Managing Time in Relational Databases: How to Design, Update and Query Temporal Data pptx

... brought on-line and assembled into a single database instance, and data marts are the form that transaction logs took when brought on- line and assembled into their database instances. The former is history ... book describes how current relational technology can be adapted to handle temporal data, and indeed to handle data along two orthogonal temporal dimensions. Bu...

Ngày tải lên: 27/06/2014, 06:20

... Pipeline Datasets The final objective of this book is to describe how to bring pending transactions into the production tables that are their targets, and how to retain posted transactions in those same ... IN RELATIONAL DATABASES How to Design, Update and Query Temporal Data TOM JOHNSTON RANDALL WEIS AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD...

Ngày tải lên: 24/12/2013, 02:16

... files took when brought on-line and assembled into a single database instance, and data marts are the form that transaction logs took when brought on- line and assembled into their database instances. ... possible, and computer scientists are working on it. We are, too. Our work has led to this book, and to the software we are developing to implement its concepts. Managing...

Ngày tải lên: 24/12/2013, 02:16

... book describes how current relational technology can be adapted to handle temporal data, and indeed to handle data along two orthogonal temporal dimensions. But in the process of doing so, it also shows how ... the point in time we are interested in. But the defining feature of reconstructable methods is not the movement of data from off-line to on-line storage....

Ngày tải lên: 24/12/2013, 02:16

... lacking a standard for the PERIOD datatype, we will continue the practice of defining periods of time in terms of their begin and end points in time. Chapter 3 THE ORIGINS OF ASSERTED VERSIONING: ... represented in an asserted version 48 Part 2 AN INTRODUCTION TO ASSERTED VERSIONING which contains data destined for production tables are inflow pipeline datasets. Pipeline datas...

Ngày tải lên: 24/12/2013, 02:16

... a bi -temporal row can be inserted into a table proactively in valid time, but can never be inserted into a table proactively in transaction time. Asserted Versioning, as we have already pointed ... in time, but not prior to Now(). In Chapter 15, we will describe certain indexing strategies that will improve performance using today’s DBMS index designs. Temporal Extensions t...

Ngày tải lên: 24/12/2013, 02:16

... rows in non- temporal tables. They start and end at the same points in time. But whereas updates to a row in a non -temporal table simply overwrite the old data, the corresponding updates in an ... of entity integrity and referential integrity. Temporal entity integrity is entity integrity applied to temporal tables. But we need to understand what “entity integrity...

Ngày tải lên: 24/12/2013, 02:16

... the truth. Temporal Integrity Constraints The three integrity constraints in relational theory are entity integrity, referential integrity and domain integrity. Entity integ- rity insures that ... changes to data. They are changes to types of data, indeed to datatypes. Domain changes are one form of what computer scientists call schema evolution. Adding or removing tables, al...

Ngày tải lên: 24/12/2013, 02:16

... point in time. With non -temporal tables, we assert a row to be true by the act of inserting it into its table, and we cease to assert that it is true by deleting it from its table. With non -temporal ... represent. As we enter into a series of chapters which will describe our method of temporal data management in great detail, we will sometimes Managing Time in Relat...

Ngày tải lên: 24/12/2013, 02:16

... integrity and temporal referential integrity on those tables. If ERwin is used as the data modeling tool, then a set of ERwin 162 Part 3 DESIGNING, MAINTAINING AND QUERYING ASSERTED VERSION DATABASES Note ... against non -temporal tables insert, update or delete individual rows representing objects, transactions against asserted version tables insert into a period of time, update...

Ngày tải lên: 21/01/2014, 08:20