Data-Management-Foundations Exam Dumps : WGU Data Management – Foundations Exam

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.

TheALTER TABLEstatement is used to modify an existing database table structure. One common clause isCHANGE, which allows renaming a column and modifying its data type.

Example:

sql

ALTER TABLE Employees CHANGE COLUMN OldName NewName VARCHAR(50);

Option A (Incorrect):DELETE is used to removerows, not alter table structure.

Option B (Correct):CHANGE is avalid clausefor renaming and modifying columns in MySQL and some other databases.

Option C (Incorrect):STOP is not a valid SQL keyword for altering tables.

Option D (Incorrect):AGGREGATE refers to functions like SUM() and AVG(), not table alterations.

Aquery processoris responsible forquery optimization and executionin a database management system (DBMS). It analyzes SQL statements, optimizes execution plans, and ensures efficient retrieval of data.

Option A (Correct):Thequery processoroptimizes queries by analyzing metadata from thesystem catalogto determine the best execution strategy.

Option B (Incorrect):Logging transactionsbefore applying changes is the responsibility of thetransaction manager.

Option C (Incorrect):Translating instructions intofile system commandsis handled by thestorage manager, not the query processor.

Option D (Incorrect):While the query processor helps retrieve results, thedatabaseengineandAPI layerare responsible for returning results to applications.