Q. Which of the following is not characteristic of a relational database model?
Below are some of the characteristics of relational databases and the relational model.
- tables
- treelike structure
- complex logical relationships
- records
- None of the above
A relational database is a digital database based on the relational model of data, as proposed by E. F. Codd in 1970. A software system used to maintain relational databases is a relational database management system (RDBMS). Virtually all relational database systems use SQL (Structured Query Language) for querying and maintaining the database.
- The use of keys
Each row of data in a table is identified by a unique "key", called the primary key
- Avoiding data redundancy
- Constraining the input
Using a relational database you can specify what sort of data a database column is allowed to contain. You can create fields that contain numbers, decimal numbers, small texts, large texts, dates, etc.
- Maintaining data integrity
- Rights
Most relational database systems offer a rights structure with which rights can be assigned to different users. Some of the operations that can be allowed or disallowed to a user are SELECT, INSERT, DELETE, ALTER, CREATE, etc. These rights correspond to the operations that can be performed using the Structured Query Language (SQL).
- Structured Query Language (SQL)
- Portability
The relational model is a standard. By adhering to the rules of the relational model you ensure that your data can be transferred between relational database systems relatively easily.
Q. Which of the following is a characteristic of a relational database system?
- All data within the system are shared by all users to facilitate integration.
- Database processing follows explicit links that are contained within the records.
- User views limit access to the database.
- Transaction processing and data warehousing systems share a common database
Answer: Database processing follows explicit links that are contained within the records.
The database should follow the links which are having the information in the form of records. Through records the data can be shared to users in the relational database systems.
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