Without the ability to view, manipulate, and update data stored on the computer, the most sophisticated storage infrastructure is meaningless. Our last storage fundamental covers the methods and types of organizational models used to facilitate the productive use of stored data. Data organizational models and methods are part of the entire storage infrastructure. Their proximity to other elements within the infrastructure indicates that structures, such as file systems and databases, are the critical connectivity between application and end user . Data is stored for many different reasons and accessed in as many ways to support a rapidly changing business environment. The knowledge, awareness, and insight to the diversity of data organizational models is as important and critical as that of storage systems and connectivity options.
Data in computer systems is organized by creating databases. Databases are defined as a collection of interrelated material stored in an environment that is both convenient and efficient to use in retrieving information. This is done through a combination of file systems, database management systems (DBMS), and applications. Combined with an effective storage system, the database can offer an environment where data can not only be stored and updated on a reliable basis but also be accessed in multiple ways.
Underlying the DBMS is the file system that works as a component of the operating system. The file system functions as the operating systems ability to organize and retrieve the physical data that exists on attached storage media and within memory devices. File systems deal with the physical aspects of storage media, the data locations, as they are stored within the media segments, and the status of the data within. They also provide the first level of transparency to the user or owner of the data.
Database management systems (DBMS) provide methods for defining the data, enhanced access to data generally through some type of enhanced indexing system, and functions for maintaining the data structures as well as the data itself. Defining and accessing the data through a DBMS, users can additionally perform calculations and logical functions on the stored data, and present the data in enhanced views (usually tabular reports that include graphics and charts ).
Business applications take advantage of the file system and DBMS functions by using their transparent data retrieval and dealing directly with the data without having to understand or know the underlying operations of the DBMS or a native file system. As we indicated in Chapter 1, most application designers and programmers can use these high-level functions without regard to the underlying hardware and software infrastructure. Others can be locked into specific DBMSs and file systems that have become standardized within their data centers.