The latest from the MySQL community

Database schema changes are not popular among DBAs, not when you are operating production databases and cannot afford to switch off the service during a maintenance window. These are unfortunately frequent and necessary, especially when introducing new features to existing applications. 

Schema changes can be performed in different ways, with tradeoffs such as complexity versus performance or availability. For instance, some methods would trigger a full table rewrite which could lead to high server load. This in turn would lead to degraded performance and increased replication lag in master-slave replication setups. 

This is the fourth installment in the ‘Become a MySQL DBA’ series, and discusses the different approaches to schema changes in MySQL. Our previous posts in the DBA series include High …

A Note On Good Practice

Even though I’ve been developing for some time now it never ceases to amaze me how many people don’t comment in their code. Most of us have fallen into the trap of “the code is self explanatory.” Sure, sometimes it is: if you’re writing “Hello World.” Even that can be questionable at times.

I once interviewed a seasoned developer who, when asked about how they document, replied “I think code should be self documenting.” I wanted to slap my forehead and send them packing right away. Code is never self-documenting. Never. Especially when you go back to it 4 weeks later. And if you think it is self documenting, the poor sap who has to maintain your code doesn’t.

With that said, I would like to make a plea to all non-documenters out there with good reasons on why you want to document.

Why Document? Visual Resting Place

Great …

Are your databases more costly than they need to be? If you’re not sure, this webinar will show you how to find out, quickly and easily, with KPIs that indicate overprovisioning or opportunity for driving more efficiency from your databases.

Join us on July 9th at 2 PM EST (6 PM GMT), as Baron discusses database cost reduction. The key topics you’ll learn are:

• Evaluating your current efficiency.
• Determining if there’s an opportunity to lower your database costs.
• Five simple steps to achieve maximum cost efficiency from your databases: query efficiency, consolidation, reduction of diversity, right-sizing, and cloud computing.
• For each step you’ll learn how to find out whether it applies to your situation, and how to take action on it.

After this webinar, you’ll understand how to measure, assess, and sometimes lower the cost of your database …

Prior to MySQL 5.7, the CREATE USER command had a number of limitations:

• No way to set both authentication plugin and password
• No way to disable a user
• No way to define user resource limitations
• No way to set a non-default password expiration policy
• No way to require SSL/x509

All of these things could be done through other means, but typically involved other statements, such as GRANT commands. Starting with MySQL 5.7.6, these can all be done through a new and improved CREATE USER …

Compiling MySQL Workbench yourself is quite a common task for Linux users, even though the application is available precompiled for certain platforms ready from our download page and available in our yum and apt repositories. In this blog post we show you how to compile it on Windows.

Introduction

Doing a build on Windows is a totally different matter and most users never need to do that. It’s mostly intersting for those wanting own functionality or just being curious. But you should be an experienced Visual Studio user. It’s a complicated task and not a good start for a beginner. The key problem when building on Windows is that we cannot ship any 3rd party library we used. Instead you have to collect them all yourself. In order to ease that task we created the list below. Each library comes with a version number which usually specifies the minimum version to be used. Most of the time it’s not mandatory to use the exact …

UMASK and UMASK_DIR are amongst few MySQL Environment variables which defines directory and file creation modes (file permissions). In this post we will understand using UMASK & UMASK_DIR for changing the database directory and file permissions from it's default to what we need.

The post UMASK & UMASK_DIR – changing default MySQL file dir permissions first appeared on Change Is Inevitable.

#DBHangOps 06/25/15 -- Even More Automation!

Hello everybody!

Join in #DBHangOps this Thursday, June, 25, 2015 at 11:00am pacific (19:00 GMT), to participate in the discussion about:

• What's the last script you wrote? Why?
• What's the last tool you wrote? Why?
• What's your most valuable or most used tool/script that you've developed?
• What's the first script/tool you get or build at a new job?

You can check out the event page at https://plus.google.com/events/c47c6h7c1jgl3ifptev1pnmrf5s on Thursday to participate.

As always, you can still watch the #DBHangOps twitter search, the @DBHangOps twitter feed, or this …

A question I often hear when customers want to set up a production PXC cluster is: “How many nodes should we use?”

Three nodes is the most common deployment, but when are more nodes needed? They also ask: “Do we always need to use an even number of nodes?”

This is what we’ll clarify in this post.

This is all about quorum

I explained in a previous post that a quorum vote is held each time one node becomes unreachable. With this vote, the remaining nodes will estimate whether it is safe to keep on serving queries. If quorum is not reached, all remaining nodes will set themselves in a state where they cannot process any query (even reads).

To get the right size for you cluster, the only question you should answer is: how many nodes can simultaneously fail while leaving the …

The consumerization of IT and the integration of BYOD throughout the enterprise in recent years has made the customer king. And this means the end-user experience has become critical. The latest figures show that if your site doesn’t do a full page load in 3 seconds or less, then your customers will leave and abandon you and head over to your competitors site to spend their money there. Customers simply have no patience for slow, erratic, or downed websites. And this is why keeping your business-critical applications running optimally and efficiently is crucial for the success of your organization. Without this you might as well close up shop.

Application performance monitoring is the key to ensuring that the …

VividCortex is sponsoring and exhibiting at O’Reilly’s OSCON in Portland, Oregon this year. We will be at booth 429, serving up hats and database monitoring demos.

Click here for more details and registration.