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WGU - D426: OBJECTIVE
ASSESSMENT EXAM 2025 BRAND
NEW ACTUAL EXAM WITH ANSWERS.
1. An __________ _____ is a single-column primary key created
by the database designer when no suitable single-column or
composite primary key exists. Usually artificial key values are
integers, generated automatically by the database as new rows
are inserted to the table. Artificial keys are stable, simple, and
meaningless. - correct answer -Artificial Key
2. Dependence of one column on another is called functional
dependence. - correct answer -Functional Dependence
3. ________________ is the repetition of related values in a
table. - correct answer -Redundancy
4. ________ ______ are rules for designing tables with less
redundancy. - correct answer -Normal forms
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5. When the columns of A are a subset of the columns of B, A
always depends on B. Ex: FareClass depends on (FlightCode,
FareClass). These dependencies are called ________. -
correct answer -Trivial
6. Redundancy is eliminated with _______________, the last step
of logical design. - correct answer -Normalization
7. _______________ eliminates redundancy by decomposing a
table into two or more tables in higher normal form. Ex: A table
in first normal form might be replaced by two tables in third
normal form. In principle, normalization decomposes tables to
any higher normal form. - correct answer -Normalization
8. _______________________ ___________ _______ is ideal
for tables with frequent inserts, updates, and deletes. - correct
answer -Boyce-Codd normal form
9. ____________________ means intentionally introducing
redundancy by merging tables. - correct answer -
Denormalization
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10. Heap table
11. Sorted table
12. Hash table
13. Table cluster - correct answer -Databases commonly
support four alternative table structures:
14. In a _______ _______, no order is imposed on rows. -
correct answer -Heap Table
15. ________ ________ optimize insert operations. Heap tables
are particularly fast for bulk load of many rows, since rows are
stored in load order. - correct answer -Heap Tables
16. In a ______ _______, rows are assigned to buckets. A
bucket is a block or group of blocks containing rows. - correct
answer -Hash Table
17. The ___________ function is a simple hash function with
four steps:
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1. Convert the hash key by interpreting the key's bits as an
integer value.
2. Divide the integer by the number of buckets.
3. Interpret the division remainder as the bucket number.
4. Convert the bucket number to the physical address of the
block containing the row. - correct answer -Modulo
18. A _______ _________ is a database operation that reads
table blocks directly, without accessing an index. - correct
answer -Table Scan
19. An ________ _________ is a database operation that reads
index blocks sequentially, in order to locate the needed table
blocks. - correct answer -Index Scan
20. _____ ______, also called filter factor or selectivity, is the
percentage of table rows selected by a query. When a SELECT
query is executed - correct answer -Hit Ratio
21. In a ________ search, the database repeatedly splits the
index in two until it finds the entry containing the search value: -
correct answer -Binary Search
WGU - D426: OBJECTIVE
ASSESSMENT EXAM 2025 BRAND
NEW ACTUAL EXAM WITH ANSWERS.
1. An __________ _____ is a single-column primary key created
by the database designer when no suitable single-column or
composite primary key exists. Usually artificial key values are
integers, generated automatically by the database as new rows
are inserted to the table. Artificial keys are stable, simple, and
meaningless. - correct answer -Artificial Key
2. Dependence of one column on another is called functional
dependence. - correct answer -Functional Dependence
3. ________________ is the repetition of related values in a
table. - correct answer -Redundancy
4. ________ ______ are rules for designing tables with less
redundancy. - correct answer -Normal forms
, Page | 2
5. When the columns of A are a subset of the columns of B, A
always depends on B. Ex: FareClass depends on (FlightCode,
FareClass). These dependencies are called ________. -
correct answer -Trivial
6. Redundancy is eliminated with _______________, the last step
of logical design. - correct answer -Normalization
7. _______________ eliminates redundancy by decomposing a
table into two or more tables in higher normal form. Ex: A table
in first normal form might be replaced by two tables in third
normal form. In principle, normalization decomposes tables to
any higher normal form. - correct answer -Normalization
8. _______________________ ___________ _______ is ideal
for tables with frequent inserts, updates, and deletes. - correct
answer -Boyce-Codd normal form
9. ____________________ means intentionally introducing
redundancy by merging tables. - correct answer -
Denormalization
, Page | 3
10. Heap table
11. Sorted table
12. Hash table
13. Table cluster - correct answer -Databases commonly
support four alternative table structures:
14. In a _______ _______, no order is imposed on rows. -
correct answer -Heap Table
15. ________ ________ optimize insert operations. Heap tables
are particularly fast for bulk load of many rows, since rows are
stored in load order. - correct answer -Heap Tables
16. In a ______ _______, rows are assigned to buckets. A
bucket is a block or group of blocks containing rows. - correct
answer -Hash Table
17. The ___________ function is a simple hash function with
four steps:
, Page | 4
1. Convert the hash key by interpreting the key's bits as an
integer value.
2. Divide the integer by the number of buckets.
3. Interpret the division remainder as the bucket number.
4. Convert the bucket number to the physical address of the
block containing the row. - correct answer -Modulo
18. A _______ _________ is a database operation that reads
table blocks directly, without accessing an index. - correct
answer -Table Scan
19. An ________ _________ is a database operation that reads
index blocks sequentially, in order to locate the needed table
blocks. - correct answer -Index Scan
20. _____ ______, also called filter factor or selectivity, is the
percentage of table rows selected by a query. When a SELECT
query is executed - correct answer -Hit Ratio
21. In a ________ search, the database repeatedly splits the
index in two until it finds the entry containing the search value: -
correct answer -Binary Search
