Temporal Databases presents about What is temporal DB? Applications of temporal db; valid time temporal data model; time normalization; temporal query language; conceptual design and logical design and somethings else. | Temporal Databases VALID-TIME TEMPORAL DATA MODEL TIME NORMALIZATION TEMPORAL QUERY LANGUAGE CONCEPTUAL DESIGN AND LOGICAL DESIGN What is temporal DB? Temporal databases, encompass all DB applications that require some aspect of time when organizing their information. They exhibit the need for developing a set of unifying concepts for application developers to use. Temporal DB applications have been developed since the early days of database usage. However, in creating these applications, it was mainly left to the application developers to discover, design, program, and implement the temporal concepts. Applications of temporal db There are many examples of applications where some aspect of time is needed to maintain the information in a DB. Health care: patient histories need to be maintained Insurance: claims and accident histories are required Finance: stock price histories need to be maintained. Personnel management: salary and position history need to be maintained Banking: credit histories This chapter will introduce some of the concepts that have been developed to deal with the complexity of temporal database applications. Terminology Valid time. The valid time denotes when facts are true with respect to the real world. Transaction time. The transaction time of a database fact is the time when the fact is current in the database. Unlike valid time, transaction time may be associated with any database entity. Although time is a continuous value in the real world, for database application, time is usually discretized as timepoints on a timeline. Chronon. A chronon is the shortest duration of time supported by a temporal DBMS. It is a non-decomposable unit of time. 1. VALID-TIME TEMPORAL DATA MODEL Temporal database systems typically use relational databases, which provide well-defined data models and query languages. However, the relational model has two significant shortcomings regarding temporal data: 1. The relational model provides . | Temporal Databases VALID-TIME TEMPORAL DATA MODEL TIME NORMALIZATION TEMPORAL QUERY LANGUAGE CONCEPTUAL DESIGN AND LOGICAL DESIGN What is temporal DB? Temporal databases, encompass all DB applications that require some aspect of time when organizing their information. They exhibit the need for developing a set of unifying concepts for application developers to use. Temporal DB applications have been developed since the early days of database usage. However, in creating these applications, it was mainly left to the application developers to discover, design, program, and implement the temporal concepts. Applications of temporal db There are many examples of applications where some aspect of time is needed to maintain the information in a DB. Health care: patient histories need to be maintained Insurance: claims and accident histories are required Finance: stock price histories need to be maintained. Personnel management: salary and position history need to be maintained .
