DBMS Mid
Which symbol is a wildcard representing any number of character - * - <> - & - #
*
tables in ____ exclude transitive dependencies
3NF
Aggregate functions include
AVG COUNT MAX MIN SUM
In a _____________, rectangles represent entities and display their attributes; lines represent relationships between connected entities
Entity- Relationship Diagram
To add new record(row) to a table, you use the
INSERT command
to save query results from a view to a new table, use the ..
INTO clause
_____,____ and ____ work on both numeric and textual data.
count, max, and min
it is good practice to avoid...
spaces or special characters in table or field names
big data can be
structured and unstructured
Moving from ____ to ____ separates attributes into multiple, smaller tables that are functionally dependent on only the primary key field of a given table
1NF, to 2NF
What is the difference between a third normal form and fourth normal form table? a. A 4NF table has no alternate keys. b. A 4NF table has no foreign keys. c. A 4NF table has no multivalued dependencies. d. A 4NF table has no primary dependencies
A 4NF table has no multivalued dependencies.
If B is functionally dependent on A, what can you also say? a. A functionally determines B b. A functionally determines another attribute in the table c. B functionally determines A d. B does not determine any other attribute
A functionally determines B
Which of the following statements is true about a one-to-many relationship - Every primary key field participates on the "one" side - Every foreign key field participates on the "one" side - Every Primary key field participates on the "many" side - Every foreign key field participates on the "many" side
Every foreign key participates on the "many" side
Which SQL keywords start an SQL statement to append a new record to a table
INSERT INTO
Which of the following statements is correct? - User data cannot be combined and shared amount authorized users - Database users should each work on their own copy of the database - In a flat-file environment, data is partitioned into several disjointed systems, lists, and files - Controlling redundancy is easier in an flat file than in a database
In a flat-file environment, data is partitioned into several disjointed system, lists and files
Which of the following best describes functional dependence -It describes the relationship of attributes in an entity -It describes the relationship of tuples in an entity -It describes the relationship of entities as compared to other entities -It describes the relationship of unnormalized data to 1NF
It describes the relationship of attributes in an entity
Which of the following is a characteristic of a table that is in first normal form? a. It doesn't contain repeating groups. b. It has at least two foreign keys. c. It doesn't have a primary key d. There are no alternate keys
It doesn't contain repeating groups.
to select records that match a pattern, use the ___ operator in the ___ clause
LIKE, WHERE
you can precede a single condition with the _____ to negate a condition
NOT
With _________, only one criterion must evaluate true order for a record to be selected and with ___________, All criteria must be evaluate true in order for a record to be selected
OR criteria, AND criteria
A __________ can store information about multiple types of entities and the relationships among the entities
Relational database
Which of the following is not true about a one-to-many relationship? a. The table on the "one" side is also called the parent or left table. b. The table on the "one" side may or may not have related records in the "many" table. c. The table on the "many" side may have orphan records, especially if referential integrity is not enforced. d. The table on the "one" side may have orphan records.
The table on the "one" side may have orphan records.
What does it mean to enforce referential integrity on a not to many relationship
You may not create orphan records by entering a phony foreign key value in the many table
the new table created by the make-table query is
a copy of the selected data.
a __________ is a set of rules, calculations, and assumptions used to solve a problem
algorithm
If there is more than one possible choice for the primary key, and one of the possibilities is chosen to be the primary key. What are the others called? a. canceled keys b. alternate keys c. nonkey attributes d. contributory keys
alternate keys
large volume of data produced by every digital process, system, sensor, mobile device and social media exchange
big data.
What is each key that meets the criteria for a primary key called? a. alternate key b. candidate key c. functional key d. normal key
candidate key
Which of the following is a column or collection of columns on which all columns in the table are functionally dependent? a. index key b. candidate key c. major key d. special key
candidate key
What is an alternate key? a. foreign key b. primary key c. column that could be a primary key but was not chosen d. row that could be a primary key but was not chosen
column that could be a primary key but was not chosen
which of the following is not a technique that would be used in the process of developing a relational database -Normalize the data -Review existing data forms and reports - Interview those who use the data to understand business rules -combine all attributes into one large table
combine all attributes into one large table
process of creating entities, attributes, and relationships between the tables of data
database design phase
a ____ unintended loss of data due to deletion of other data
deletion anomaly
key factors for healthy relational database systems include
design, security, and talent
The union operator generally removes...
duplicate rows.
In SQL SELECT queries,_____ are listed in the SELECT clause, ____are listed in the FROM clause, and ____ are listed in the WHERE clause
fields, tables, conditions
_____ is a formal name given to the basic idea of how attributes depend on or relate to other attributes in a relation
functional dependence
what are the three types of modification anomalies?
insertion, update and deletion
a ________ creates a new table in the current or another database with the records selected by a query
make-table
a ______ allows you to enter criteria when you run the query, as opposed to placing it in the design grid
parameter query
Second normal form can be defined as a table that is in first normal form but that contains no ____. a. partial dependencies b. alternate keys c. nonkey columns d. interrelation constraints
partial dependencies
When the ____________________ of a table is a single column, the table is automatically in second normal form.
primary key
Which of the following can be defined as a column (or collection of columns) A such that all other columns are functionally dependent on A and no subcollection of the columns in A has this property? a. functional key b. composite key c. primary key d. declared key
primary key
in an E-R diagram, what represents entities?
rectangles
Which term can be described as the duplication of data and storing data in multiple locations
redundancy
The ERM emphasizes what part of a relational database
relationships
in an E-R diagram, what do lines represent?
relationships between connected entities.
_____ is traditional in its retrieval and storage DBMS
structured data
when placing one query inside another, the inner query is called the ____
subquery
___ and ___ only work on data in a numeric field
sum or avg
Which normal form has an additional condition that the only determinants that the table contains are candidate keys?
third NF
If you convert a collection of tables to an equivalent third normal form collection of tables, what problems do you remove? a. those arising from multivalued dependencies b. those arising from functional dependencies c. those arising from inappropriate null values d. those arising from incomplete deletions
those arising from functional dependencies
how is the relationship implemented in a relational database?
through common columns in the tables
Which of the following is NOT true about a relation in a two-dimensional table?
two or more columns can share the same name
Which command creates a table containing all rows that are in either or both of two tables?
union
What is a table that contains a repeating group called? a. normalized relation b. unnormalized relation c. nominal relation d. non-nominal relation
unnormalized relation
structure in which a field may have multiple values
unnormalized relation
not easily interpreted and not organized, includes metadata
unstructured data.
what two commands can be used to update the values of an existing field?
update and set
What do you call a data inconsistency that results from data redundancy or the use of inappropriate nulls? a. update anomaly b. insertion anomaly c. deletion anomaly d. relational anomaly
update anomaly
a _____ is marked by inconsistencies that result from data redundancy
update anomaly
When is a 1NF table automatically a 2NF table?
when the primary key contains only a single column
when a database has duplicate column names, how do you differentiate those columns?
write both table name and column name, separated by a period. (known as qualifying)
When using both a WHERE and HAVING clause in the same query design, ____ should always come first.
WHERE
Which of the following is not a constraint on the primary key field for a table -There may be no null values -All values must be unique All values must have a matching value in the foreign key field of the table in which it has a one-to-many relationship -All values must contain data within the data type assigned to that field
All the values must have a matching value in the foreign key field of the table in which it has a one-to-many relationship
Which SQL operator can be rewritten with >= AND <= operators
Between
3rd normal form is sometimes referred to as
Boyce-Codd form
Which of the following is not a benefit of the database normalization process -Redundant data is minimized -Data is simplified into only the important attributes Data is more accurate -Data is more consistant
Data is simplified into only the important attributes
How are entities represented in a relational database
Each entity is stored as a table
Which of the following is not a characteristic of a healthy relation -Each column has a distinct name (technically called the attribute name) - Each intersection of a row and column in a table may contain more than 1 value - all values in a column are values of the same attribute - the order of the rows and columns are not important
Each intersection of a row and column in a table may contain more than one value