Oracle Real Application Cluster (RAC) becomes the technology of choice for highly available and highly scalable deployment of enterprise Oracle database environment. With its innovative technology it comes with no surprise its complexity. The complexity is not only with the underlying database technology itself, but also how well you design and implement it to work with other components including operating system, storage subsystem, etc. In order to setup and maintain a successful RAC environment, (more...)
Recreate control file with the new DB name, the old tried and tested method.Method 2:
Use new utility called NIDSteps to rename Databases using the new NID utility:1.) Stop database
2.) startup mount the database:
[oracle@testing1]~% srvctl status database -d test
Instance test1 is running on node testing1
Instance test2 is running on node testing2
srvctl stop database -d test
[oracle@testing1]~% sqlplus / as sysdba
SQL*Plus: Release 18.104.22.168.0 Production on Thu Jul 21 00:50:44 2011
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Connected to an idle instance.
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...)
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!!
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”
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