What is dangling tuple in SQL?

sql. A tuple with a foreign key value that does not appear in the referenced relation is said to be a dangling tuple.

What is dangling tuple problem in DBMS?

What is Dangling tuple problem? In DBMS if there is a tuple that does not participate in a natural join we called it as dangling tuple . It may gives indication consistency problem in the database.

What is meant by spurious tuples?

Spurious Tuples are those rows in a table, which occur as a result of joining two tables in wrong manner. They are extra tuples (rows) which might not be required.

What is a tuple in database?

(1) In a relational database, a tuple is one record (one row). Typically separated by commas, the values may be parameters for a function call or a set of data values for a database.

What is referential integrity in DBMS?

Referential integrity refers to the relationship between tables. Referential integrity is the logical dependency of a foreign key on a primary key. The integrity of a row that contains a foreign key depends on the integrity of the row that it references—the row that contains the matching primary key.

What is active database in DBMS?

Active Database is a database consisting of set of triggers. In such database, DBMS initially verifies whether the particular trigger specified in the statement that modifies the database) is activated or not, prior to executing the statement.

Why is spurious tuples generated in DBMS?

A spurious tuple is, basically, a record in a database that gets created when two tables are joined badly. In database-ese, spurious tuples are created when two tables are joined on attributes that are neither primary keys nor foreign keys.

What is lossless join in DBMS?

In database design, a lossless join decomposition is a decomposition of a relation into relations. such that a natural join of the two smaller relations yields back the original relation. This is central in removing redundancy safely from databases while preserving the original data.

What is tuple with example?

Tuple is a collection of values separated by comma and enclosed in parenthesis. Unlike lists, tuples are immutable. The immutability can be considered as the identifying feature of tuples. I will explain the features of tuples and operations on them with examples.

What is difference between fields and tuples?

A field is similar to a column in a database table. Each field has a specific name, type and value, as shown in the following figure. Tuples and fields function like rows and columns in a traditional database. A tuple can be seen as a kind of map in which fields can be put or removed.