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Displaying posts with tag: database (reset)
HP P800 Smart Array Performance

I had a chance to test HP Smart Array P800 SAS RAID controller with HP Proliant DL380 G5 server with the following configurations:

  • Dual Quad Core 2.5Ghz
  • 32-GB RAM
  • P800 Smart array with SAS interface
    • 25 disks, 10K RPM, 146G each
    • 512M cache
    • Battery backed

Here is the sysbench fileio random write performance numbers  for RAID-10 with the following …

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New version of employees test DB



The Employees Test database has been updated. There was a subtle bug in the data. One employee was assigned to two departments with the same start and end date. And one of the sample procedures fell into the trap of assuming that the data was clean, thus reporting incorrect statistics.
Now the bug is fixed, the test suite is updated, and I can wait for the next bug report.
New England Database Society Meeting

I am passing this along — I am not sure if most folks reading this can make it, as it is last-minute and in the Boston area, but I figured I’d let people know that the New England Database Society exists. It’s free, sponsored by Sun (and has been for years, long before Sun bought MySQL), and is hosted by my college database professor, Mitch Cherniack. (To that end, I should probably make sure to promote the Boston User Group here more often! I keep forgetting…)

You can find information on how to be a part of the mailing list at http://www.cs.brown.edu/sites/neds/

The next New England Database Society will be held on Friday, March 27 and the speaker is Christian Jensen of Aalborg University.

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[N]ew [E]ngland [D]atabase …

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MySQL 5.1 Mix Of Handlers In Partitions

One good feature in MySQL 5.1 is the support of partitions which is built into the MySQL server. Lot of applications that I noticed use their own partition schemes by splitting the large table data to multiple tables on a desired key and wrapper table or application logic that identifies what table to use.

Here comes MySQL to rescue all those applications to push the partition logic to MySQL server itself without needing a application specific logic; which maintains partitions underneath the covers (each partition is a sub-table) on a single large table as shown below:

The partition key is specific to table and/or application. If the partition key is account_id or site_id or anything that takes both active writes and reads; …

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SSD Peformance With Different File Systems

I just tested the new Intel X25-E Solid State Drive on RHEL-4 64-bit with three file systems (ext2, ext3 and XFS) using the sysbench fileio test.

The test is done to gauge the performance of SSD as a temporary solution to act as tmpdir for MySQL server where result set temporary files are heavily created.

Here is the test results:

Overall, ext2 yields much better results on random IO along with sequential read. All file systems are mounted with noatime and XFS is mounted with noatime + nobarrier

So, even if one …

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All about Puppet storeconfigs

Since a long time people (including me) complained that storeconfigs was a real resource hog. Unfortunately for us, this option is so cool and useful.

What’s storeconfigs

Storeconfigs is a puppetmasterd option that stores the nodes actual configuration to a database. It does this by comparing the result of the last compilation against what is actually in the database, resource per resource, then parameter per parameter, and so on.

The actual implementation is based on Rails’ Active Record, which is a great way to abstract the gory details of the database, and prototype code easily …

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I’m looking for sharding problems

Do you want a SPOCK tee shirt?  Read on:

I’m going to give a talk on Spockproxy (a sharding / connection pooling only version of MySQL proxy) at the MySQL conference and as I prepare I’m looking to give my talk broad appeal and try to address all kinds of problems folks might have sharding their databases.

So I’m throwing this question out to the MySQL community – Have you looked into sharding your database(s)?  Did you come up against problems that were difficult to solve? Please take a moment and let me know about them.  I’d like to address how to fix them with Spockproxy.  Even if you’ve solved these issues already or have no intension of using Spockproxy your problems could be interesting to others; add your sharding problem(s) in the comment below and look for me  …

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Swapping Column Values in MySQL

Today I had to swap 2 columns in one of my MySQL tables. The task, which seems easily accomplishable by a temp variable, proved to be a bit harder to complete. But only just a bit.

Here are my findings:

  1. The

    UPDATE swap_test SET x=y, y=x;

    approach doesn't work, as it'll just set both values to y.

    PostgreSQL seems to handle this query differently, as it apparently uses the old values throughout the whole query. [Reference]
  2. Here's a method that uses a temporary variable. Thanks to Antony from the comments for the "IS NOT NULL" tweak. Without it, the query works unpredictably. See the table schema at the end of the post. This method doesn't swap the values if one of them is NULL. Use method #3 that doesn't have this limitation. …

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MySQL University: Developing MySQL on Solaris

This Thursday (February 19th, 14:00 UTC), MC Brown & Trond Norbye will give a MySQL University session on Developing MySQL on Solaris. MC works on the MySQL Documentation Team and has been involved with quite a few Solaris things, for example porting MySQL to openSolaris. Trond has been involved with many things, including openSolaris, as you can see from his blog.

For MySQL University sessions, point your browser to this page. You need a browser with a working Flash plugin. You may register for a Dimdim account, but you don't have to. (Dimdim is the conferencing system we're using for MySQL University sessions. It …

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Tokyo Cabinet in MySQL?

I read Tokyo Cabinet: Beyond Key-Value Store today from one of the news sites, and it reminded me of Brian’s hack on Tokyo Cabinet == Tokyo Engine. Looking at TokyoEngine in Brian’s Mercurial repository, there have been no updates in over a year. Is anyone planning on taking up development of this? Tokyo Cabinet looks really interesting, and Brian has already started the enabling of making it a MySQL engine.

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