I was curious about some of the databases I get to work with. “How do my clients store their data? What data types are most prevalent?” Well, a few keystrokes later, I had my answers:

SELECT c.data_type, count(c.data_type) AS frequency
FROM information_schema.columns AS c
INNER JOIN information_schema.tables AS t
ON c.table_schema = t.table_schema AND
c.table_name = t.table_name
WHERE c.table_schema NOT IN ('information_schema','mysql') AND
t.table_type = 'base table'
GROUP BY data_type;

Which gave me a nice “data type distribution” table:

Since the recovery from my recent outage, I’ve noticed that none of the normal feed sites where my posts normally show up caught the last post, so this is a test post to see what’s going on, if it was a temporary glitch, or what.

If you didn’t see the post linked above, please read it if you’re happy with your web host. I’m looking for a new one :-/

Ok, this blog is currently hosted by 1and1.com, and I think that needs to change, which is sad, because up until recently, I’ve been pretty happy with the performance. However, I recently had an issue, and some things came to light about my package that I wasn’t aware of.

First of all, the maximum time a process can run is about 6 seconds. Second of all, the maximum number of processes you can have running at once is 12. When I asked if this was a limitation of my *package*, the answer I got was that it was a limitation of all shared hosting accounts.

This blog started throwing 500 errors some time yesterday. I called support late last night and some lady said that she was running a tool that should fix my issue, and to call back in 30 minutes if the problem persists. Well, I’m sick as a dog, and it was late, so I went to bed. This morning, the problem was still there. I called support 3 times today, got cut off twice, and …

It was a clear sky in LA, but looking down, the city seemed to be covered in smog. After working on Sql Server 2008 material in LAX airport for a while, I boarded a turbo-prop for San Jose. Landing time was windy, so it was a bit bumpy. The only flight attendant, Cindy K, joked that “United throw in a few rides free of charge”. She was helpful with my luggage, with an easy smile.

So I checked in Radisson Hotel around San Jose airport afterwards. I booked the hotel through HotWire. It was a sweet deal, around 60 dollars per night. HotWire is a great site, especially for hotels. I’ve used it three times, all pretty satisfied.

Google map is awesome. It even provided me with information on how to get to Santa Clara convention center via public transportation. So I walked to the Gish station, saw Mexican, Moroccan, Japanese, and Chinese restaurants along the way, and got to the Santa Clara convention center in a jiffy. This is the …

Giuseppe Maxia blogs about the MySQL community dinner with some special guests in attendance.

I will take MySQL certification exams, therefore I am going through MySQL 5.0 Certification Study Guide. It is a pretty cool book in that it goes to the point right away without many wasted words. Too many technical books dance around the topic, fill the volume with screen shots, but do not deliver the goods in the end. I am reading the Safari online version. With so many pages, I can see the physical book can be bulky.

Anyway, some comments and observations:

1. Sybase, MySQL, and Sql Server’s definition and implementation of database and schema are somewhat close. I dislike Microsoft’s definition and usage of schema, especially in Sql Server 2005. It is very confusing to new or DBAs from other platforms.

Sybase, MySQL, and Sql Server all support the USE …

This article contains my notes and detailed instructions on setting up a MySQL cluster. After reading it, you should have a good understanding of what a MySQL cluster is capable of, how and why it works, and how to set one of these bad boys up. Note that I'm primarily a developer, with an interest in systems administration but I think that every developer should be able to understand and set up a MySQL cluster, at least to make the dev environment more robust.

Notes

• High availability. If one or some of the machines go down, the cluster will stay up, as long as there is at least one copy of all data still present. The more redundant copies of data there are, the more machines you can afford to lose.
• Scalability. Distributed architecture allows for load balancing. If your MySQL …

April 14-17th is going to be an exciting time. Why? Because the 2008 MySQL Conference and Expo is going to be held in Santa Clara, CA. Who would want to miss out on a chance to lurk around, let alone talk to, some of the smartest people in the MySQL world? Well, those who don't have at least $1000+, of course. A 3 day pass to the conference without tutorials costs a whopping $1199. A full pass would dry up your pockets $1499.

Well, "good news everyone". Thanks to Sheeri Cabral of The Pythian Group, PlanetMySQL.org, Jeremy, and, …

I downloaded Maatkit 1877 and installed it on a data archive server, then did a parallel dump of the data. I also did a regular dump of the same data using mysqldump. This isn’t a benchmark or even a real comparison, just me playing with Maatkit to get a feel for it and see how it can make my life easier. First, some stats about the database:

mysql> select table_name, table_rows from information_schema.tables where table_schema = 'somedb';
+------------+------------+
| table_name | table_rows |
+------------+------------+
| table1 | 24758808 |
| table2 | 33713412 |
| table3 | 221633443 |
| table4 | 56869734 |
| table5 | 14017081 |
| table6 | 77559278 |
| table7 | 48453337 |
+--------+------------+

mysql> call database_size_profile('somedb')\G
*************************** 1. row ***************************
…

As an independent consultant and trainer , I found myself doing a lot of existing code analysis and enhancement, mostly for stored procedures and ad-hoc SQL statements. I suspect a lot of people do the same thing as well, so I am really interested in learning how you do it. That’s the main purpose of this post. This post is tagged with Oracle, Sql Server, and MySQL, as the principals should be the same for all platforms.

Let me share with you how I do it. Notice that I look at table/column statistics and indexes in almost all the steps below. Therefore I purposely left them out in the discussion.

1. I always talk to the original author or the current owner of the code, asking him/her to walk me through it. I listen mostly, trying to understand why s/he writes code this way. I may ask a few questions, just to help me understand. I almost never do any lecturing at this stage. If the code is a stored procedure, I ask the author or …