A Logical database uses only a hierarchical structure of tables i.e.
Data is organized in a Tree-like Structure
and the data is stored as records that are connected to each other through edges (Links). Logical Database contains Open SQL statements which are used to read data from the database.
What describes the structure of a database?
The correct answer is
schema
. The schema describes the structure of the database.
Which term is used to describe the logical structure of a database?
A logical data model or logical schema
is a data model of a specific problem domain expressed independently of a particular database management product or storage technology (physical data model) but in terms of data structures such as relational tables and columns, object-oriented classes, or XML tags.
Which term refers to a description that defines the logical and physical structure of the database by identifying the tables the attributes in each table and the relationships between attributes and tables?
Schema
. A description that defines the logical and physical structure of the database by identifying the tables, the fields in each table, and the relation- ships between fields and tables.
Which of the following determines logical structure of the database?
A database model
is a type of data model that determines the logical structure of a database.
What is difference between physical and logical standby database?
Logical standby is different from physical standby:
Logical standby database does not have to match the schema structure of the source database
. Logical standby uses LogMiner techniques to transform the archived redo logs into native DML statements (insert, update, delete).
What is physical and logical database?
A
logical database must be able to access and identify all files within the storage system to operate correctly
, whereas a physical database manages a much smaller field of information. Sometimes, a physical database stores only a single file with one value or word in it.
What are the 3 types of schema?
2 Three Types of Schema Schema can be classified into three types:
linguistic schema, content schema and formal schema
(Carrell, 1984).
What is the good structure of a database?
A good database design is, therefore, one that:
Divides your information into subject-based tables to reduce redundant data
. Provides Access with the information it requires to join the information in the tables together as needed. Helps support and ensure the accuracy and integrity of your information.
What are the different types of database structures?
- single-file or flat file database.
- multi-file relational or structured database.
Which term best describes an attribute in a database table?
From the options given,
a column
is the best descriptor of an attribute in a database table. For example, a table of customer information might contain columns for Customer_ID, First_Name, Last_Name, Address, City, State, Zip, Phone.
What is an attribute in database?
In general, an attribute is
a characteristic
. In a database management system (DBMS), an attribute refers to a database component, such as a table. It also may refer to a database field. Attributes describe the instances in the column of a database.
Which term attribute refers to a table?
Answer: B. Attribute is a specific
domain
in the relation which has entries of all tuples. In the context of relational databases, a column is a set of data values, all of a single type, in a table. Columns define the data in a table, while rows populate data into the table.
How is primary key represented in ER diagram?
It is represented by a double rectangle symbol. It contains a Primary key represented by
the underline symbol
. … In a weak entity set, it is a combination of primary key and partial key of the strong entity set. In the ER diagram the relationship between two strong entity set shown by using a diamond symbol.
What is logical schema in DBMS?
A logical data model or logical schema is
a data model of a specific problem domain expressed independently of a particular database management product or storage technology
(physical data model) but in terms of data structures such as relational tables and columns, object-oriented classes, or XML tags.
What are five types of database models?
There are various types of database models like
network model, entity-relationship model, hierarchical model, object-oriented model and object model
. These all types of database models have different looks from each other and the operations performed on this type of database model are different from each other.
