9/21 Reading Notes

"Database"
-integrated collection of related records or files consolidated into a coomon pool that provides data for applications.
Can be classified by types of documents-bibliographic, full-text, numeric, images.

Data in a database is organized by a database model. Most common:relational model. Also:hierarchial model,network model.

Architecture
On-line Transaction Processing Systems
Document-oriented, XML,knowledge bases, frame databases
Not all databases need a database schema.
Rise of general purpose databases

Non-relational:
Object database managment system-stores language objects natively without using a separate data definition language w/o using a separate storage schema.

Database Management Systems:
DBMS-software that organizes the storage of data. Characterized by type of database model they support.

Relational Database Management System (RDBMS)
Information content of database represented one way.
ODBMS differs in that it sores explicit pointers between related tables.

RDBMS components:
Interface drivers
SQL Engine
Transaction Engine
Relational Engine
Storage Engine

ODMS components:
Language Drivers
Query Engine
Transaction Engines
Storage Engines

Types of DBMS packages
Database Development
"" Interrogation
"" Maintenance
Application Development

(Operational database) Subject-area databases
Customer databases
Personal databases
Inventory databases

Analytical database-stores data and information extracted from selected operational and external databases.

Data warehouse-stores data from current and previous years that has been extracted from the various operational databases of an org.

Distributed database-local work groups and departments at regional offices.

End-user database-data files developed by end-users at their workstations.

External database-privately owned, cost.
Other types: Hypermedia, navigational,in-memory,document-oriented databses, real-time

Models
Post-relational database models
Object database models

Indexing-allows a set of table rows matching criterion to be quickly located.
Locking-how a database handles multiple operations.
API-retrieves info stored.

"Introduction to Metadata"
Metadata-data about data. All information structures have content, context and structure.
Library metadata includes indexes, abstracts, bibiliographic records.
Archival and manuscript metadata- accession records, finding aids, cataloging records

Rise of user generated metadata
Pros, data created to meet specific needs.
Cons, quality control, trustworthiness

"An Overview of the Dublin Core Data Model"
DCMI-effort to create interdisciplinary agreement for discovery -oriented description of resources in an electronic environment.