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Showing entries 1 to 20 of 18310 Next 20 Older Entries
memcached and the client: Database UDFs
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NorthScale's own Patrick Galbraith has, for many years now, authored and maintained the MySQL, and now Drizzle, UDFs for memcached.  Last week, Patrick took this one step further with the latest release, version 1.1, which now includes support for "check and set" (a.k.a. CAS) operations.  

User Defined Functions are available for a number of different databases.  This allows some kind of stored procedure language or other triggers to execute other code imported into the DB.  In the case of the memcached UDF, this means giving stored procedures the ability to call memcached operations.

The general idea here is pretty simple.  Most applications start with a database, though it's always possible to use web services or flat files.  Regardless of where the data is

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Installing Apache2 With PHP5 And MySQL Support On Ubuntu 9.10 (LAMP)
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Installing Apache2 With PHP5 And MySQL Support On Ubuntu 9.10 (LAMP)

LAMP is short for Linux, Apache, MySQL, PHP. This tutorial shows how you can install an Apache2 webserver on an Ubuntu 9.10 server with PHP5 support (mod_php) and MySQL support.

A Laptop for Developers without paying The Windows Tax
Employee +1 Vote Up -1Vote Down

I find it amazing that the U.S. Department of Justice can continue to cover its eyes and ears while Microsoft is allowed to exert its monopolistic power over all hardware manufacturers.

About 20 months ago, I was able to purchase a Lenovo Thinkpad T61 from the lenovo.com website without an operating system installed. Today, I went to purchase a new Lenovo Thinkpad laptop, again without having to pay the Windows Tax. Turns out Lenovo has stopped offering this option. What a complete PILE OF SHIT. Somebody in Microsoft's "Business Development" or "Partners" team must have told Lenovo to stop offering its customers a simple choice of not having to pay the OEM license fees for Windows. And there's nothing anyone can do about it. Microsoft is

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451 CAOS Links 2009.11.24
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Chrome OS and Andoid to merge - eventually. Oracle and SpringSource propose Eclipse OSGi project. And more.

Follow 451 CAOS Links live @caostheory on Twitter and Identi.ca
“Tracking the open source news wires, so you don’t have to.”

For the latest on Oracle’s acquisition of MySQL via Sun, see Everything you always wanted to know about MySQL but were afraid to ask

# Gizmodo reported that Chrome OS and Android are destined to merge, somehow.

# Q&A with open government activist David Eaves about Portland’s move


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Software preview MySQL Scriptable Replication
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Fig. 1 MySQL per-row replication filtering

Fig. 1 MySQL per-row replication filtering

A MySQL Software preview is available which allows you to write Lua scripts to control replication on a statement-by-statement basis. Note that this is prototype functionality and is not supported but feedback on its usefulness would be gratefully received.The final version would allow much greater functionality but this preview allows you to implement filters on either the master or slave to examine the statements being replicated and decide whether to continue

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group date
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A non-rigorous, non-scientific, totally off-the-cuff test of which function to pick when you need to group by year and month.

I populated a table with 262K rows of random dates, and then ran

SELECT %s, COUNT(*) FROM table GROUP BY %s ORDER BY NULL

with various functions, which should all result in the same grouping. I repeated each query five times and show the average time, using three different column types DATE, DATETIME, and TIMESTAMP.

expression DATE DATETIME TIMESTAMP
EXTRACT(YEAR_MONTH FROM d) 0.362 0.369 0.581
LAST_DAY(d) 0.374 0.389 0.582
DATE_SUB(d, INTERVAL DAY(d) DAY) 0.429
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MySQL University: Speakers for 2010 wanted!
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We'll soon have our last MySQL University session for this year, followed by a winter break until the end of January 2010. So far there's only one session scheduled next year, but we'd like to have one session per week, so we need lots more speakers!

Anyone who has something technical to say about MySQL qualifies as a speaker. MySQL University sessions take place on Thursday afternoons European time, and normally have between 20 and 30 attendees, but quite a lot of people listen to the recordings when the live session time isn't convenient for them. We're using Dimdim as our conferencing system, so the setup for speakers is very simple: Just grab a headset,


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Windows XP -> Cloud -> Windows 7
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We recently added support for Windows 7 to both Zmanda Cloud Backup and Amanda Enterprise. Zmanda Cloud Backup stores its backup archives on the Amazon S3 Storage Cloud. Amanda Enterprise has the option to do so. Users can backup both the Windows file systems and system state, as well as various Microsoft applications, Oracle and MySQL databases. Now we support all Windows versions supported by Microsoft, including Windows 7.

To upgrade from Windows XP to Windows 7, Microsoft recommends users to backup their Windows XP to external hard disk and then install Windows 7. Backup to (and Restore from) Cloud offers another

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Improved read-only load balancing with MySQL Proxy 0.7.x
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A customer had come to us this week asking about some of the functionality in the ro-balance.lua script that ships with MySQL Proxy. As I investigated things further, I came to realise that due to some changes in the 0.7.x series, the script was broken.

Being the helpful fellow I am, I updated the ro-balance.lua script so that it works again. I also ended up making some nifty improvements...

For those of you unfamiliar with the ro-balance.lua script, it is designed to do the following:

  • proxy new connections to a pool of slaves 
  • periodically check that slave IO thread is running and slave has not fallen too far behind
  • take slaves determined to be offline or otherwise unfit for use (see above) out of the pool
  • fall back to the master server if no slaves are available at all


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Restore one table from an ALL database dump
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A lot of the time I have found that the only available backup taken from mysqldump contains all databases. This is ok but can be a head ache if you only need to restore one or some of the tables in one database. Below is a good way to restore only that which needs to be restored. I have created three tables in the test database, truncated the third table and now need to restore just that table.

-- Example:

mysql> select database();
+------------+
| database() |
+------------+
| test |
+------------+
1 row in set (0.00 sec)

mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| tbl1 |
| tbl2 |
| tbl3 |
+----------------+
3 rows in set (0.00 sec)

mysql> select min(anum), max(anum) from





















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Pluggable Database Client Tool
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A few weeks ago I wrote about a student group who will be working with the Drizzle community to build a new database client tool. While the tool will be the primary replacement for the Drizzle client tool, we hope it will be generic (using the Python DB API) so it will work with others like MySQL and PostgreSQL. We’ve had a number of great discussions, including a session at OpenSQL camp last weekend. I wanted to toss out a few ideas of how such a tool could be structured to allow for maximum extensibility.

One possibility is to borrow from typical Unix shells and DSP processing systems where you have a number of modules with I/O interfaces and data exchange formats between each module. Each module provides a specific signature so you know what other modules it can plug into. Here is a simple example:

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NoSQL vs MySQL
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No I did NOT post the following comment

This is ridiculous. You didn't test MySQL, you tested a failing DNS lookup on authentication.

resulting in the follow up post :


My previous post Redis, Memcache, Tokyp Tyrant, MySQL comparison had a flaw as pointed out by this comment. The MySQL was taking a huge time for doing a reverse DNS lookup.

But as always ... Everything is just a Freaking dns problem :)

Technorati Tags:Technorati Tags:




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Fast UNION support now in InfiniDB
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While at MySQL, one of the complaints I used to receive every now and then had to do with MySQL’s performance in the area of UNION’s. I distinctly remember one user group meeting where folks from one government agency told me they couldn’t use UNION at all in their application because the performance was so slow.


Now this isn’t always the case with MySQL, but I’ll admit I have seen bad speed on some UNION queries. And that’s one of the reasons I&rsquRead More...

MySQL University: The Spider Storage Engine
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This Thursday (November 26th, 14:00 UTC), Giuseppe Maxia will present the Spider Storage Engine. This session was originally scheduled for October 15th but had to be postponed for technical reasons.

Here's from the abstract: Everybody needs sharding. Which is not easy to maintain. Being tied to the application layer, sharding is hard to export and to interact with. The Spider storage engine, a plugin for MySQL 5.1 and later, solves the problem in a transparent way. It is an extension of partitioning. Using this engine,


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The Affero GPL does not solve the open source/cloud revenue dilemma
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A number of people have recently raised the issue of the threat that cloud computing poses to the monetization of open source by specialist vendors, including Savio Rodrigues, Matt Asay, and Mike Hogan.

I believe that cloud computing provides an opportunity for open source specialists, but agree that cloud services based on open source code could potentially eat into the business opportunities for open source specialists since the cloud providers have no requirements

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Redis, Memcached, Tokyo Tyrant and MySQL comparision (rectification skip-name-resolve)
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My previous post Redis, Memcache, Tokyp Tyrant, MySQL comparison had a flaw as pointed out by this comment. The MySQL was taking a huge time for doing a reverse DNS lookup.

I turned on the skip-name-resolve parameter in the my.cnf and the Throughput of MySQL grew considerably, almost more than double.

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My swap space on an SSD?
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I had an interesting discussion with 2 colleagues about the possible interest of putting the swap space of a system on a SSD.

If I consider the gain in latency that an SSD brings versus a capacity disk - in the region of 100x - the solution seems obvious. Swapping - or more precisely paging - must be much faster/ with an SSD. Since RAM is expensive versus SSD, I could even be tempted to design a system with a small amount of RAM and a large amount of swap space on SSDs. In other words, I can ask myself if trying to prevent my system to page is still a good fight?

Let's try to shed some light on these questions.

Paging takes place when my system runs out of RAM because more processes are created or because existing processes requires more memory (check this


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Storing IP addresses in a MySQL data table
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For a lot of log processing, I need to store IP addresses in a database table. The standard process was always to convert it to an unsigned int in perl or php and then insert it. Today I discovered an easier way. MySQL's INET_ATON function. It takes an address in dotted quad format and converts it into an INT. So, all you have to do is this:
INSERT INTO table (ip) VALUES (INET_ATON('$ip_address'));
And done.
Connector/MXJ 5.0 (GA 5.0.11, published on Monday, 23 Nov 2009)
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Connector/MXJ 5.0 (GA 5.0.11, published on Monday, 23 Nov 2009)
FORUM PHP 2009 PARIS
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rance FORUM PHP 2009 was held last week in Paris (12th and 13th nov) at Cite des sciences et de l'industrie Thanks to LeMuG (the french MySQL User Group) MySQL has had a nice set of presentations : Michael Widenius aka Monty ( Monty Program Ab ) presented "MariaDB, the future of MySQL". Johannes Schluter (MySQL connectors dev team + release manager of PHP 5.3) has presented "PHP and MySQL - A good match" This was the closing presentation for the 2 days but audience stayed to hear about the nice functionalities of the mysqlnd driver. A lot of interest for the new features (some experimental) : persistent connections, performance statistics, asynchronous request, client side cache, streams + filter, statistics collection, PDO + mysqlnd good match.
Showing entries 1 to 20 of 18310 Next 20 Older Entries

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