Data Analytics & Visualization All-in-One For Dummies
by Jack A. Hyman, Luca Massaron, Paul McFedries, John Paul Mueller, Lillian Pierson, Jonathan Reichental, Joseph Schmuller, Alan R. Simon, Allen G. Taylor
Chapter 5
Tuning Queries
IN THIS CHAPTER
Avoiding retrieving duplicate records
Managing multiple selection conditions
Saving resources with temporary tables
Filtering out groups that don’t meet a search condition
Working with indexes
Performance is almost always a top priority for any organizational database system. As the usage of the system goes up, if resources such as processor speed, cache memory, and hard disk storage do not go up proportionally, performance starts to suffer, and users start to complain. Clearly, one thing that a system administrator can do is increase the resources — install a faster processor, add more cache, buy more hard disks. These solutions may give the needed improvement and may even be necessary, but you should try a cheaper solution first: improving the efficiency of the queries that are loading down the system.
Generally, there are several different ways that you can obtain the information you want from a database; in other words, there are several ...