Top 1000+ Database Subject Mcqs Pdf Download Set No 19
901. A table can be logically connected to another table by defining a ____.
- hyperlink
- primary key
- common attribute
- logic key
902. A relational operator that yields values from all rows in a table is known as the ____ operator.
- DIFFERENCE
- SELECT
- PRODUCT
- PROJECT
903. A relational operator that yields all values from selected attributes is known as the ____ operator.
- DIFFERENCE
- SELECT
- PRODUCT
- PROJECT
904. A relational operator that allows for the combination of information from two or more tables is known as the ____ operator.
- SELECT
- JOIN
- PROJECT
- DIFFERENCE
905. In a relationship, when a primary key from one table is also defined in a second table, the field is referred to as a ____ in the second table.
- combined key
- primary key
- redundant field
- foreign key
906. A relational operator that yields all possible pairs of rows from two tables is known as the ____operator.
- UNION
- DIFFERENCE
- INTERSECT
- PRODUCT
907. A primary key that consists of more than one field is called a ____ key.
- composite
- group
- secondary
- foreign
908. A relational operator that yields all rows in one table that are not found in the other table is the operator.
- UNION
- DIFFERENCE
- INTERSECT
- PRODUCT
909. The short Date format is ____.
- DD-MM-YY
- MM/DD/Y
910. A field that consists of integer values is a ____ type field.
- Date/Time
- Memo
- Yes/No
- Numeric
911. Which of the following statements concerning the primary key is true?
- All primary key entries are unique.
- The primary key may be null.
- The primary key is not required for all tables.
- The primary key data do not have to be unique.
912. Which of the following is NOT an allowable operation for a date field?
- Compare two dates
- Multiply two dates
- Convert a date from its internal representation to a different presentation format
- Create a date by adding or subtracting a number of days from a given date
913. In general terms, the ____ key is an attribute (or combination of attributes) that uniquely identifies any given entity.
- indexed
- foreign
- primary redundant
914.In the context of a database table, the statement “A determines B” indicates that ____.knowing the value of attribute A, you cannot look up the value of attribute B B. you do not need to know the value of attribute
- in order to look up the value of attribute B
- knowing the value of attribute
- you can look up the value of attribute A
- knowing the value of attribute A, you can look up the value of attribute B
915. A ____ is any key that identifies each entity uniquely. It functionally determines all of the entity’s attributes.
- super key
- foreign key
- primary key
- combined key
916. It might take more than a single attribute to define functional dependence; that is, a key may be composed of more than one attribute. A multi-attribute key is known as a ____ key.
- primary
- composite
- super
- foreign
917. The table is said to exhibit ____ integrity.
- referential
- enforced
- entity
- key
918 .In a sophisticated application development software, nulls can create problems when using functions such as
- COUNT
- COUNT and AVERAGE
- SUM
- D. COUNT, SUM, and AVERAGE
919. We can describe a link by observing that ____.
- a primary key of one table appears again as a primary key in a related table
- a foreign key of one table appears again as a foreign key in a related table
- a primary key of one table appears again as a foreign key in a related table
- a foreign key of one table appears again as a primary key in a related table ANS
920. User rights information is stored in
- Physical database
- Catalog
- Logical database
- Buffer
921. Making a change to the conceptual schema of a database but not affecting the existing external schemas is an example of
- Physical data independence.
- Concurrency control.
- Logical data independence.
- Functional dependency
922. Identify the constraint that limits the values that can be placed in a column.
- NOT NULL
- CHECK
- FOREIGN KEY
- UNIQUE
923. Which of the following enforces a relation into 1st normal form?
- The domain of attribute must include only atomic values.
- Every non-key attribute is fully functionally dependent on primary key
- non-key attribute is non-transitively dependent on primary key.
- Every non-key attribute is partially dependent on super key
924. Controlling redundancy in a database management system DOES NOT help to
- avoid duplication
- avoid unnecessary wastage of storage space
- avoid unauthorized access to data avoid inconsistency among data
925. Which of the following is CORRECT about database management system’s languages?
- Data definition languages are used to specify the conceptual schema only.
- Data manipulation languages are used to create the databases.
- Data manipulation languages are used for retrieval, insertion, deletion and modification of data.
- Data definition languages are only used to update data in the DBMS.
926. Which of the following is INCORRECT statement concerning the database design process?
- During requirements collection and analysis phase, one can gather the data requirements of
- database users.
- By referring to a high level data model, it is possible to underst and the data requirements of the users, entity types, relationships and constraints.
- Transformation of the high level data model into the implementation data model is called logical design or data model mapping.
- During the logical design phase of internal storage structures, access paths and file organization for the database files are specified.
927. Identify the INCORRECT statement among the given.
- An entity may be an object with a physical existence like a car, a house or an Employee. One cannot consider something which has conceptual existence like a course in a degree program as an
- entity.
- Age can be considered as a single value attribute of a person.
- An entity type describes the schema or intension for a set of entities which share the same structure.
928. Select the correct statement among the following.
- Role names are not technically necessary in relationship types when all the participating entity types are distinct.
- When different entity types participate only once in a single relationship type it is called a recursive relationship.
- Cardinality ratios for binary relationship are displayed on Entity Relationship Diagrams by using a diamond shape notation.
- Partial participation which is also called existence dependency is displayed as a double line connecting the participating entity type to the relationship.
929.In a relation, which of the following refers by the Structural constraints?
- finding the owner entity type relevant to a given entity type.
- the number of relationship instances which an entity can participate in.
- the role that a participating entity from the entity type plays in each relationship instance.
- the constraints applicable in granting access to tables, columns and views in a database
- schema
930. Identify the correct statement.
- Entity integrity constraints specify that primary key values can be composite.
- Entity integrity constraints are specified on individual relations.
- Entity integrity constraints are specified between weak entities.
- When entity integrity rules are enforced,
- a row in one relation that refers to another relation must refer to an existing tuple.
931.Which of the following is true about relational schema?
- The sequence of columns is significant
- The sequence of rows is significant.
- Contains only derived attributes. Values are atomic.
932. Identify the factor which enforces a relation in 3NF?
- Every non-key attribute is fully functionally dependent on primary key
- Every non-key attribute is partially dependent on super key
- The domain of attribute must include only atomic values. Every non-key attribute is non-transitively dependent on primary key.
- all
933. If W, X, Y and Z are attributes of a relation, which of the following inference rules for functional dependencies is correct?
- If (X, Z) -> Y then X -> Y and Z -> Y. If X -> Y and X -> Z then X -> (Y, Z).
- If X Y then Y -> X
- If X -> Y then (X, Z) -> (Y,W).
- all
934. Which of the following is not a benefit of normalization?
- Minimize insertion anomalies
- Minimize deletion anomalies
- Minimize updating anomalies
- Maximize redundancy
935. A candidate key that does not have a null value and is selected to uniquely identify all other attribute values in any given row is called a ____.
- Super key
- candidate key
- primary key
- secondary key
936. What is sub-type discriminator?
- The subtype discriminator,
- you will add to the super type table for a disjoint condition (or non-overlapping condition).
- The purpose of the subtype discriminator is to help you avoid having to
- write sub queries or joins just to find information
- Such as the names of all AARP members.
- But when subtypes overlap, this simple discriminator structure doesn’t work.
937. In which condition a relation in first normal form, automatically turns into the second normal form?
- Those that do not depend upon the combination
- key, are moved to another table on whose key they depend on.
938. Structures which do not contain combination keys are automatically in second normal form. State the two major benefits of referential integrity constraints?
- Often, in relational database,
- to ensure that a value that appears in one relation for a given set of attributes also appears for a certain set of attributes in another relation.
- This condition is called Referential integrity (RI).
- It is the concept of relationships between tables, based on the definition of a primary key and a foreign key.
939. The following summarize the benefits of referential integrity
- Ensure data integrity and consistency base on primary key and foreign key ..
- Increases development productivity, because it is not necessary to code
- SQL statements to enforce referential constraints,
- the data RDBMS automatically enforces referential integrity.
940. What is table.
- it consist of rows and columns.
- The columns save the qualities that describe the group of data.
- Every row contains full record of a particular data.
- Every table has a Primary key which denotes
- all
942. Consider the following two columns. The Column A consists of terms related to the ER model and Column B consists of terms used in the relational model.?
- The terms in Column A have been mapped to Column B so that it corresponds to the mapping process of the ER Model into a Relational model.
- Map
- each of the entry in column A to the appropriate entry
- in column B
943. Relation
- A relation is a table that holds the data we are interested in.
- It is two-dimensional and has rows and columns.
- none
944. Each entity type in the ER model is mapped into a relation.
- The attributes become the columns.
- The individual entities become the rows.
- 1-entity type relation
- 2key attributes>>>primary or secondary keys
- 3->composite attribute-> relation and foreign keys )
945. Why do we need to know the specific data model of any DBMS?
- all.
- Hierarchical Model
- Network Model Relational Model
- Data in a series of records, which have a set of field values attached to it. It collects all the instances of a specific record together as a record type.
- These record types are the equivalent of
946.Type of t
- Logical modeling
- Physical modeling
- all
947. logical model
- Logical modeling deals with gathering business requirements and converting those requirements into a model.
- The logical model revolves around the needs of the business, not the database
- All
- needs of the business are used to establish the needs of the database.
- Logical modeling involves gathering information about business processes, business entities
948. Diagram
- The diagrams produced should show the processes and data that exists, as well as the relationships between business processes and data.
- Logical modeling should accurately render a visual
- representation of the activities and data relevant to a particular business.
- The diagrams and documentation generated during logical modeling is used to determine whether the requirements of the business have been completely gathered.
949 . Entity relationship diagrams
- An Entity Relationship Diagram is also referred to as an analysis ERD.
- ERD is to provide the development team with a picture of the different categories
- categorize data
950. Business process diagrams
- The process model illustrates all the parent and child processes that are performed by individuals within a company.
- The process model gives the development team an idea of how data moves within
- all