Using OLE DB to get SQL Server to connect to Oracle servers can be done quite easily, but there are a few little tricks you should know to make it go smoothly. Once it’s working it seems to work quite well. I hope this blog post will save you a few headaches.

Recently a client asked me to create a simple SSIS package that would connect to Oracle, pick up some data with queries they provided, import it to SQL Server, and eventually export the data as flat, delimited text files.

With SSIS you can use the OLE DB provider that Oracle provides. If your SQL Server is 32-bit, you can install the 32-bit Oracle client and stop there.

If it’s 64-bit, there are a couple different ways to get the Oracle providers working. Read the rest of this entry »

Welcome to the 152^nd edition of Log Buffer, the weekly review of database blogs.

PostgreSQL

Courtesy the United States PostgreSQL Association, the big news: PostgreSQL 8.4 Released!.

Josh Berkus writes, “Now that PostgreSQL 8.4 is out, I thought I’d write a little about my favorite 8.4 feature. As Mr. Performance Whack-a-Mole, what makes me happy about 8.4 is the ability to whack moles faster … which is why I’m very fond of pg_stat_statements.”

On ad’s corner, Andreas Scherbaum says, “Up to PostgreSQL 8.3 it was only possible to grant (and revoke) permissions on the entire table. If column level permissions were needed, a workaround like a view solved (more or less) the problem . . .  This . . . is uneloquent, error prone and does not scale well.  . . .  PostgreSQL 8.4 solves the problem with a shiny new feature: column level permissions.”

David Fetter looks into WITH (so much drama in the CTE): ” By now, you’ve probably seen that PostgreSQL 8.4 can produce Mandelbrot sets . . . but what are Common Table Expressions really about? Read the rest of this entry »

Recently, I tested a switchover on Oracle 11g SE1.

As you know, Oracle Database Standard Edition One—as well as Standard Edition—does not have the Data Guard feature. Therefore, I had to do everything manually.

The whole process took less than 15 minutes. This includes less than five minutes of full downtime to restart the database in READ-ONLY mode, and less than 10 minutes of READ-ONLY downtime.

Of course, it depends on the size of Redo logs and the network speed to move Redo logs from the primary server to standby.

Here is what I had. The primary database and one physical standby database:

• OS - SUSE Linux ES10 (SP2) x86_64
• Oracle - Release 11.1.0.7.0 64bit SE1

First of all, I switched the standby database to the primary role.

Read the rest of this entry »

A short time ago I posted how I was Using XtraDB Backup to backup InnoDB. Overall, the blog post was positive, but experiences that others have had (and commented to on that blog post) have made me want to put out another short article about using XtraDB backup.

The first few points remain the same — the backup process is stable, we were able to use the binaries without compiling, and using Innobackupex as the wrapper script, analogous to Innobackup.pl.

However, we did figure out why Xtrabackup had to be run as the mysql user:

Xtrabackup writes to the data dictionary file (ibdata1, for example). We have not examined if it also writes to the data and index files (still ibdata1 by default, or the .ibd files when using innodb_file_per_table). [EDIT: The authors of Xtrabackup have commented below as to why the write occurs:

xtrabackup is kind of very small and restricted instance of InnoDB, and reuses a lot of InnoDB code.

InnoDB by default requires O_RDWR option on ibdata1 files at start, and xtrabackup therefore also did that. In the latest push to trunk it was fixed, now xtrabackup opens file with O_RDONLY flag.

When the new version is released, we will be sure to test it so that we can run the backup as a read-only user, and report back.]

On the one hand, Xtrabackup is a free tool. On the other hand, modifying InnoDB’s underlying files risks corrupting all the InnoDB tables in the system. Which is a tricky situation when it is your backup tool that might cause corruption that is beyond repair, as you do not know if you can trust your backups.
Read the rest of this entry »

Hi All!

This year, the International Free Software Forum celebrated its 10^th anniversary. It happened last week in Porto Alegre.

Pythian presented a session on Thursday called 8 Rules for Designing More Secure Applications with MySQL.

As promised, here are the slides we used on that session: 8 Simple Rules to Design Secure Apps with MySQL (PDF).

Cheers!

Welcome to the 151^st edition of Log Buffer, the weekly review of database blogs. We’re going to take a fast tour through the best blogs from the week gone by, beginning this time, with Oracle.

Jonathan Lewis writes, “It occurred to me recently that I might be making casual use of terms that weren’t necessarily very well known to the less experienced user. So I’ve decided to build a glossary of terms – and I’ll try to add to it from time to time whenever I have a few minutes.”

Jonathan might want to add “Method R” to the glossary. Cary Millsap was making it understood, as he shows in Profiling with my Boy: “Today I’m going to raise the stakes, because yesterday I think I explained Method R so that an eleven year-old could understand it.”

Vivek Sharma offers a thorough look at the Cost-Based Optimizer: Inefficient Input yields Inefficient Output. Vivek begins, “Cost Based Optimizer has always been a mystery for most of the Database Administrators and Developers.  . . .  Cost Based Optimizer has improved a lot in previous few versions. Therefore, it can be said that CBO is still undergoing some enhancements. With these enhancements, Oracle Users have accepted the fact that the Application Performance might degrade after version upgrade . . . ”

Randolf Geist had some info to share on the matter of locked table statistics and subsequent create index. “ . . . in 10g and later index statistics are generated along with an index creation  . . .  so a newly created index usually has computed statistics. 10g also introduced the option to lock table statistics. Now if you lock statistics in 10g in later  . . .  and create an index on a locked table the statistics for the index will not be generated along with the CREATE INDEX command.”

Rob van Wijk gave us part three of his series on fast refreshable materialized view errors: aggregate MV’s. “In the third part I’m going to examine all restrictions for aggregate materialized views, as described in the documentation.  . . .  So this will be quite a lengthy and even tedious post, as you can imagine by the list above … but for a good cause.”

Read the rest of this entry »

Reanimating the Sydney MySQL User Group!

What: Sydney MySQL User Group meetup #7 - The Reboot

When: July 16, 2009 5:30 PM (please don’t forget to RSVP yes/no/maybe)

Where: Sydney, CBD - join the meetup for exact location.

We are back! After 3 years of being silent, SMUG (can I call it so? I know there are conflicts with other acronyms) resurrects the meetings.

The logistic of the meetup is the following:

• 5:30pm — the gathering starts and we have pizza and beers and talking your peers
• 6:00pm — we start the presentation
• 7:00pm — break and peer networking consuming the leftovers
• 7:30pm — we have an open (but slightly moderated) discussion. Topic is TBC. Perhaps, we can talk about future of MySQL now that Oracle’s bought Sun?

Read the rest of this entry »

My old friend and collaborator Theo Schlossnagle at OmniTI posted his slides from his Scalable Internet Architectures talk at VelocityConf 2009.

The slides are brilliant even without seeing Theo talk and I highly recommend the time it takes to flip through them, for anyone who is interested in systems performance. If anyone took an mp3 of this talk I’m dying to hear it, please let me know.

For those of you unfamiliar with OmniTI, Theo is the CEO of this rather remarkable company specializing in Internet-scale architecture consulting. They generalize on Internet-scale architecture, not on one specific dimension the way Pythian specializes on the database tier. This allows them to see Internet-scale workloads from a unique systemic, multidisciplinary point of view; from the user experience all the way up the stack, through the load balancer (or not), the front-end cache, the application server, the database server, the operating system, the storage, and so on. This approach lets them build Internet architectures and solve scalability problems in a unique and powerful, wholistic way.

Pythian first collaborated with OmniTI in 2001, and they deserve all of their success and profile that they’ve built since then. Trivia: both Pythian and OmniTI were founded in September 1997 and both companies continue to be majority-owned and controlled by founders (in Pythian’s case, yours truly).

Here’s the slide deck. Let me know your thoughts.

Welcome, readers! It’s time for another update to our series of posts on installing Oracle on Ubuntu Linux. In this edition, we’ll be installing Oracle 11g R1 on Ubuntu 9.04, both 32-bit.

This time, I’ve used VirtualBox to run a virtual machine (VM) to perform our work. (Virtualization has a number of advantages; in this case, I made several trial installs, trying different combinations and configurations. Having a pristine, basic set-up accelerated the whole process, since I didn’t had to reinstall from scratch on every new attempt.)

You might want to review the previous editions of this series, as there are technical references on this text fully detailed on previous posts. See these HOWTOs for Ubuntu:

• 8.10 - Intrepid Ibex
• 8.04 - Hardy Heron
• 7.10 - Gutsy Gibbon
• 7.04 - Feisty Fawn

Since we’re installing on a VM, we’ll be using Ubuntu 9.04 32-bit Server edition, , so let’s download it and check the MD5sum:

user@jackalope:/media/trezentos/downloads$ md5sum ubuntu-9.04-server-i386.iso
20480057590ff8b80ad9094f40698030  ubuntu-9.04-server-i386.iso
user@jackalope:/media/trezentos/downloads$

Download Oracle Database 11g Release 1 (11.1.0.6.0), and verify the provided cksum:

Read the rest of this entry »

What: Sydney Oracle Meetup #7 - Advanced Queuing in E-Business Suite
When:Tuesday, June 30, 2009 5:30 PM (please, make sure to RSVP yes/no/maybe)
Where: Our standard location in Sydney CBD

Welcome to our meetup #7! This meetup will be focused on Oracle Advanced Queuing (AQ) feature and its usage in Oracle E-Business Suite.

For inexperienced SOM members, we are starting with the meet & greet and pizza+drinks at 5:30 pm and move to smart things at 6:00 pm. We will be there until about 8:30pm (some are sticking around a bit longer while some might take off a bit earlier) and will have a break in the middle. The second half is generally more open-ended as most of you already know.

So what are the goodies at this meetup?
Read the rest of this entry »