SQL tidbits are always valuable and highly searched for by newbies (as opposed to reading the SQL documentation). Sometimes we seasoned SQL developers take for granted little things like when a single- or multiple-character wildcard comparison works. It seems we know what newbies don’t. That you need a wildcard comparison operator not simply and equality comparison operator.

The question posed to me was, “Why doesn’t my wildcard comparison work?” Here’s a simplified example of their question.

SELECT 'Valid' AS "Test"
FROM    dual
WHERE  'Treat' = 'Tre_t'
OR     'Treet' = 'Tre_t';

Naturally, the answer is that the equality operator compares the strings based on their exact match (character sensitively in Oracle and character insensitively in MySQL). It needs to be rewritten by replacing the equals (=) comparison operator with the LIKE …

I registered yesterday for Oracle OpenWorld 2013, and I’ll look forward to seeing friends there. Having worked in the Oracle 12c beta for a year, I’ll be interested in the presentations. Also, hearing more about Java 7 at JavaOne. On the downside, I’m missing MySQL Connect this year.

Cloud computing offers many possibilities, and container and pluggable databases are a great solution. We’ve two new acronyms with the Oracle 12c release. A containerized database is a CDB, and a pluggable database is a PDB. I’m looking forward to seeing more about the provisioning of PDBs during the conference. If you’re new to the changes, check out CDBs and PDBs in Chapter 17 in the …

This article addresses the benefits provided from database virtualization. Before we proceed however, it is important to explain that database virtualization does NOT mean simply running a DBMS inside a virtual machine.

Database Virtualization, More Than Running a DBMS in a Virtual Machine While running a DBMS in a VM can provide advantages (and disadvantages) it is NOT database virtualization. Typical databases fuse together the data (or I/O) with the processing (CPU utilization) to operate as a single unit. Simply running that single unit in a VM does not provide the benefits detailed below. That is not database virtualization that is merely server virtualization.
An Example of the Database Virtualization Problem Say you have a database handling banking and I have $10MM in the bank (I wish). Now let’s assume that the bank is busy, so it bursts that database across 3 VM nodes in typical cloud-style.  …

This article addresses the benefits provided from database virtualization. Before we proceed however, it is important to explain that database virtualization does NOT mean simply running a DBMS inside a virtual machine.

Database Virtualization, More Than Running a DBMS in a Virtual Machine While running a DBMS in a VM can provide advantages (and disadvantages) it is NOT database virtualization. Typical databases fuse together the data (or I/O) with the processing (CPU utilization) to operate as a single unit. Simply running that single unit in a VM does not provide the benefits detailed below. That is not database virtualization that is merely server virtualization.
An Example of the Database Virtualization Problem Say you have a database handling banking and I have $10MM in the bank (I wish). Now let’s assume that the bank is busy, so it bursts that database across 3 VM nodes in typical cloud-style.  Now …

As there was a lot of complain recently about various cases with PERFORMANCE SCHEMA (PFS) overhead, I've decided to start a series of articles to help you to use PFS in the best way to analyze your workloads. This is the first part, starting with an overview of instrumentation problems generally..

First of all, instrumentation cannot be free! - when you want to trace or get some stats about your application internals you're adding a new code, and this code is increasing an overall code path, so your final binary simply cannot run on the same speed by definition!.. Of course, if your instrumentation code is poor, the overall overhead will be bigger ;-) but if you're designing it well, it'll be lower, but still not zero!..

Dynamic instrumentation brings additional cost - as soon as you're willing to add some advanced stuff within your instrumentation, it makes sense to not keep it active all of the time.. - …

When analyzing response time, or latency, you need much more information than an average provides. The average, commonly the arithmetic mean, shows the index of central tendency. But, as I found in earlier posts, the tendency is often not central, but may be skewed by outliers, or split by multiple modes. How often these factors occur was determined quantitatively, using tests and a survey of hundreds of production servers and different types of latency: over 95% had six-sigma outliers, and at least 20% had multiple modes. While these numerical results are useful, nothing beats a visualization, such as a histogram, …

An article I wrote was posted to the Facebook Engineering blog, about the automation system I worked on at Facebook for MySQL Database Provisioning.

It covers, in fairly intimate detail, a system called "Windex" that we use to provision and re-provision our MySQL databases at Facebook. This system basically provisioned the new Facebook Datacenter in Luleå, Sweden, with very little human effort, saving us loads of time.

So, if you're curious about some of what it is that has been taking up all my time for the last year and some, or if you're just always curious about how Facebook is doing things, go check it out.

Lefred and I spent a bit of time making innotop 1.9.1.
We’ve released a new version mainly to include MySQL 5.6 support as well as including some bugs fixed by Baron Schwartz and Frédéric Descamps.

You can download the .tar.gz and rpm’s (new!) at
http://code.google.com/p/innotop/downloads/list

Bugs fixed:

• Issue 71: DBI prints to STDERR instead of just throwing an inactive statement error
• Issue …

There is a tsunami of blog posts out there as Oracle has made public its 12c database and SQL Server and MySQL with numerous new offerings. This Log Buffer Edition covers a few salient blog posts.

Oracle:

Among the major ETL tools in the market , Oracle Data Integrator outshines not just for a couple of reason. Oracle has invested a lot in developing the tool after it took over from Sunopsis.

You want to learn more about innovative features of WLS 11g and 12c? You want to get answers about the roadmap and capabilities?

Kristin Rose tells us that 12c  offers the latest innovation from …

Here are 3 recent ' oops... wish I hadn't done that :/ ' mistakes I've made since joining moz that you might as well avoid (I'm sure there will be more, but they better not be the same)

Reviewing config files for MySQL, but not all of the defaults 

    We recently migrated a few MySQL databases to a new datacenter, and took advantage of the migration to upgrade the MySQL version(s) at the