Building the Data Warehouse

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The ability to measure response time in the DSS environment is the first step toward being able to manage it. For this reason alone, monitoring DSS activity is an important procedure.


One of the issues of response time measurement in the DSS environment is the question, “What is being measured?” In an OLTP environment, it is clear what is being measured. A request is sent, serviced, and returned to the end user. In the OLTP environment the measurement of response time is from the moment of submission to the moment of return. But the DSS data warehouse environment varies from the OLTP environment in that there is no clear time for measuring the return of data. In the DSS data warehouse environment often a lot of data is returned as a result of a query. Some of the data is returned at one moment, and other data is returned later. Defining the moment of return of data for the data warehouse environment is no easy matter. One interpretation is the moment of the first return of data; another interpretation is the last return of data. And there are many other possibilities for the measurement of response time; the DSS data warehouse activity monitor must be able to provide many different interpretations.


One of the fundamental issues of using a monitor on the data warehouse environment is where to do the monitoring. One place the monitoring can be done is at the end-user terminal, which is convenient many machine cycles are free here and the impact on systemwide performance is minimal. To monitor the system at the end-user terminal level implies that each terminal that will be monitored will require its own administration. In a world where there are as

Скачать в pdf «Building the Data Warehouse»