Week 4 Readings

1.) Wikipedia - Database Article

This article provided an overview of databases and their features.

Databases can be either row or column orientated. Database Management Systems is the software that organizes the storage of the data. It controls the creation, maintenance, and use of the data. Most DBMS's are relational and have five components: the interface drivers, SQL Engine, Transactions Engine, Relational Engine, and Storage Engine.

There are many different types of databases, many of them highly specialized. It seemed that an operational database is the one an average person would use on a day to day basis. Databases make use of indexing, which can increase the speed of the database. Indexing allows a set of tables and rows matching a certain criteria to be located quickly. Indexing takes up a lot of storage room, and must be updated consistently, which takes time.

Like all things dealing with computers, security is a big issue for databases. They have three main things to enforce security. 1. Access Control - who can and cannot access the database, and what they can do to it. 2. Auditing Logs - What has been done, when, and by whom. 3. Encryption - data is encoded and then deciphered

Locking is how databases handle multiple, concurrent operations. Only one process at a time can modify the same data. Databases can handle multiple locks at the same time.

Overall, this article was a good general overview of databases.

2.) Gilliland - Introduction to Metadata

Metadata is "data about data" - it is widely used but understood in many different ways by different people. All information objects have three features which can be reflected through metadata. 1. Content - relates to what the object contains or is about - intrinsic to an information object. 2. Context - indicates who, what, where, why, how of an objects creation. 3. Structure - formal set of associations within objects.

Libraries and museums use metada - the information they create to arrange, describe, track, and enhance access to the information. Their goal first and foremost is to provide intellectual and physical access to materials. Larege part of archives and museums use of metadata is on context - preserving context.

The structure of metada is important - it can provide visual cues to researchers. The more structure you have the more searching and manipulating you can do. Metadata is also used in digitization, primarily as descriptors of the context.

The primary functions of metadata are: Creation and reuse - either created digitally or converted into digital format, Administrative/Descriptive - metadata should be added to descriptors especially dependign upon the intended use of the object, Organization and Description - describing and organizign objects in a collection, Validation - prove the authenticity and trustworthiness, Disposition - metadata is key component in documenting disposition of objects.

3.) Miller - Dublin Core.

This article was about DCMI. This article was pretty basic and didn't really say all that much, yet at the same time was very confusing. I'm fairly good with computers and know a lot about them, yet I didn't really have any idea what this article was saying - or more importantly what it was trying to convey to the reader. It basically just listed the main aspects of DCMI in very technical terms and nothing else.

What I think the main points of it were that they realized there would never be a "true" set of semantics so in making DCMI they had to make the ability to mix semantics necessary. You must refine general semantics to say something more specific. The ability to specify a particular encoding system is critical. Things may be written and said in different ways, but they need to be written in the same code.

Standardds are necessary for DCMI to work on a global level. The standards must be as precise as possible.

Overall, I really didn't understand the point of this article (not the point of why we had to read it - I understand why we had to read about DCMI - the actual main point of the article. And even though I have a fairly good understanding of computers and understood most of the technical jargon in teh article it was still confusing. I'm sure most people were probably even more confused than I as. Oh, well - it will be a good thing to learn in class this week at least.