I’ve run into a few customers recently who have had problems with their ASM rebalance operations running too slowly. Surprisingly, there were some simple concepts being overlooked – and once these were understood, the rebalance times were dramatically improved. For that reason, I’m documenting the solutions here… I hope that somebody, somewhere benefits…
1. Don’t Overbalance
Every time you run an ALTER DISKGROUP <NAME> REBALANCE operation you initiate a large amount of I/O workload as (more...)
Like many other Oracle professionals and speakers I will be attending IOUG Collaborate 2015 this year in Las Vegas. I’m not a big fan of Las Vegas, but hey cannot turn down an opportunity to speak, especially when IOUG asked me to do more than one session.
This year my schedule is going to keep me busy; yet full of good topics that cover both EM12c and GoldenGate. If you are going to be (more...)
A quick post to say that this week, on Thursday 26th, I will be giving a talk (in English!) on the subject of Flash for DBAs (and architects, designers, developers, managers etc) at the Paris Oracle Meetup:
Flash for DBAs: A new technology is sweeping the world of storage. Flash, a type of non-volatile memory, is gradually replacing hard disk drives. It began in consumer electronic devices such as phones, cameras and tablets (more...)
If I have an alias entry named “TEST1″ in tnsnames.ora twice with different descriptions, which one will Oracle*Net use when connecting to database? What if the duplicate alias entry is in the IFILE referenced from tnsnames.ora – which entry will be used? In my tests, Oracle*Net reads the tnsnames.ora file from bottom up. So if there […]
Now that the dust has settled on the announcement of Oracle’s new Exadata X5 Database Machine, I’ve been doing some research in order to update my History of Exadata post (it’ll be ready soon). While reviewing the datasheets and other collateral for the X5 I was struck by the meteoric increase in one particular statistic: the number of processor cores on each database server. Oracle is riding that Moore’s Law train all the way to the bank.
Back in July 2013, Oracle released the latest version of its flagship database product, Oracle 12c. Among the usual fanfare was information about a number of new options – including one known as Multitenant. With the Multitenant option, databases use a new architecture which features a container database (or CDB) which in turn contains one or more pluggable databases (or PDBs). Use of Multitenant requires a licence – which at the time of writing retails at $17,500 (more...)
Step by step screenshots showing the installation of Virtual box and configuring pre-built Oracle Database 188.8.131.52 (including in-memory option). A quick way to get started on Oracle Database 12c. This is a very easy setup, though many do not know how easy it is to get started and playing with Oracle Database 12c on Linux […]
The replicat process is the apply process within the Oracle GoldenGate environment. The replicat is responsible for reading the remote trail files and applying the data found in cronilogical order. This ensures that the data is applied in the same order it was captured.
Until recently there was only one version of a replicat, that version was the classic version. As of 184.108.40.206, there are now three distinct versions of a (more...)
OTech Magazine – Winter 2014
The winter edition of OTech Magazine, the independent magazine for Oracle professionals, is available. In OTech Magazine – Winter 2014 subjects include:
- Time Series Forecasting in SQL
- Flashback – Empowering Power Users
- Starting WebLogic
- DevOps and Continuous Delivery for Oracle
- The Rapid Reaction Force – real time business monitoring
Download OTech Magazine Winter 2014 here.
If you’ve been unfortunate enough to follow my dithering on Twitter recently you’ll know that I’ve been lurching between thinking that there is and isn’t a problem with Oracle’s tracking of I/O statistics in its AWR reports.
I’m now convinced there is a problem, but I can’t work out what causes it… so step 1 is to describe the problem here, after which step 2 will probably be to sit back and hope someone far (more...)
I’ve posted a new installation cookbook for using Oracle within a virtual machine running on Oracle VM. Surprisingly, I was unable to come up with a satisfactory method of accessing external storage that did not involve the use of Oracle ASMLib…
Oracle Linux 6 Update 5 within an Oracle VM Template
Filed under: Blog
, oracle vm
This post is about memory management on the operating system level of an Oracle database. The first question that might pop in your head is: isn’t this a solved problem? The answer is: yes, if you use Oracle’s AMM (Automatic Memory Management) feature, which let’s you set a limit for the Oracle datababase’s two main memory area’s: SGA and PGA. But in my opinion any serious, real life, usage of an Oracle database on Linux (more...)