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ORA-01719 is partially relaxed

You most likely have seen this error before: ORA-01719: outer join operator (+) not allowed in operand of OR or IN Cause: An outer join appears in an or clause. Action: If A and B are predicates, to get the effect of (A(+) or B), try (select where (A(+) and not B)) union all (select [...]

This Is A VERY Boring Blog!

I’ve been stranded in Europe for 4 days and the situation persists!  Needless to say I haven’t been thinking that much about blogging I do have a post nearly ready to go about booting 4s48c Opteron 6100 systems with _enable_NUMA_support set to TRUE. There are some caveats, and some very significant benefits as well. I’ll [...]

5th Planboard DBA Symposium: Registration now open

On June 8 Planboard will run her 5th Dutch DBA Symposium and the registration is now open. This “for Dutch DBA’s, by Dutch DBA’s” symposium has become the place to be for the serious DBA who wants to share his or her knowledge with other DBA’s in an open environment with plenty of networking time […]

The Core Performance Fundamentals Of Oracle Data Warehousing – Parallel Execution

[back to Introduction] Leveraging Oracle’s Parallel Execution (PX) in your Oracle data warehouse is probably the most important feature/technology one can use to speed up operations on large data sets.  PX is not, however, “go fast” magic pixi dust for any old operation (if thats what you think, you probably don’t understand the parallel computing paradigm). With Oracle PX, a large task is broken up into smaller parts, sub-tasks if you will, and each sub-task is then worked on in parallel.  The goal of Oracle PX: divide and conquer.  This allows a significant amount of hardware resources to be engaged in solving a single problem and is what allows the Oracle database to scale up and out when working with large data sets. I though I’d touch on some basics and add my observations but this is by far not an exhaustive write up on Oracle’s Parallel Execution.  There is an entire chapter in the Oracle Database documentation on PX as well as several white papers.  I’ve listed all these in the Resources section at the bottom of this post.  Read them, but as always, feel free to post questions/comments here.  Discussion adds great value. A Basic Example of Parallel Execution [...]

When column name matters

There’s a thread on the OTN forum with a case of amusing behavior of the JDBC driver: it fails to detect properly all bind variables in an SQL statement referencing column named NORDER. WTF?! PS. 1) Oracle’s SSO is actually Multi Sign-On because I have two accounts (one for OTN forums and one for [...]

NL join (ordered)

Some time ago there was a thread on the forum where user has asked the never-ending question “why CBO is doing this?”. The problem was a simple count(*) of parent-child tables join with no FK constraint was executed in very strange way: via NESTED LOOPS using child as a driving table. Here is a [...]

Funny Developer Tricks - first_rows(999999999)

I ran across a funny SQL statement recently (funny strange, not funny ha ha - well actually funny ha ha too I guess). It had a first_rows hint like so:

An Evening with Oracle Database Security Expert: Pete Finnigan

AMIS Technology School is proud to present, in collaboration with Miracle Benelux Masterclasses:

Miracle Benelux and Pete Finnigan agreed to do an extra special on the AMIS premises the evening just before Pete’s 2 day Masterclass in Utrecht will start (for the 2 day Masterclass agenda, see also the following URL). During this AMIS Query, besides the free food and normal standard setup of such an AMIS Query Event, Pete will have a presentation on Oracle security and there will be a lot of room of informal discussions during and after this session. There is still some room if you would like to learn from one of the best on Oracle database security.

Pete Finnigan

More details on those masterclasses can be found on the Miracle Benelux site. Hopefully this will be the first of series… More details about this event will follow shortly.

Oracle VM Single Box Install

A brother of mine asked me if I could create a database machine and an application server machine during this Easter bank holidays regarding a Demo/Proof Of Concept setup. Easter is always a lazy period, so why not…

The end result would be something like the following:

  • Disks setup RAID-1 configuration (2×146 GB)
  • OS: RedHat EL 5.4 x86_64
  • Application Server: JBoss 4.0.3 GA
  • Database Server: Oracle Database Server 10g R2 Standard Edition One

So I started doing some thinking. I had two HP ProLiant DL380 GL6 Server machines to work with, but both were “bare” minimum regarding their hardware. Every HP DL380 had 2×146 swappable SAS harddisks and only 2×2 GB RAM. Hmmm… Oracle License wise I would be in the safe zone because it would only be used as a demo / proof of concept environment and I also knew that the resource consumption would be the heaviest on the application server part. CPU probably wouldn’t be an issue due to the fact that even this starter model contained a Quad core Xeon Intel per machine.

I missed a lot of info, that in the end still could be crucial. For example database NLS/Unicode or JVM settings, software versions, SDK/JDK, etc, etc. Also it had to be easy maintainable and very decently configured due one of the facts that, my brother, or others probably could not maintain a Linux environment or even start one or start an Oracle database. And be honest, those boxes (although nice servers) were really bare minimum regarding harddisk volume sizes or RAM specs.

I came up with the following, probably not officially supported, but working idea…why not use Oracle VM…? In the end its a far more flexible solution…?!

Full House @MOW 2010 in Denmark

Wow, it will be a full house during Miracle OpenWorld 2010, as Moans announced during this video, maybe there won't be enough beds, maybe there won't be enough food, but Moans at least promised us, the 208+ attendees, the new Miracle Brew, anyway, have a look...