Database Development

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The Oracle GoldenGate software package delivers low-impact, real-time data integration and transactional data replication across heterogeneous systems for continuous availability, zero-downtime migration, and business intelligence. Oracle GoldenGate 12c empowers organizations to capture, route, transform, and deliver transactional data between heterogeneous databases in real time with minimal overhead.  In 12c, it is now available with new features for all major operating… Continue Reading →

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

Sometimes the best way to see the familiar is to go far from it – Wisdom of the desert In previous articles (collections I and collections II) I described the different types of collections, their possibilities and their limits. One of the limits was the possibility to use an Associative Array in a SQL statement. If you are building your… Continue Reading →

12c, All Things Oracle Full Articles, Database Development, Oracle Database, PL/SQL

Designing an index is not done through “trial and error”. This kind of strategy seems to doom many engineered indexes to imprecision, explosion, and locking issues. Designing a precise index very often tends to be a “kill two birds with one stone” strategy.  In this article I am going to show you how to design a single index with which… Continue Reading →

All Things Oracle Full Articles, Database Administration, Database Development

In part 9 we saw an example of a simple nested loop join where the basic method for interpreting the numbers in an execution plan started to break down because the arithmetic used by the optimizer to calculate the resource costs for the plan wasn’t consistent with the visual representation of the mechanics of the run-time path. In this instalment we’re… Continue Reading →

All Things Oracle Full Articles, Database Administration, Database Development

In part 8 we looked at a very simple execution plan involving a hash join; but that example was too simple to give us the full flavour of the arithmetic involved in Oracle’s predictions because every operation executed just once. We need to see some plans where each execution of a parent operation could requires multiple executions of its child… Continue Reading →

All Things Oracle Full Articles, Database Administration, Database Development

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

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

A wise man once said, I know one thing: that I know nothing. If you’ve followed this series from the very beginning I am hoping that you’ve gone from knowing absolutely nothing about Oracle database programming to this point where you know the foundations, know how the parts fit together – basically, know enough to know that there’s a whole… Continue Reading →

All Things Oracle Full Articles, Database Development

In part 5 of this series we examined a couple of examples where you had to handle the “first child first” rule with a little care. In part 6 we continue this exploration to look at a general principle – the “pushed subquery” – where the “first child first” could lead you to the wrong conclusion. Access or Filter If… Continue Reading →

All Things Oracle Full Articles, Database Administration, Database Development

A wise man once said: start at the beginning and go on till you come to the end: then stop. We’ve done things a little differently; all this time we’ve been talking about examining and manipulating the data in our tables, but we have never paused to consider where these tables come from, or discuss how they are created.  Time… Continue Reading →

All Things Oracle Full Articles, Database Development