by Courant Institute of Mathematical Sciences, New York University in New York .
Written in English
|Statement||By Alexander Tuzhilin, Zvi M. Kedem.|
|Contributions||Kedem, Zvi M.|
|The Physical Object|
|Number of Pages||25|
In this paper, we present a language for querying temporal evolutions of databases. The underlying time model consists of sequences of database states. The general structure of the language is similar to traditional query calculi. Thus temporal queries can be specified in a descriptive logic-oriented : Klaus Hülsmann. we use it as our target database query language when translating temporal logic. A valid-time relation is a where tuples are implicitly timestamped with periods3. Example 5. Table 2 contains a concrete TSQLZ relation representing the abstract temporal database shown in Table 1. historical databases and temporal logic is to restrict the functionality of US logic languages to include only those operators and constructs which arc equivalent to those in SOIIIC temporal cxtcnsion of the rclntional model anti algchr;~. in a manner similar to Datalog for the standard. Data analysis: SQL Server allows you to perform complex time travel querying very easily, using the FOR SYSTEM_TIME clause and hiding all complexity of matching current and historical data from you. The power of temporal querying becomes apparent in combination with views, especially in scenarios when you need to query complex database models including multiple Temporal Tables .
Abstract. Queries over temporal databases involve references to time. We study differences between two approaches of including such references into a first-order query language (e.g., relational calculus): explicit (using typed variables and quantifiers) vs. implicit (using a Cited by: INTRODUCTION TO TEMPORAL DATABASE RESEARCH 3 Next, the transaction time of a database fact is the time when the fact is cur-rent in the database. Unlike valid time, transaction time may be associated with any database entity, not only with facts. For example, transaction time may be associ-File Size: KB. Temporal and Real-Time Databases: A Survey Gultekin Ozsoyoilu and Richard T. Snodgrass Abstract-A temporal database contains time-varying data. In a real-time database transactions have deadlines or timing constraints. In this paper we review the substantial research in these two previ- . We formalize our notion of a query: Deﬁnition 7. Given a database scheme S, let DB(S) be all possible database instances over domain D. Deﬁnition 8. If Sis a database scheme, then dom(S) is its domain. Deﬁnition 9. A database query is a question to the database that is an-swered by a relation of some arity kover the domain of the database File Size: KB.
Abstract. We establish an exact correspondence between temporal logic and a subset of TSQL2, a consensus temporal extension of SQL The translation from temporal logic to TSQL2 developed here enables a user to write high-level queries which can be evaluated against a space-efficient representation of the by: Areas of activity include, but are certainly not restricted to: Pure Temporal Logic, e. g. temporal systems, proof theory, model theory, expressiveness and complexity issues, algebraic properties Author: Yde Venema. Focusing on temporal databases, different granularities and indeterminacy have to be considered in expressing valid time, i.e., the time at which the information is true in the modeled reality. To analyze the performance of temporal queries on databases using various access methods, we propose a model that takes a temporal query and a database Author: Richard Snodgrass.