The latest from the MySQL community

In the meantime, don't forget the incoming webinar on Designing Scalable Architectures with MySQL …

I want to answer a simple question - If a query takes X milliseconds, how much of it is spent in the storage engine, and how much in the MySQL server? Why do I think is important? Well, since I am working on MySQL performance, I want to be able to place my bets on where to spend my time optimizing MySQL. Lets take an example. If a query takes 50ms, and I am able to figure out that 40ms is in the mysql server and the remaining 10ms is in the storage engine, the first place I would want to take a look at optimizing the MySQL server. This also tells me that it does not matter what the storage engine is, I am being limited by the server. Similarly if I find the storage engine taking up most of the time, I can explore alternate storage engines. I know all you mysql experts will tell me that much of the attribution (of time) has got to do with the capability of the storage engine, what features it supports, etc. and you cannot really do the …

Here’s a packed schedule. There will be a Sun crew visiting these universities between 16-17 July 2008. Will you be there? Where you’ll meet the rock stars:

• Wednesday, 16 July 2008, 9am - noon: Multimedia University, Cyberjaya
• Wednesday, 16 July 2008, 2pm - 5pm: Universiti Teknologi MARA, Shah Alam
• Thursday, 17 July 2008, 9am - noon: Management & Science University, Shah Alam
• Thursday, 17 July 2008, 2pm - 5pm: INTI, Subang

And what exactly will we be talking about? Besides the keynote, and tech demos, there will be focus on NetBeans (a fabulous IDE), an introduction to OpenSolaris, JavaFX, and of course, MySQL.

We all have 30 minute session slots, and the focus is rather developer centric, so I’m wondering what is best to cover in 30 minutes (what one can probably talk about in 5 days even)? Condensed talk on storage engines, index types, etc. ?

…

While I realize that part 2 to the Lucene stuff is still forthcoming… (err..sorry?!), there are some interesting things going on:

1. Giuseppe, John Loehrer and Jimmy Guerrero will host the webinar Designing Scalable Architectures with MySQL Proxy today. Jan and myself will also attend.

   So, if you are thinking about using the proxy or are simply interested in what people do with it, strongly consider attending this one.

2. There’s a quickpoll up on the MySQL website where we’d …

While I realize that part 2 to the Lucene stuff is still forthcoming… (err..sorry?!), there are some interesting things going on:

1. Giuseppe, John Loehrer and Jimmy Guerrero will host the webinar Designing Scalable Architectures with MySQL Proxy today. Jan and myself will also attend.

   So, if you are thinking about using the proxy or are simply interested in what people do with it, strongly consider attending this one.

2. There’s a quickpoll up on the MySQL website where we’d …

In my previous blog post I talk about GROUP BY and ORDER BY optimizations. A member asked a great question that I'd like to share with everyone.


But what if the query was:

SELECT c1, c2, c3, SUM(c4) FROM T WHERE c1 = ? GROUP BY c2 ORDER BY c3 DESC LIMIT 10;

That query would produce a temp table and a filesort.
explain  SELECT c1, c2, c3, SUM(c4) FROM column_test WHERE c1 = 1 GROUP BY c2 ORDER BY c3 DESC LIMIT 10\G
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: column_test
         type: ref
possible_keys: c1
          key: c1
      key_len: 5
          ref: const
         rows: 1
        Extra: Using where; Using index; Using temporary; Using …

KEY ACCOMPLISHMENTS LAST WEEK

• Constructed an experimental runtime data processing program.

KEY TASKS THAT STALLED LAST WEEK

• None

KEY CONCERNS

• None

TASKS IN THE UPCOMING WEEK

• Modify Skoll to use push-build tar balls for compilation and testing.
• Modify Skoll's data processing scripts for more detailed HTML results pages.

As you probably know MySQL Replication (statement based) works by fetching statements from MASTERs binary log and executing them on the SLAVE. Since MySQL 4.0 this process is a bit more involved having events passing via relay logs on the Slave which also means there are two replication threads "IO Thread" and "SQL Thread" used in the process but idea remains the same.

For replication to work properly you need to have proper "snapshot" - consistent state of the database as it was on master and corresponding position in masters binary logs. There are multiple ways to get the "snapshot" - shutting down MySQL Server and copying data, using LVM, Using Innodb Hot Backup Tool, Using another Slave, using backup image etc but in all the cases you have to be sure the snapshot you're dealing with corresponds to correct binary log position.

There are two sources of information for binary log position SHOW MASTER STATUS - this …

I’ve been working with what I used to call “utility computing” tools for about 6-9 months. However, for about the past 2 months, I’ve been seeing the term “cloud computing” all over the place, and there is so much buzz surrounding it that it’s reaching that magical point best described using Alan Greenspan’s words: “Irrational Exuberance”.

When Alan Greenspan used those words to describe the attitudes of investors toward the markets, what he was basically saying was that there were people who didn’t really know what they were doing, putting more money than they ought, into things they knew relatively little about. Further, he was saying that the decisions people were making with regards to where to put their money were a) bad, or at least b) not based on sound reasoning, or the ‘facts on the ground’.

This, I think, is where we are at with “cloud computing”. The blog post that put me over the edge is …