Showing entries 22696 to 22705 of 44109
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Gov 2.0 Week in Review

This week's review comes as the nation comes to grips with the expanding scope of its worst environmental disaster in living memory, as the extent of the oil spill in the Gulf of Mexico becomes more clear. Despite the dire circumstances, the fact that I was able to stream President Barack Obama's first address to the nation from the Oval Office using the White House app on my iPhone as I walked home was a reminder of new ways government can use technology to share information. When I arrived home, I was able to stream the rest of the speech from WhiteHouse.gov/live, coupled with real-time press reaction on Twitter. And after the speech, I watched a real-time YouTube question and answer session with Press Secretary Robert Gibbs and White House new media director Macon …

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Running MySQL Cluster as a Service on Windows

The MySQL Cluster daemon for MySQL Cluster (ndbd and ndb_mgmd) doesn't by themselves yet let them run as a service (apparently ndb_mgmd does, but I haven't seen it documented anywhere on how to do that). But there are ways to fix this, using some simple Windows tools and some registry hacking.

What you need to find is the Windows Resource Kit from some version of Windows that includes instsrv.exe and srvany.exe. It is not too picky with the actual version of Windows you run it seems, I used the Windows NT 32-bit versions of these on a 64-bit Windows 7 box, and it works just fine.

These two programs are simple and are easy to use:

  • instsrv allows you to install a service, it's real simple, just run the program and it will show the options (and these are few).
  • srvany allows you to run any odd program, that is not intended run as a service, do do this anyway.

Now, Google a …

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MySQL Cluster NDB MGM API on Windows

As MySQL Cluster is now available, and GA, on Windows, maybe it's time for some NDB API coding on that platform, right? The reason for this might, as it is in my case, be that Windows is a pretty good GUI Desktop platform, and MySQL Cluster / NDB really needs something like this. Those of you who have followed and used Cluster for a while, might remember my ndbtop tool that I created way back, and which is a MySQL Cluster monitor for Linux using ncurses. This is still useful I guess, but as far as a nice GUI presentation goes, ncurses leaves a lot to be desiered, to say the least.

So where do we start on Windows then? Well, to be honest, MySQL Cluster on Windows doesn't currently come with an installer, it's just a .zip file to unpack. But we are only using NDBAPI and the NDBMGMAPI, so that it no …

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Welcome googleCL
I am writing this blog post with Vim, my favorite editor, instead of using the online editor offered by blogger. And I am uploading this post to my Blogger account using Google CL a tool that lets you use Google services from the command line.
I am a command line geek, and as soon as I saw the announcement, I installed it in my laptop. The mere fact that you are reading this blog post shows that it works.


GoogleCL is an apparently simple application. If you install it on Mac using macports you realize how many dependencies it has and how much complexity it gives under the …

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The little-known Maatkit man page

The Maatkit toolkit for MySQL has a lot of functionality that’s common across the tools. It’s not a good idea to document this in each tool’s man page, of course. So there is an overall maatkit man page. It explains concepts such as configuration file syntax. This and all the other Maatkit man pages are online.

Related posts:

  1. How PostgreSQL protects against partial page writes and data corruption
  2. Writing a book about Maatkit
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The little-known Maatkit man page

The Maatkit toolkit for MySQL has a lot of functionality that’s common across the tools. It’s not a good idea to document this in each tool’s man page, of course. So there is an overall maatkit man page. It explains concepts such as configuration file syntax. This and all the other Maatkit man pages are online.

LaTeX output in grid export

Users of the latest HeidiSQL build file will find a new option when rightclicking a data grid: "Copy selected rows as LaTeX table". Same applies to the "Export grid data ..." which is capable of storing rows in LaTeX format to a file.

Thanks to brampton for the patch!

Now there are 5 different text formats supported in grid exports: CSV, HTML, XML, SQL and LaTeX. Probably you know some more reasonable file formats to support?

Disk seeks are evil, so let’s avoid them, pt. 4

Continuing in the theme from previous posts, I’d like to examine another case where we can eliminate all disk seeks from a MySQL operation and therefore get two orders-of-magnitude speedup. The general outline of these posts is:


  • B-trees do insertion disk seeks. While they’re at it, they piggyback some other work on the disk seeks. This piggyback work requires disk seeks regardless.
  • TokuDB’s Fractal Tree indexes don’t do insertion disk seeks. If we also get rid of the piggyback work, we end up with no disk seeks, and a two order of magnitude improvement.

So it’s all about finding out which piggyback work is important (important enough to pay a huge performance penalty for), and which isn’t.

This blog post is about one of the most …

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Keeping Up

I found I never published this post as it was sitting in my drafts few months now — it was written in 13th February, 2010. I’m publishing it without any changes.

I learn therefore I am!

I’ve just wrote few bits about learning a new technology and after skimming through my Google Reader, I noticed a great post by Chen Shapira — Deliberate Practice. That’s reminded me about another aspect of learning that I didn’t mention — learning is a continuous process.

There are two aspects…

  • No matter how good I am and how much I know, my knowledge and expertize become outdated relatively quickly these days unless I keep up with the new stuff. Unfortunately, there is so much new …
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PHP generated code tricks

Something that is great about PHP is that you can write code that generates more PHP code to be used later. Now, I am not saying this a best practice. I am sure it violates some rule in some book somewhere. But, sometimes you need to be a rule breaker.

A simple example is taking a database of configuration information and dumping it to an array. We do this for each publication we operate. We have a publication table. It contains the name, base URL and other stuff that is specific to that publication. But, why query the database for something that only changes once in a blue moon? We could cache it, but that would still require an on demand database hit. The easy solution is to just dump the data to a PHP array and put it on disk.

<?php

$sql = "select * from publications";

$res = $mysqli->query($sql);

while($row = $res->fetch_assoc()){

$pubs[$row["publication_id"]] = …
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