Often when I have a 10046 trace file, especially when looking at I/O issues, I want a histogram of I/O response time. To get I/O response time I’ve hacked out incomple awk scripts from time to time, (more...)
Test data management is difficult, time consuming and expensive leading to incorrect implementation of test data management and significant losses in revenue from high QA costs to bugs in production. Fortunately there is a solution that alleviates the majority of the huge resource, time and planning of conventional test data management and that new technology is called data virtualization.
Dependable QA testing requires that code be tested on data that represents the data (more...)
Disjunction (logical OR) is known to cause various performance problems, from extreme parse times (e.g. here) to sub-optimal plans. A common solution to such problems is getting rid of OR’s by “OR expansion” (i.e. rewrite via UNION ALL), although it doesn’t work in 100% cases. In this post, I will consider an example of an OR problem that can be solved differently.
If you have had interesting experiences with SQL or PL/SQL in your career, here’s your opportunity to share them on stage, on camera, or in print. Send your stories to email@example.com and we’ll forward them to the SQL evangelists team headed up by Steven Feuerstein. You may be selected to tell your stories on stage at the YesSQL! presentation at the winter conference next Tuesday or your stories may be recorded on camera or (more...)
When advising customers on ADF projects, I often find development environments where many or all developers are working against the same database. That introduces a hard dependency between different parts of the project – if one developer deploys a defective PL/SQL package to the database, nobody else can run the application.
This approach made sense back when hardware was expensive and databases had to be managed by high priests in glass-walled, climate-controlled rooms. Today, you (more...)
Delphix is now available for 30 day trial direct download ! ( if you would like a longer version please contact me at firstname.lastname@example.org year trials and even indefinite trials potential possible for partners, bloggers, Oracle Aces etc)
Just got to the
Delphix home page delphix.com and click the “Free Trial”
I’m sitting here watching the import of a moderately sized database via transportable tablespaces. You know…the thing you use when a full export / import would be too slow, and this is meant to be … well…fast.
And fast it is.. until it reaches the following step:
Processing object type TRANSPORTABLE_EXPORT/TABLE_STATISTICS
Now understandably, there’s plenty of stats to import, so its fair that it should take a little while. But a quick look (more...)
Data virtualization solutions also known as Copy Data Management (CDM), Copy Data Virtualization (CDV) and Data Virtualization Appliances (DVA) are rising rapidly as over 100 of the Fortune 500 have adopted data virtualization solutions between 2010 and end of 2014. Adoption is hardly surprising given that data virtualization reduces the time to provision copies of large data sets from days down to minutes and eliminates most of the space required (more...)
We had an interesting issue on 18.104.22.168, where users were reporting very slow performance on queries to external tables. When I tried to replicate the problem, everything seemed just fine, so I initially reported back the familiar "Well, it works on my PC" :-) [Just kidding]
Anyway, connecting by proxy to one of their accounts, did reveal the error, which suggested something to do with privileges. A sql trace revealed that (more...)
Flashback feature of Oracle database has been of interest to me since its inception in 9i. Thank you OTech Magazine for publishing my article on Flashback in the winter edition. Read the article here. There are several excellent articles in this edition of the Magazine. More than 100 pages of tech content. Don’t miss!! Merry Christmas! […]
Innovation in Managing the Chaos of Everyday Project Management discusses our strategy for leveraging the content management and collaboration features of Oracle WebCenter to enable project-centric organizations to build and deploy a project management portal. This solution was designed especially for groups like E & C firms and (more...)
NoSQL and Big Data are “disruptive innovations” in the sense used by Harvard professor Clayton M. Christensen. In The Innovator’s Dilemma: When New Technologies Cause Great Firms to Fail, Christensen defines disruptive innovations and explains how they eventually lead to the failure of the established players who ignored them:
“Generally, disruptive innovations were technologically (more...)
This article is about the importance of appropriately simplistic architectures. I frequently get involved with the creation of full-stack architectures—in particular the architecture of the database platform. There are some golden rules when designing such systems, but one of the most important ones is to keep the design as simple as possible. This isn’t a performance enhancement; this is an availability enhancement. Complexity, after all, is the enemy of availability.