Database Management 5 Flashcards
(sometimes called a table) as a two-dimensional structure composed of intersecting rows and columns. Each row in a relation is called a tuple. Each column represents an attribute. The relational model also describes a precise set of data manipulation constructs based on advanced mathematical concepts.
Relation
performs the same basic functions provided by the hierarchical and network DBMS systems, in addition to a host of other functions that make the relational data model easier to understand and implement.
relational database management system (RDBMS)
is a representation of the relational database’s entities, the attributes within those entities, and the relationships between those entities.
relational diagram
both data and its relationships are contained in a single structure known as an object. In turn, the OODM is the basis for the object-oriented database management system (OODBMS).
object-oriented data model (OODM)
The ERDM adds many of the OO model’s features within the inherently simpler relational database structure. The ERDM gave birth to a new generation of relational databases that support OO features such as objects (encapsulated data and methods), extensible data types based on classes, and inheritance.
extended relational data model (ERDM)
refers to a movement to find new and better ways to manage large amounts of web and sensor-generated data and derive business insight from it, while simultaneously providing high performance and scalability at a reasonable cost.
Big Data
is based on a structure composed of two data elements: a key and a value, in which every key has a corresponding value or set of values. The key-value data model is also referred to as the attribute-value or associative data model.
The key-value data model
intersection data describes the relationship between the two entities.
primary key (PK) is an attribute or combination of attributes that uniquely identifies any given row.
key consists of one or more attributes that determine other attributes.
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is the state in which knowing the value of one attribute makes it possible to determine the value of another.
Determination
functional dependence, which means that the value of one or more attributes determines the value of one or more other attributes.
In this functional dependency, the attribute whose value determines another is called the determinant or the key. The attribute whose value is determined by the other attribute is called the dependent.
full functional dependence, is used to refer to functional dependencies in which the entire collection of attributes in the determinant is necessary for the relationship.
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