Conn. Developers need to carefully document and standardize such definitions as data elements and records, as well as document and manage changes to software. Making changes to these applications is difficult. When we want to switch applications, we have to yank out our entire interface and put in another one. Another widely used approach is data-level integration, which allows different applications to access a common data set, primarily for decision support. Our data warehouse lets us analyze data from many different operational systems at once and does so in a fashion that allows us to easily look at the data in many different ways.
Organizations can use database gateways, which provide real-time access to data for ad hoc queries.
Or they can use data warehousing products that transform data from different operational systems into a common format and move the data to a central place. Data warehousing tools offer the added advantage of giving users and applications access to large amounts of data. More than 50 percent of companies now have 500 or more gigabytes of information. A possible disadvantage is that data warehousing tools currently operate in batch mode, though new products are beginning to appear that will enable companies to perform more frequent updates. They bypass application-level business logic designed to manage the data.