Beginning Database Design- P6 doc

... Anomalies The intention of relational database theory is to eliminate anomalies from occurring in a database. Anomalies can potentially occur during changes to a database. An anomaly is a bad thing ... commercial relational database implementations do not go beyond the implementation of 3NF. This is often true of OLTP databases and nearly always true in properly designed data warehouse...

Ngày tải lên: 03/07/2014, 01:20

... for you. 06_574906 ch02.qxd 10/28/05 11:36 PM Page 23 databases. The OLTP database is the source database because the OLTP database is the database where all the transactional information in the ... differences between a database, a database model, and an application ❑ The hierarchical and network database models ❑ The relational database model ❑ The object and object-relationa...

Ngày tải lên: 03/07/2014, 01:20

... within relational databases that some database engines allow and some do not. It is important to know that specialized objects exist as options for expansion to a relational database model, as ... relationships Keys are used to identify and ultimately retrieve records from a database at a later date. Understanding Keys Relational databases use the terms index and key to indicate simila...

Ngày tải lên: 03/07/2014, 01:20

... databases, surrogate keys are possibly more important in terms of gluing together different data, even from different databases, perhaps even different database engines. Sometimes different databases ... data warehouse database simply cannot cope using a standard OLTP database relational database model. Something else is needed for a data warehouse. 173 Understanding Data Warehouse D...

Ngày tải lên: 03/07/2014, 01:20

... usually dependent on the database model. Analysis is planning. It is doubly important to plan for a database model. The reason is that the database model forms the basis of all database- driven applications, ... better a database model and product will ultimately be produced. Some database modeling and design tools allow generation of table scripts into different database engine...

Ngày tải lên: 03/07/2014, 01:20

... go overboard with normalization for an OLTP database model. ❑ Don’t be afraid to denormalize, even in an OLTP database model. ❑ Generally, an OLTP database model is normalized and a data warehouse ... each database model is usually secondary, and usually as a result of going too far initially, in the opposite direction. ❑ An OLTP database model should be normalized and a data wareho...

Ngày tải lên: 03/07/2014, 01:20

... online auction house data warehouse database model. These field refined field changes are all duplicated from the OLTP database model, to the database warehouse database model. Field refinements ... Design 17_574906 ch11.qxd 10/28/05 11:38 PM Page 323 ❑ XML Documents— Some databases allow structured storage of XML documents where the XML Document Object Model (DOM) is actively availab...

Ngày tải lên: 03/07/2014, 01:20

... relational database model is very good. Object-relational database model —The object-relational database model includes minimal aspects of the object database model into the relational database ... from a primary or master database, out to a number of other copies of the master database. Those copies can be fully dependent slave databases, or even other master databases, capable o...

Ngày tải lên: 03/07/2014, 01:20

... intra-document parent-child edges. So we actually consider only the much more compact document graph (introduced in Subsection 1.2) in the partitioning algorithm. The node weight of a document ... assess our index with respect to document size and frac- tion of links, we used the XMach benchmark suite [5] to generate a collection of synthetic documents. A document had about 165 elements ... t...

Ngày tải lên: 14/12/2013, 15:16

Ngày tải lên: 23/01/2014, 06:20