so planning how much disk storage will be required and monitoring available disk space are key DBA responsibilities. Watching growth trends are important so that the DBA can advise management on long-term capacity plans. All notes and concepts are directed to OLTP relational databases.
SQL710 –Database Administration Using SQL Server Robert Stewart –[email protected]Page | 9 Updated: March 17, 2019 Performance monitoring and tuningThe DBA is responsible for monitoring the database server on a regular basis to identify bottlenecks (parts of the system that are slowing down processing) and remedy them. Tuning a database server is done on multiple levels. The capacity of the server hardware and the way the operating system is configured can become limiting factors, as can the database software configuration. The way the database is physically laid out on the disk drives and the types of indexing chosen also have an effect. The way queries against the database are coded can dramatically change how fast results are returned. A DBA needs to understand which monitoring tools are available at each of these levels and how to use them to tune the system. Proactive tuning is an attitude of designing performance into an application from the start, rather than waiting for problems to occur and fixing them. It requires working closely with developers of applications that run against the database to make sure that best practices are followed so good performance will result. TroubleshootingWhen things do go wrong with the database server, the DBA needs to know how to quickly ascertain the problem and to correct it without losing data or making the situation worse. High availabilityWith the advent of the Internet, many databases that could have been available only during the day are now required to be available 24 hours a day, 7 days a week. Web sites have changed from static, pre-defined content to dynamically created content, using a database to create the page layout at the time a page is requested. If the Web site is available 24x7, so must the underlying database. Managing a database in this environment requires an understanding of which types of maintenance operations can be done online (with the database available to users) and which must be scheduled for a maintenance "window" when the database may be shut down. It also requires planning for redundant hardware and/or software components, so that when one fails, others will keep the total system available to its users. Techniques like online backups, clustering, replication, and standby databases are all tools the DBA can use to ensure higher availability. Data Extraction, Transformation, and Loading (ETL or DTS)In data warehouse environments, a key task is efficiently loading the data warehouse or data mart with large volumes of data extracted from multiple existing production systems. Often these production systems have different formats than the standardized definitions in the data warehouse, so data must be transformed (or "cleansed") before loading. Extracting the data may or may not be the DBA's