Many Oracle professional do not realize the important of having good statistics for the Oracle cost-based SQL optimizer (CBO). The CBO has received a "bum-rap" from some Oracle professionals who wonder why the CBO is generating sub-optimal execution plans for their SQL statements.
Oracle databases have many types of auditing features. In mandatory auditing, certain actions are always audited, regardless of the other audit options or parameters. Database activities, such as system startup and shutdown, are always recorded.
SQL tuning is one of the challenging tasks faced by DBAs and developers. It is an interesting and creative, but at the same time, daunting task. Manual tuning of SQL statements requires a high level of expertise and experience to understand and design suitable access paths to yield better response times. It is also a time consuming process. Other challenges include periodic collection of statistics and an ever-changing workload. And in a typical application, there are just too many SQL statements to tune.
This article tries to demystify HTTP, "servlet", "web server", "application server", "servlet container" and gives the fundamentals of the Java Servlet API (that comes with the J2EE SDK).
This article focuses on the new features aimed at database management. Self-management, or easy management, has been the key word for Oracle 10g. The main areas of enhancements are:
- Self-Managing Database
- Simplified Configuration of Shared Servers
- Transaction Manageability
- Simplified Statistics Collection
- Extended Support for FGA (Fine Grain Audit)
- Response File Creation during database install
One of the most important responsibilities of an Oracle Database Administrator or Performance Analyst, when it comes to performance diagnostics, is to determine how users access the database. This article is an attempt to show the different ways one can activate tracing of an Oracle session for performance diagnostics. While the Oracle documentation mentions some of the methods, it doesn't cover them all. This article consolidates many methods of tracing an Oracle session, some of which are well documented, as well as methods that are undocumented and reserved.
Is there any limit to the speed of Oracle? With Oracle announcing a new record one million transactions per minute, many believe that there is nothing that Oracle cannot do.
However, what if we have a requirement for a system that must accept high-volume data loads into a single table:
- 500,000 rows per second
- 50 megabytes per second
Is this possible? Using the right tricks you can make Oracle load data at unbelievable speed. However, special knowledge and tricks are required.
If you write Java Server Pages, this article tries to bring together the pieces you need to know to write 'presentation logic'. This article is about custom tags, how to develop them and how to make maximum use of them. This article is also about tag libraries that come with Struts. What is covered is: what is a tag; what is a 'custom' tag; how you can build one; how they make life easier; and how Struts comes with tag libraries for developers to indulge.
While all SQL tuning professionals advocate tuning each individual SQL statement to reduce logical I/O, there are many cases where you do not have the luxury of tuning each-and-every SQL statement in an application. In these cases, the best you can hope to do is adjust the global optimizer parameters to optimizer as many SQL statements as possible.
by Nidhi Jain
Shared memory and semaphores are two important resources for an Oracle instance on Unix. An instance cannot start if it is unable to allocate what it needs.