BMGT 402 Lecture Notes - Lecture 3: Compound Key, Database Server, Subset

• School: University of Maryland
• Department: Business and Management
• Course: BMGT 402
• Professor: Woei- Jyh Lee

Document Summary

Bmgt402 lecture 3 chapter 3: database architectures continued, chapter 4: Components of a dbms: partitioned into several software components (or modules), each of which is assigned to a specific operation, the dbms interfaces with other software components, such as user queries and access methods, major components. Figure 3. 21: components of database manager: many smaller components within dm. A relation is a table with columns and rows: only applies to logical structure of the database, not the physical structure. An attribute is a named column of a relation. Domain is the set of allowable values for one or more attributes. A tuple is a row of a relation. Degree is the number of attributes in a relation: literally the number of columns. Cardinality is the number of tuples in a relation: literally the number of rows. Relational database is a collection of normalized relations with distinct relation names.