Dbvisit – Standby Database Technology Blog

We have released a new online service desk to further improve our support for Dbvisit. Tickets can be created online for any Dbvisit support issue. Tickets can be viewed and tracked at any stage to ensure progress is being made.

Any updates to the tickets will be automatically emailed to the person who created the ticked.

To create a new ticket in our service desk please go to: http://www.dbvisit.com/support.php

From the team at Dbvisit we hope you have a fantastic festive season, and a relaxing and enjoyable New Year.

We had our Dbvisit Christmas party and although not everyone was there because our team spans several countries, we had a great time.

2010. The Year Ahead.

We are excited about what’s in store for 2010. Work is already underway on a number of exciting plans and projects, which will bring significant benefit to new and existing customers. So what do we have in mind?

• A web based interface for Dbvisit
• 24×7 support services
• Helpdesk ticketing system

We look forward to communicating with you in 2010.

Warm regards.
the Dbvisit team

During recent testing, a datafile from one of our development databases was deleted. At the same time the same datafile was also deleted from the standby database. So this meant that our development primary and standby databases were no longer available.

However Dbvisit came to our rescue, and the functionality we have been recommending to our customers for a number of years now actually saved us! We employed Dbvisit to successfully recreate our primary and standby databases.

We have the following development servers:
Dev servers 1
dbvisit11 – primary database server
dbvisit12 – standby database server for dbvisit11

Dev servers 2
avisit31 – primary database server
avisit32 – standby database server for avisit31

Dev servers 2 are a clone of dev servers 1 with the same databases.
Due to the deletetion of the datafiles, the databases on dbvisit11 and dbvisit12 were gone.

Here is what we did to get the databases back on dbvisit11 and dbvisit12:

1. Logged onto avisit32 and used dbvisit_setup to automatically create a new standby database on dbvisit12.
2. Activated the standby database on dbvisit12 to become a new primary database.
3. Used dbvisit_setup on dbvisit12 to create a new standby database on dbvisit11.
4. Used graceful switchover to switch the roles between dbvisit12 and dbvisit11.

And so in 4 easy steps we had our databases back on our Dev servers 1: dbvisit11 (primary database) and dbvisit12 (standby database).

It is very rewarding to be able to use our own technology to recover a primary and standby database.

Oracle Open World 2009 is now behind us. It is a massive event that attracted 32,000 people and had about 1,900 sessions. It is very well organised by Oracle and partners. It is held in 3 huge convention centres that are across the road from each other. One road is permanently closed to traffic as they have erected big tents to use as lunch and entertainment venue. Almost the whole city of San Francisco is taken over by OOW as you see delegates walking with badges on the street wherever you are in San Francisco.

It was nice to meet up again with old friends and it was also a privilege to meet so many new Oracle DBA’s and Developers. OOW is certainly a place to bring the worlds best Oracle specialists together in one place. It is a great opportunity for networking and sharing knowledge and ideas.

My two presentations went very well and had a good turnout. One presentation was on Disaster Recovery and another on Perl. For details of my presentations and to download the slides and “homework” please go to OOW2009.

I think the Perl presentation hit a chord with many DBA’s as it is a highly effective tool for DBA’s, one that is too often overlooked, and one that many DBA’s would like to learn. But as with many programming languages you need someway to get you started, to learn the fundamentals and for someone to show you the right way to learn the language so that you do not start off with “bad” habits. This presentation was about how to start learning Perl and to go over some of the language fundamentals and best practices. The presentation was very well received as I received many positive comments from the audience. I was asked to submit this presentation for Collaborate 10 in Las Vegas next April which I now have done.

The Wednesday night party had everyone (all 32,000) transported in buses to an island in San Francisco Bay that is reachable by bridge. This was a huge party with 2 large stages. The entertainment was Aerosmith, Roger Daltry, Three Dog Night and The Wailers. What a great party and great food and drinks! I think Oracle hired all the buses, taxis and limos that are available in San Francisco.

What was the top new feature of Oracle 11gR2. For me this is “Edition-based redefinition”. As Tom Kyte said in his presentation: “It is the killer feature Of Oracle Database 11g Release 2. It is worth 2 features!”. It is like version control within the database. Not version control on the data itself but version control on the schema objects. The schema objects types that are editionable include Synonyms, Views and PL/SQL object types (like triggers, functions, procedures etc). So tables are not included in this.

Edition-Based Redefinition or EBR allows significantly less downtime when you are upgrading applications as you no longer need to wait for all the users to stop using the application before upgrading. Currently if releasing new PL/SQL code, the code needs to be recompiled but you cannot recompile until all users have stopped using the code. There are always a lot of dependencies when compiling PL/SQL, so basically it means no one can use the application when this is happening. With EBR, you can now compile the new code without affecting the current application. EBR is available in all editions of Oracle 11gR2.

In summary it was an event that was well worth attending and it was a privilege to be presenting at such a great event. Hope to see you there next year!

Every time I use Perl, I am amazed at this programming language created by Larry Wall. I have used several languages in the past, but Perl is now my favourite. It takes a little getting used to, but once you are used to it, it is great.

What makes it so great

• CPAN site. Small and large Perl modules that can be easily plugged into your code to make life easier. Some of the modules available are: logging, email, html template engines etc. There are over 70,000 modules.
• Runs on Windows, Linux, Mac and Unix as well as other OS. It is truly a multi-platform language. For each OS you do have to take certain precautions, but there are CPAN modules that allow you to deal with each OS’es peculiarities like file name conventions.
• It can be used in OO style but also conventional style.
• It is very efficient. With very few lines of code, a lot can be achieved.

I have read the following negative things being said about Perl:
- “Good for little programs, but not for large programs because you get spaghetti code.”
I think this is not true, in any language you can write spaghetti code. This is not due to the programming language but due to the programming style.

- “Things can be done in more than one way”
I think this can be a good thing or a bad thing. With Perl, I consider this a good thing as it demonstrates the power and flexibility of the language.
True this can mean that Perl can be a bit cryptic as you may be used to seeing things solved another way. However it is a great language if you are a perfectionist and always keen to learn new things. With Perl there is almost always a better way to do things and you learn all the time. At least I do.

True, Perl is not so trendy anymore as say Python, Ruby or Java. It is also cometimes difficult to compare different languages as some are more suited to a particular application than others. You also have to look at how well the language is known and how many resources are available. For example to build a website I would probably choose PHP over Perl as there are so many more PHP programmers in the world than Perl programmers ( I also like PHP).

If you are an Oracle DBA that likes to automate specific tasks, I would highly recommend using Perl. I used to do everything in Korne Shell, and I thought it was a great language. But once you learn Perl, you realise your hands are no longer tied behind your back!

Perl is great to automate some of the tasks that may be required in your disaster recovery plan. This can be changing tnsnames.ora entries, or DNS entries.

You are not in isolation if you use Perl in your organisation. Oracle 11g uses Perl to write some of their interfaces. For example asmcmd (and asmcmdcore) are witten in Perl. Vmware uses Perl for their installation routine.

CPAN

To install a cpan module, type cpan (in Windows use PPM. Start cmd and type ppm):

CPAN>i /mailer/

The i is for information, this will list all modules with the word “mailer”.

To install a particular module, you have to specify the name exactly as it appears:

CPAN> install Mail::Mailer
That’s it and you can use it.

How to learn Perl

The best way to learn Perl is to start with a small project. For example write a little Perl program that scans the Oracle alert log and send an email if an error appears. You will probably have Perl installed already because Perl comes pre-installed on Unix and Linux. On Windows go to activestate.com and download Perl.

The best Perl book in my opinion is Programming Perl by Larry Wall, Tom Christiansen, Jon Orwant.

So thanks to Larry Wall and all the great people that help support Perl and CPAN.

How much does 30 minutes of down time cost your business?

Maintenance overheads aside, think about the opportunity costs in lost productivity. Now imagine a 16 hour downtime. Will your company operations be hurt because of inaccessibility to critical data? In the US, 43% companies never reopen after a major disaster*, and only 7% survive for an additional 5 years**.

While we cannot control external forces – natural, human or technical; we can control the impact they have on our businesses. No company is immune to such catastrophes. Companies are protecting their data against disruptions more seriously today with contingency plans and standby servers, because of our excessive dependencies on machines.

Time or data loss has huge costs in terms of overheads and lost opportunities. Loosing integral data to disasters not only impacts the security and finances of your business, it jeopardizes its existence completely.

So the question is, how prepared are you to face such unforeseen situations? Do you have the peace of mind that no matter what happens, your company’s data will be protected and your business will continue without stalling even for a moment?

Your business success, bottom line, and growth depend on how prepared and secure your systems and processes are at all times.

You won’t ever have to recover from disasters, if you are ready for them.

(* US Small Business administration)
(** US Bureau of Labour)

We are very pleased to have SETRA Conseil as a Dbvisit reseller in France.  SETRA Conseil have a very experienced team of Oracle professionals with clients in Nice, Marseille, Montpellier, Lyon, Grenoble and  Paris plus Monaco. They are very experienced with Oracle Disaster Recovery, Standby Database, Oracle RAC and general Oracle consulting and can offer local Dbvisit support.

Welcome aboard.

I was very pleased to be invited by Francisco Munoz Alvarez to present at the first Chilean Oracle User Group. My presentation was scheduled on the 14th April (the second day of the conference) and we arrived well in time on the 11th of April. We were on the same flight as Francisco from New Zealand and he very kindly gave us a lift to the hotel from the airport. We had a few days to get used to the time differrence and enjoy the beatiful sites of Santiago. It is a very nice city and with a lot of interesting sites and places to see.

On the first day of the conference I had a chance to meet some of the Oracle ACE directors including Dan Morgan, Ben Prusinski, Robert Freeman, Hans Forbrich, Dennis Remmer, Tim Hall, Plinio Arbizu, Mauricio Naranjo and Graham Wood. It was a privilege to be presenting along side people that have given so much back to the Oracle community over the years.

Francisco did a great job of organising the whole event and most of it from New Zealand! The venue was great and the sessions were are also very interesting.

The second day of the conference it was time for my presentation. My paper was on “How to create a Technical Disaster Recovery Implementation plan“. The paper focuses on the plan of the actual implementation of the hardware and software at the disaster recovery location.
This plan ensures there are no unforeseen surprises when building the disaster recovery solution and that all critical systems and their components have been accounted for. This paper focuses mainly on Oracle centric applications in Unix/Linux environment. The Technical Disaster Recovery Implementation plan includes:

• Creating a technical register of applications and servers.
• Creating application consistency groups (different application must work together consistently to guarantee integrity in the data).
• Define a server mapping (either one-to-one or many-to-one). Will each primary server have its own disaster recovery server, or will several primary servers be consolidated to one disaster recovery server.
• Creating a configuration register for each primary server including OS, patches, firewall rules, etc.
• Software licenses and media considerations.
• Synchronisation methodology.
• Oracle standby database implementation.
• Best practise primary servers.
• Best practice standby servers.

I had to remember to speak slowly as everything was being translated from English to Spanish. I was very happy with the presentation and had a few questions at the end. Always a good sign I think!

During the social time, I had the pleasure of getting to know Ben Prusinski, Hans Forbrich, Dennis Remmer and Tim Hall a little better.

After the conference we were in Chile for another 4 days and did some more site seeing in Santiago and around the area.