There was an interesting index related performance problem on Stack Overflow recently. The problem was to check an input string against a table that holds about 2000 prefix patterns (e.g.,
LIKE 'xyz%'). A fast select is needed that returns one row if any pattern matches the input string, or no row otherwise.
I believe my solution is worth a few extra words to explain it in more detail. Even though it’s a perfect fit for Use The Index, Luke it’s a little early to put it as an exercise there. It is, however, a very good complement (more...)
As of June 28, 2010 the Oracle APEX listener is available for download on the Oracle Technology Network (OTN) here
. The APEX listener in combination with a J2EE Web Server is a drop in replacement for Apache / ModPLSQL. Since Oracle Application Express (APEX) is deployed within an Oracle database (more...)
This article describes the effects of a high row migration rate on the clustering factor and the optimizer’s ability to select the best execution plan.
In my previous article—Row Migration and Row Movement—I have demonstrated that the “insert empty, update everything” anti-pattern can lead to 100% row migration. This article continues the research on row migration and unveils surprising effects on the clustering factor. To be precise, the clustering factor can become completely bogus in presence of a very high row migration rate. Once the clustering factor is “wrong”, it’s just a finger exercise to construct an optimizer (more...)
I've been pretty quiet lately, because I'm in a transitional period. After 10 years on documentation for Oracle Database and other enterprise server products, I'm switching to the InnoDB group that already works with MySQL. New development environments, new customers, it's an exciting time!A decade seems to be the right timeframe for me. It was 10 years at IBM before that. Check back in 2019, I'm
Recently was required to populate Country Name, Country ISO Code and Country Calling Code data in a table in the database.
Compiled data from various sources and finally came to the below data. Please use it for reference, this data is correct to best of my knowledge.
Incase you find that there is any problem please let me know.
Incase you need insert statement for database, please ask for them I will send them to you.
I hope this is useful!!
It's been a fortnight since Log Buffer
rounded up the reaction to the nascent No SQL movement
. But there is a lively thread still running on Oracle-L. The entire thread is worth reading
, but I was particularly struck by something Nuno Souto
"Now: the simple fact here is that folks from Google, Facebook, Myspace, Ning etcetc, and what they do as far as IT goes, are absolutely and totally irrelevant to the VAST majority of enterprise business."
This is so true. For starters, there is no SLA for users of Google's search engine. If Google doesn't include (more...)
Collaborate 09 starts on Sunday, May 3 (a few days from now!) in Orlando. I’ve been offline for several weeks (more on that later), but will be returning to the world of computers and technology in full force in Orlando. I’ve had a few inquiries about whether or not I’ll be at Collaborate, so I thought I’d resurrect my blog with a post about where I’ll be and some of the highlights I see at Collaborate 09.
First, where I’ll be presenting:
- Monday, 10:45-11:45am, #301, “Avoiding Common RAC Problems”
- Tuesday, 9:45am-12pm, #332, “Installing RAC From The Ground Up”
The RAC SIG, Oracle and IOUG are thrilled to present the hands-on event dubbed “RAC Attack!” at Collaborate09 in Orlando, FL. It is a half-day University Session in the IOUG Forum scheduled for the morning of Thursday, May 7th.
Each participant will have their own private RAC cluster to use. You’ll be able to install a new cluster, test session failover, perform backup and recovery and just about anything else you’d like to try (time permitting). The session will have lab outlines with very specific instructions that cater to beginners. Advanced users are welcome to test anything (more...)
I read an interesting article on RWW
about future of relational database
; thought it might be of interest to you too!
This article talks about the emerging database (key/value database) and compares it to RDBMS
. One of the interesting things being that you may not be able to perform JOIN operation. It is being described as the suitable model for cloud service provides (and pay-as-you-go service providers) and big players like Amazon (SimpleDB
), Google (AppEngine Datastore
), Microsoft (SQL Data services
) have already started the offering. There are non-cloud providers too like - CouchDB (more...)
This post is about a PL/SQL feature that doesn't get enough respect, "invoker's rights".First off, what's its real name? Depending on the source, you'll see the feature name spelled "invoker's rights", "invokers' rights", or "invoker rights". That makes a difference -- you'll get different results in Google depending on what combination of singular, plural, and possessive you use. And to be
Here's another ode to a small but fundamental aspect of Oracle, following the same theme as The Humble IF Statement. This time, let's look at the COUNT( ) function. I think when you look at it the right way, it opens up the whole story about database performance.What's the first thing you do when poking around an unfamiliar system? I'll bet it involves SELECT COUNT(*) queries in one way or