lunatechian (lunatech-ian)

one relating to, belonging to, or resembling lunatech

innodb and blobs

Are you planning on storing blobs in Innodb tables? If yes, think again. According to the manual,

InnoDB stores the first 768 bytes of a VARBINARY, VARCHAR, BLOB, or TEXT column in the row, and the rest into separate pages.

This translates into slower retrieval for blobs. However, InnoDB can skip reading blobs if they are not in select column list.

One solution for this is to keep blobs in a separate myisam table and do a join when you need the blob column.

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mysql bugs

If you are a heavy user of MySQL, I think you will appreciate this list of saved bug searches. For example, check out "p1_bugs_in_5.1" or "ActiveInnoDBBugs" These saved searches are also available as rss feeds.

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Mon Sep 29

In the morning I had to visit to the VFS office in Bangalore. The place has very strict security. I was carrying my laptop and the security person at the gate did not allow me to go in :-(. The man at the parking section said he could keep the bag, but he wanted 50 Rupees for that. I really lost my head when he told me the amount. Anyhow, I did not think it would be safe to leave the laptop with him. I will have to visit that office tomorrow again.

Due to time taken to visit the VFS office, I could not do much work at the office.

I had woken up at 6:00 AM today and that had given me enough time in the morning to do some emacs hacking. I really should spend time on learning lisp instead of copying stuff from random places.

Today my trainer at the gym changed my exercise schedule. It became quite grilling. However, I was able to get through the workout. Hopefully in 2-3 days time, I would be able to breeze through the workout.

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Sun Sep 28 2008

I spent the first half of my day working on some emacs customiation. I am writing a major mode for blogging and it is a good learning experience.

In the evening I watched 2 episodes of Star Trek, the original series. The plot was thrilling and the pace was good. Captain Kirk did not need to seduce alien women to protect the Enterprise :-).

As it was a weekend, I did not go to the gym today. I was very happy with my workout on Friday and I hope I would be able to maintain my pace in the gym tomorrow too.


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Trivia Time

An interesting bit of trivia. Ever wonder why the audio capacity of a standard compact disk is 74 minutes? Thank Beethoven - and Norio Ohga.

In the early 1980's, Sony was helping to develop a new digital music technology. Mr. Ohga, then the company's president, insisted that no matter what else, the new format had to be able to play Beethoven's Ninth Symphony without interruption. Mr. Ohga, you see, had been a classical vocalist before getting into electronics.

(Originally posted on my old blog on Fri, 31 Oct 2003)

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precise explanation of Seconds_Behind_Master value

Thanks to Artem Russakovskii for this nice explanation of what Seconds_Behind_Master means

In order to see if a slave is lagging, execute the 'show slave status' command and look for the Seconds_Behind_Master value. The way this value is calculated can be slightly ambiguous and unclear, so I'll explain. It is simply a difference between the 2 timestamps the time of the last received (and queued up in the relay log) query that already executed on the master and the time of the currently executing query on the slave.

As he says in the post, this value is not a precise indication of the replication delay.


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