Oracle Database

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Oracle Database 12c has new enhancements and additions in Recovery Manager (RMAN).  The Recovery Manager continues to enhance and extend the reliability, efficiency, and availability of Oracle Database Backup and Recovery. In this article series, I will be explaining the new features and how it will help Oracle community. In this article I will cover: SQL Interface Improvements SYSBACKUP Privilege… Continue Reading →

12c, All Things Oracle Full Articles, Database Administration, Oracle Database

What is cloning? Cloning is a process of copying an existing installation to a different server or location. Cloning is similar to an Oracle installation except Oracle universal installation performs the actions in a special mode called “clone mode”. Starting from 10g onwards, Oracle supports cloning and users can easily clone existing Oracle installations. The source and destination servers should… Continue Reading →

10g, 11g, All Things Oracle Full Articles, Database Administration, Database Development

It’s time to move away from the shape of an execution plan and turn our attention to some of the numerical information we get from the plan. In this article we’re going to look only at the predictions that the optimizer makes (explain plan), postponing any investigation of actual run-time figures (v$sql_plan_statistics_all) for future instalments. Getting Started As a reference… Continue Reading →

All Things Oracle Full Articles, Database Administration, Oracle Database

In Part 1, I described how data security is critical to the modern enterprise business world and the key role it plays, as well as some of Oracle 12c’s security features.  In Part 2, I am going to touch how to apply security controls in network, storage and backup levels. Also, a few selective Oracle database 12c new security features… Continue Reading →

12c, All Things Oracle Full Articles, Database Administration, Oracle Database

In the final part of this series I want to cover one last source of Parallel Execution Skew: Skew caused by Outer Joins. If you have Outer Joins where the majority of foreign key values is NULL, this can lead to the following symptoms: From a processing point of view for a parallel outer join, the NULL value in the foreign… Continue Reading →

10g, 11g, 12c, All Things Oracle Full Articles, Database Administration, Database Development, Oracle Database, Performance Tuning, Troubleshooting

Oracle Database 12c is designed for the cloud and introduces Multitenant Architecture with more than 500 new features. It enables customers to make more efficient use of their resources and reduce IT costs. What is Multitenant Architecture? Oracle 12c now introduces multitenant architecture featuring pluggable databases, which makes it easy to consolidate your databases on to the cloud, deliver high… Continue Reading →

12c, All Things Oracle Full Articles, Database Administration, Oracle Database

In this part of the series we will have a look at different approaches to how Parallel Execution Skew can be addressed via manual re-writes of an affected query. Let’s have a look at a couple of options. Approach 1: Mimic the new 12c skew aware feature Looking at the new 12c special skew aware distribution feature that I’ve introduced… Continue Reading →

10g, 11g, 12c, All Things Oracle Full Articles, Oracle Database, Performance Tuning, Troubleshooting

I’ve offered up “first child first, recursive descent” as a basic strategy for interpreting execution plans – but it’s not a perfect rule, and it can be easy to lose track of what’s going on even when the basic “first child first” is being obeyed. In this article we’ll be looking at a couple of examples where we will still… Continue Reading →

12c, All Things Oracle Full Articles, Database Administration, Oracle Database

Since Parallel Execution Skew is a common problem that can severely limit the scalability of Parallel Execution (see my previous article for a demonstration), Oracle has introduced a new feature in 12c that can address the problem automatically. That’s great, but unfortunately – at least in the initial 12c release – it only applies to a limited number of scenarios,… Continue Reading →

12c, All Things Oracle Full Articles, Oracle Database, Performance Tuning, Troubleshooting

In part 3 of this series we used a simple hash join to introduce the a simple guideline for reading execution plans – the “first child first, recursive descent” method. This allowed us to work out the order in which Oracle produced rowsources and (implicitly) the order in which it visited the different physical objects in the query. At the… Continue Reading →

All Things Oracle Full Articles, Oracle Database, Performance Tuning