ASM Rebalance Too Slow? 3 Tips To Improve Rebalance Times

see-saw

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...)

DBAKevlar at Collaborate 2015

Here’s a quick guide to my schedule of sessions at IOUG Collaborate 2015 for this year.  I’m looking forward to seeing everyone next week, (I’ll be arriving on Saturday, so I really should say in a couple days) and have no doubt we’re up for another phenomenal conference at Las Vegas, this year at the Mandalay!

Additionally, there are some great opportunities in professional development at the IOUG Strategic Leadership Program.  I’ll be speaking with James (more...)

IOUG Collaborate 2015 – #C15LV

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...)

Paris Oracle Meetup (Jeudi 26 Mars 2015 @ 7pm)

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:

global_197134042Flash 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...)

TNSNAMES.ORA Learning

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 […]

Annonce : Oracle Database In-Memory Advisor

Oracle Database In-Memory Advisor est maintenant disponible.
Pour utiliser cet assistant, le "Database Tuning Pack" est nécessaire.

Plus d'information :
  • Page OTN
  • Note MOS 1965342.1

Complément : Tutoriels sur Oracle Public Cloud

Complément : Vidéos Oracle Public Cloud

Test MySQL on AWS quickly

Using sysbench to performance test AWS RDS MySQL hardware is an easy three step  operation. 

Sysbench creates synthetic tests and they are done on a 1 mil row 'sbtest' table that sysbench creates in the MySQL database you indicate. The test doesn't intrude with your database schema, and it doesn't use your data, so it is quite safe. The test is an OLTP test trying to simulate event operations in the database as it (more...)

Oracle Exadata X5: The Road To Ten Billion Dollars

money

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.

(more...)

Deprecation of Non-CDB Architecture in Oracle 12c

dead-end

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...)

Pre-Built Oracle Database 12.1.0.2 on VirtualBox

Step by step screenshots showing the installation of Virtual box and configuring pre-built Oracle Database 12.1.0.2 (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 […]

Complément : Analyse de performances via AWR Warehouse


Annonce : Workshop DBaaS

Un workshop sur le sujet DBaaS, à destination des partenaires Oracle, aura lieu le 4 et 5 mars à Colombes (France)
Plus de détails : http://eventreg.oracle.com/profile/web/index.cfm?PKWebId=0x1713052088

Oracle GoldenGate Processes – Part 4 – Replicat

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 12.1.2.0, there are now three distinct versions of a (more...)

MySQL Locking

Have you ever wondered if MySQL does Row Level Locking? Or wondered why are you getting the error:

ERROR 1205 (HY000) : Lock wait timeout exceeded; try restarting transaction

You get the error because your allocated time to hold a DML lock in a transaction exceeds the set limit. Usually the default limit to hold a DML row lock, set by innodb_lock_wait_timeout db parameter, is 50 seconds. If your transaction doesn't commit/rollback within 50 seconds (more...)

OTech Magazine – Winter 2014

OTech Magazine – Winter 2014

OTech Magazine winter 2014The 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.

deltalounge

Oracle AWR Reports: When IOStats Lie

graph

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...)

New Cookbook: Oracle Linux 6 Update 5 within an Oracle VM Template

Oracle-VMI’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, Cookbooks, Database, Flash, Linux, Storage Tagged: cookbooks, database, oracle, oracle vm

Oracle database operating system memory allocation management for PGA

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...)