Incorrect:

Option B (CREATE TABLE) (Incorrect):Used for defining constraintsduringtable creation, not after.

Option C (UPDATE) (Incorrect):Modifiesrow values, not constraints.

Option D (INSERT INTO) (Incorrect):Used toadd datato a table, not modify constraints.

Thus, the correct answer isALTER TABLE, as itmodifies table structure to add a primary key constraint.

Binary searchis an algorithm that finds a search value byrepeatedly dividing the search space into two halves. It is commonly used inindexed searches.

Example Usage in Databases:

B-Trees and B+ Trees(used in database indexing) applybinary searchto navigate the index efficiently.

If searching for ID = 50 in asorted list of IDs, binary search:

Splits the list into two halves.

Checks the middle value.

Eliminates half of the dataset.

Repeats until the value is found.

Why Other Options Are Incorrect:

Option A (Table scan) (Incorrect):Readsevery row,much slowerthan binary search.

Option C (Index scan) (Incorrect):Uses indexes but does not necessarily apply binary search.

Option D (Fan-out) (Incorrect):Describesbranching in B-Trees, not searching.

Thus, the correct answer isBinary search, as it repeatedlysplits the indexin two.