Information Modeling

By David Edmond

This PDF version of book covers Introduction (brief intro to Z and to SQL), Specific facts (relations and functions in Z), Sets (set extension, comprehension, power sets, product sets), Relations (database relations - Z style) , Introducing SQL, SQL retrieval (select from where), SQL modularization (group by, views), Facts and relations (conceptual schema modelling), Uncovering facts (brief methodology), Fact-based analysis (case-study), Entity-relationship modeling, Knowledge (predicate calculus, quantification), The knowledge base (intro to schemas in Z), From specification to implementation (specifying in Z, implementing in SQL), Database definition in SQL (create table, index, view), Database manipulation in SQL (insert, update, delete), Application programming, Case studies, and Refinement.

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Introduction to Databases for web developers

extropia.com

Types of Database

These days, when you talk about databases in the wild, you are primarily talking about two types:

• Analytical databases
• Operational databases.

Let's examine each type

Analytic databases (a.k.a. OLAP- On Line Analytical Processing) are primarily static, read-only databases which store archived, historical data used for analysis. For example, a company might store sales records over the last ten years in an analytic database and use that database to analyze marketing strategies in relationship to demographics.

On the web, you will often see analytic databases in the form of inventory catalogs such as the one shown on the previous page from Amazon.com. An inventory catalog analytical database usually holds descriptive information about all available products in the inventory.

Web pages are generated dynamically by querying the list of available products in the inventory against some search parameters. The dynamically-generated page will display the information about each item (such as title, author, ISBN) which is stored in the database.

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Building a Database-Driven Web Site Using PHP and MySQL

by Kevin Yank

On the Web today, content is king. After you've mastered HTML and learned a few neat tricks in JavaScript and Dynamic HTML, you can probably build a pretty impressive-looking Web site design. But then comes the time to fill that fancy page layout with some real information. Any site that successfully attracts repeat visitors has to have fresh and constantly updated content. In the world of traditional site building, that means HTML files--and lots of 'em.

The problem is that, more often than not, the people providing the content for a site are not the same people handling its design. Oftentimes, the content provider doesn't even know HTML. How, then, is the content to get from the provider onto the Web site? Not every company can afford to staff a full-time Webmaster, and most Webmasters have better things to do than copying Word files into HTML templates anyway........

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Data Transfer Strategies

Transferring data between XML documents and relational databases

by Ronald Bourret

In this paper we will discuss strategies for transferring data between XML documents and relational databases according to two mappings (a table-based mapping and an object-based mapping) commonly used to map DTDs to relational databases. Although the discussion largely focuses on the difference between using SAX- and DOM-based tools to transfer data, it also discusses a number of strategies for traversing both the XML and database hierarchies and the tradeoffs among them.

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Concurrency Control and Recovery in Database Systems

By Philip A. Bernstein, Vassos Hadzilacos and Nathan Goodman

For over 20 years, businesses have been moving their data processing activities on-line. Many businesses, such as airlines and banks, are no longer able to function when their on-line computer systems are down. Their on-line databases must be up-to-date and correct at all times.

In part, the requirement for correctness and reliability is the burden of the application programming staff. They write the application programs that perform the business’s basic functions: make a deposit or withdrawal, reserve a seat or purchase a ticket, buy or sell a security, etc. Each of these programs is designed and tested to perform its function correctly. However, even the most carefully implemented application program is vulnerable to certain errors that are beyond its control. These potential errors arise from two sources: concurrency and failures.

Multiprogramming is essential for attaining high performance. Its effect is to allow many programs to interleave their executions. That is, they execute concwrently. When such programs interleave their accesses to the database, they can interfere. Avoiding this interference is called the concurrency control problem.

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Concurrency Control and Recovery in Database Systems