Pythian Group

For the final day of UKOUG there are quite a few Pythian presentations. Unfortunately a lot of them happen at the same time, so it won’t be possible to attend them all live.

Using Oracle GoldenGate to Minimize Database Upgrade Risk

10:10, Media Suite
Marc Fielding

Even the best-planned database upgrades can leave nagging questions: what happens if my upgraded system performs unexpectedly? Is there a way I can go back to the previous version without downtime and data loss? Oracle GoldenGate allows DBAs to give affirmative answers to these questions. Drawing on upgrade experiences ranging from mid-sized databases to a large 10TB 90-CPU OLTP system, this session will show how to optimally configure Oracle GoldenGate, minimize downtime, maximize replication performance, and integrate Oracle GoldenGate into existing infrastructure such as Oracle ASM and storage-based replication.

Learn the various deployment scenarios where GoldenGate can minimize upgrade risk and delivery business value. Find out how GoldenGate can help not only during the upgrade, but after the upgrade as well. Learn how to use GoldenGate in medium- and high-volume environments. See real-world, tested GoldenGate configurations. Find out lessons learned and pitfalls to avoid.

The Answer to Free Memory Swap and Everything

10:10, Hall 8A
Christo Kutrovsky

Do I have enough memory? Why is my free memory so low? Am I swapping to disk? Can I increase my SGA (db cache) size? Can I add another instance to this server? Are my system resources used optimally? These are all questions that often haunt DBAs. This presentation is The Answer. It covers in detail the different types of memory, how to monitor memory, and how to optimally use it with Oracle. Multiple examples in the presentation demonstrate how certain actions on the database side cause different memory areas to be allocated and used on the OS side. Key underlying differences in operating systems approaches to managing memory will be highlighted, with special attention given to Linux and Solaris. Using Linux as an example throughout, this presentation explains how to effectively use tools such as “top”, “vmstat” and “/proc/meminfo” to look into into a system’s allocation and use of memory.

Amazon RDS, EC2 and S3 for Oracle Databases

11:20am, Hall 10B
Alex Gorbachev

This technical session focuses on specific recommendations and guidelines for leveraging the Amazon Web Services platform to host Oracle databases. We will looks into traditional database hosting using EC2 platform as well as recently introduced Amazon RDS on Oracle. We will look into how to configure, provision, backup, restore, monitor, and secure your databases in AWS. We will also look on how you can leverage S3 cloud storage for hybrid cloud deployments, particularly for backup and archival storage.

Backup and Recovery Roundtable

11:20am, Roundtable Area
Michael Abbey

A discussion of backup and recovery technology, problems and solutions. We will poll the attendees for an agenda on the day and proceed with an informal discussion not limited to:

RMAN, OSB, Sans, Data Guard backups, RAC backups and other topics of interest.

Concurrent Processing Performance Analysis for Apps DBAs

2:25pm, Hall 10B
Maris Elsins

Concurrent processing is one of the key elements of Oracle E-Business Suite, that’s used by most of modules for scheduling and processing background jobs. Keeping this functionality healthy is important to get maximum performance out of it. The paper describes the key metrics to estimate the performance of the concurrent managers, discusses approaches and techniques that can be used to understand how well the concurrent processing is set up, what are the bottlenecks and delays in processing of concurrent requests and provides tips on how to deal with each of the identified problem. This paper is targeted for Oracle Applications DBAs and technical consultants.

On tap for Tuesday is a 2-hour master class from Michael Abbey, along with an all-day drop-in RAC attack workshop with Alex Gorbachev and the RAC SIG.

Read the rest of this entry . . .

A mere 1 week until one of the treats of the year … off to Birmingham for the UKOUG show Monday the 5th through the 7th. My third time at this show and it was quite a treat each time. Brighton 1992 was my first voyage to the Mother Land and I was fascinated. I especially appreciated the painting on the crosswalks that reminded one to look right too before leaving the curb.  We stayed at the Metropole which was beside the Grand. There were small remnants visible in the front of the concrete that made up the facade of the Grand … October 12 1984 and thankfully Maggie (aka The Iron Lady) was ok after a bomb went off. October 1984 I was just getting started with Oracle (yes I first saw it when I was 8 :)).

My first venture into Europe was followed by a bevvy of trips into the continent in 1993, 1994, and 1995, ending up at the EOUG in Florence Italy where I gave a handful of papers. My presentations in Vienna in 1994 were a real eye-opener. Never before did I realize how quickly I speak and how poorly I tend to enunciate. Not until I had the opportunity to present to non English-language native attendees did I realize I had to slow down, speak clearly, and avoid idioms and colloquialisms.

As the mid 1990′s gave way to the soon-to-be new century, the Oracle tech space was teeming with techies and I had the pleasure of rubbing shoulders with early gurus such as Lewis (yes JL … none other), Niemiec, Millsap, Shallahamer, and Ellis. You could not go to the corner store without bumping into one of these techs. I have had the pleasure of giving more than 100 presentations over the past 22 years and keynoting for a handful of user group events in North America.

One of my first adventures into keynoting was a closing session at user group day which happens Sunday before Oracle Open World starts. I discussed little known facts about Oracle, the software we have come to know and love; for example:

1. There was once a time when Oracle had 2 versions of their server offering … one for the VAX cluster and the other for all other platforms. In early 1990′s, the version of the former was at 6.2 whereas the latter still at 6.0. Around the time 6.0.34 was released, Oracle “married” the 2 versions into something like 6.0.36. Thus the VAX cluster install base got the pleasure of upgrading from 6.2 to 6.0.
2. The terminal release of a very popular SQL*Forms 2 was called 2.3. A while after 2.3 came out, there was a major new release called 3.0. The user community was informed that they should upgrade to 3.0 as soon as possible as 2.3 was the terminal release. Quite some time after 2.3 was discontinued, the Applications customers noticed they were running an as-of-yet unheard of release called 2.4.
3. Oracle V6 was released in 1988 and had an add-on called TPO (transaction processing option). It contained, amongst other things, a procedural extension called PL/SQL. A few years after V6 hit the streets, Oracle realized Pl/SQL was the answer to the implementation of stored objects that appeared with Oracle7. TPO was retired and PL/SQL bundled with Orace7 at no extra charge.
4. The foundation of the PL/SQL implementation was (and still may be) for many yearsa handful of packages called PIDL, DIUTIL, STANDARD, and DIANA. Ok, who was Diana? As it turns out it was an acronym, of which the first “A” stood for “Ada”. Ada was used primarily by the US Department of Defence DoD), an extension of Pascal and a plethora of other languages used by DoD.
5. SCOTT/TIGER? Bruce Scott, an early developer at Oracle had a cat named Tiger.

I anticipate seeing people from all over the continent at UKOUG. The attendance over the past few years has been growing and nothing short of astounding. I am giving two papers at the show … one on a dear friend of us all called rman and the other on a close second … the physical standby. For me, even in the midst of emerging technology solutions, there’s still nothing like the old-fashioned Oracle CORE database arena.

Yesterday I was discussing with a fellow DBA about ways to check the status of existing and/or past RMAN jobs. Good backup scripts usually write their output to some sort of log file so, checking the output is usually a straight-forward task. However, backup jobs can be scheduled in many different ways (crontab, Grid Control, Scheduled Tasks, etc) and finding the log file may be tricky if you don’t know the environment well.
Furthermore, log files may also have already been overwritten by the next backup or simply just deleted. An alternative way of accessing that information, thus, may come handy.

Fortunately, RMAN keeps the backup metadata around for some time and it can be accessed through the database’s V$ views. Obviously, if you need this information because your database just crashed and needs to be restored, the method described here is useless.

Read the rest of this entry . . .

There are 2 configurable items related with RMAN encryption backup :

CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default

And there’s a snippet in Oracle Document:

• To create encrypted backups on disk, the database must use the Advanced Security Option.
• To create encrypted backups directly on tape, RMAN must use the Oracle Secure Backup SBT interface, but does not require the Advanced Security Option.

Here’s a test scenario of encryption RMAN backup sets on disk:

1) use Oracle Wallet Manager to store the encryption key

Add the following to sqlnet.ora on the host that you are backing up:

ENCRYPTION_WALLET_LOCATION =
(SOURCE =
    (METHOD = FILE)
    (METHOD_DATA =
        (DIRECTORY = /u01/app/oracle/admin/ORCL/wallet)
    )
)

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Hello Dear Reader,

This weekend was most probably my longest oncall weekend ever. As part of our work at Pythian each team member covers weekends on regular basis. There are quiet weekends and weekends like this one ;)

One of the tasks that I was involved in was 700GB database emergency cloning for an important functional issue troubleshooting. It was 10.2.0.5 (10GR2) 64 Bit database on Linux. I used the following command to clone:

export NLS_DATE_FORMAT='YYYY-MM-DD:HH24:MI:SS'

rman target / nocatalog auxiliary sys/syspwd@TARGET  log=dup_TERGET.log

run {
set until time "to_date('10-JAN-2010 23:05:25', 'DD-MON-YYYY HH24:MI:SS')";
allocate auxiliary  channel c1 type disk;
allocate auxiliary  channel c2 type disk;
duplicate target database to TARGET;
}

Read the rest of this entry . . .

I recently performed a migration from Oracle 10gR2 on Solaris to the same version on Linux, immediately followed by an upgrade to 11g. Both platforms were x86-64. Migrating to Linux also included migrating to ASM, whereas we had been using ZFS to hold the datafiles on Solaris. Restoring files into ASM meant we would have to use RMAN (which we would probably choose to use anyway).

As with many databases, the client wanted minimal downtime. It was obvious to us that the most time-consuming operation would be the restore and recovery into the new instance. We were basically doing a restore and recovery from production backups and archived redo logs. It quickly dawned on me that we could start this operation well before the scheduled cutover time and downtime window, chopping at least six hours from the downtime window. The client would only need to keep the new instance in mount mode after the initial restore/recovery finished, periodically re-catalog the source instance’s FRA (which was mounted via NFS), and then re-run the recover database command in RMAN. Once the time comes to cutover, simply archivelog current the original instance and shutdown immediate. Then open the new instance with the RESETLOGS option, and voila! Migration complete!

I’ll try to recreate a simple example here. Read the rest of this entry . . .

The story you are about to read is based on actual events. Names and paths have been changed to protect the innocent. I call this scenario “The Perfect Storm” because it took just the right combination of events and configurations. Sadly, this doesn’t make it an unlikely occurrence, so I’m posting it here in hopes that you’ll be able to save yourselves before it’s too late.

I have always had a preternatural dislike for using REDUNDANCY as a retention policy for Oracle RMAN, greatly preferring RECOVERY WINDOW instead, simply because REDUNDANCY doesn’t really guarantee anything valuable to me, whereas RECOVERY WINDOW guarantees that I’ll be able to do a point-in-time recovery to anytime within the past x days. Plus, I had already been burned once by a different client using REDUNDANCY. With the story I’m about to tell, this dislike has turned into violent hatred. I’m going to be light on the technical details, but I hope you’ll still feel the full pain.

Read the rest of this entry . . .

You can choose a DBID when you rename your Oracle database. This is probably a bad, unsupported, and useless idea. I assume this hidden feature can help you to mess up all your backups. So my advice would be: “don’t use it.”

I performed this test with Oracle 11.1.0.7 on Linux x86. It consists in using dbms_backup_restore instead of nid to rename the database. You’ll find below the few steps require to get to it.

Read the rest of this entry . . .