Hiring a MySQL DBA can be challenging, especially when the demand for MySQL DBAs is greater than there are qualified people to fill those positions. This article will go into some details on how to recruit, recognize, and interview a great MySQL DBA. (For the rest of this article, MySQL DBA and DBA are the same.)


1. Preparation

It's very important to determine your company's needs before starting your search for a DBA. Is your company a small start up, or a mature company that has a large replicated or clustered environment? Is this DBA position needed to support developers? Will this position support 24/7 operations? Will a smart candidate be able to learn as they go, or do you need a rockstar now that can handle your requirements from day one? By brain storming with various department managers or technical staff, the requirements will become clear as to what's expected for this position. Just like a software …

As I listened to today’s OpenNMS and Hyperic HyperCAST, it occurred to me that I haven’t posted a couple of previous archives. Which is a shame, because there have been some great ones.

HyperCAST 8 was all about upgrading to Hyperic HQ 3.2.x. It includes some live demos of upgrades in action, and covers upgrades for bundles, separate databases, and separate JRE’s.

HyperCAST 9 was Hyperic en espanol - and it was conducted completely in Spanish.

Enjoy! And remember, you can always register for upcoming HyperCASTs and view archives at hyperic.com/demo/hypercasts.html

Notice that I disabled comments to this post, so nobody will be tempted to ask for the code here. If you need the discount code, don't post comments. Send an email!

I’ve been waving my hands about lower bounds.  Well, sometimes I haven’t been waving my hands, because the lower bounds are tight.  But in other cases (lenient insertions, range queries), the lower bounds are very far from what we’re used to.

So now, for a bit of math:

Brodal and Fagerberg showed in 2003 that there’s a tradeoff between insertions and queries.  The insertions they consider are lenient.  Well, any lower bound for lenient is a lower bound for strict, but they also gave upper bounds, so it matters.  Also, they don’t know from lenient, but if you look at their upper bound, they are implementing lenient insertions.  The queries they consider are, unfortunately, point queries.  That’s too bad for us, because we’ve already seen that point queries are just too slow to be of interest on hard disks.

Still, they have matching upper and lower bounds, so let’s see …

Today Robin Schumacher, MySQL's Director of Product Management, announced that the mysql Falcon storage engine has moved into a beta release stage. Falcon, a new transactional storage engine introduced in mysql 6 (aka 5.2), has been in alpha for years. Other popular storage engines include MyISAM, InnoDB, which Falcon is supposed to challenge (successfully? :-/), and the upcoming Maria.

Falcon …

At Grazr, we store hierarchical data in MySQL. We have a query that I'm trying to optimize:

explain SELECT FROM child1 LEFT JOIN parent USING (fid) LEFT JOIN child1_text using (iid) left join child2 using (iid) where parent.indexed_varchar_col in ('abcd...', 'xyz123...' ) and (iid >= parent.iid_first) and (some_date <= now()) order by some_date desc

I get this:

*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: parent
type: range
possible_keys: PRIMARY,indexed_char_col
key: indexed_char_col
key_len: 96
ref: NULL
rows: 21
Extra: Using where; Using temporary; Using filesort

<3 more rows of explain, the same between two queries>

"Using temporary; using filesort" make this query much slower.

If I simply remove the order by: …

Today, I posted the solution (a sample project) for the NetBeans 6.0/6.1 Inserts Updates Deletes tutorial using MySQL.  I'll be posting solutions for other databases on this page.

This tutorial is a JSF application that demonstrates basic CRUD (create, read, update delete) operations on a database.
 

Today, I posted the solution (a sample project) for the NetBeans 6.0/6.1 Inserts Updates Deletes tutorial using MySQL.  I'll be posting solutions for other databases on this page.

This tutorial is a JSF application that demonstrates basic CRUD (create, read, update delete) operations on a database.
 

Yesterday's Los Angeles Times had an article about WikiMedia's financial difficulties. It's interesting to see that a professional core team is required to sustain even this uber-example of community volunteerism. This professional core team, in turn, needs to be paid, thus requiring a business model to sustain it.

So are we looking at a limit to what community volunteerism could achieve? Does this mean any large-scale effort would ultimately require a commercial aspect to stay relevant, as many open source projects have come to believe as well?

Perhaps in the end, none of us could ever escape the need to balance our social obligations with economic realities. Not that that is a bad thing: the whole point of a market-based economy is to allocate scarce resources, so that activities don't grow beyond what could be …

We’re pleased to announce that the Falcon beta is now out and available.  Falcon is MySQL’s new transaction storage engine, and offers a number of nice features for those developing applications that have transactional needs.  Falcon has all the standard transactional features you’d expect (ACID compliance, MVCC, crash recovery, etc) and some other items you will likely find helpful to have (user-defined tablespaces, SQL-based diagnostics for locking, I/O, and more.)

Please download the new Falcon beta (note that the Falcon beta is in the 6.0.4 alpha binary) and let us know what bugs you find or enhancements you’d like to see - your feedback is (as always) greatly appreciated! If you’re new to Falcon, you can check out the various tech white papers, getting started guides and FAQ’s on our 6.0 …