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Displaying posts with tag: Technology (reset)
Install MySQLdb module for Python

Update:

Commenter MarkR made a great point: if possible, use some packaging tools, to try to maintain proper dependencies, to the extent that is possible. Install from the source should be Plan B. So, try yum install MySQL-python first.

This is mostly for my own future reference. It’ll be icing on the cake if it helps you!

This is geared for CentOS or Red Hat. Use apt-get or other packaging tools for different flavours of Linux.

1. Get Python module setuptools called easy_install. I love easy_install, by the way, sort of like CPAN for Perl modules;
2. To install MySQLdb package, you would think easy_install MySQLdb would do. But that is not the case. I hope the developer would fix that. Instead, you need:

easy_install MySQL-python

3. If you have build errors, you may need:
yum install python-devel or yum …

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How to make MySQL cool again

Jonathan Levin has an excellent blog post titled How to make MySQL cool again. It is almost word for word something I've wanted to write for a long time. Now I don't need to, thanks Jonathan.

Once again Blogger failed to post my comments to his site, so I will make some comments as a new post of my own instead. Jonathan actually lists things that exist already but isn't getting used enough. My list contains also a few things that I don't know if they exist or not.

Hi Jonathan

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SELinux and “failed to map segment from shared object” error

I am reading and following examples in MySQL 5.1 Plugin Development. After compiling and moving a .so file (think DLL or Assembly file in Windows) into MySQL plugin directory, I got this message when I tried to create a UDF (User Defined Function):

mysql> create function udf_staticexample returns integer soname 'udf_staticexample.so';
ERROR 1126 (HY000): Can't open shared library 'udf_staticexample.so' (errno: 0 /usr/lib/mysql/plugin/udf_staticexample.so: failed to map segment from shared object: Permission denied)

This is caused by the fact that the .so shared object file is not in the right SELinux security context:

[root@asusfedora plugin]# ll -Z
lrwxrwxrwx. root root …
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Data generation with TPC-H’s dbgen for load testing

2011-06-26 update:

I am not sure if there are any changes in the latest make and gcc packages. Anyway, I noticed when run make, I encountered the message below:

make: g: Command not found
make: [qgen] Error 127 (ignored)

To fix this, find where gcc is at, then created a symbolic link g that points to gcc. All is well afterwards:
[root@ip-10-245-209-196 dbgen]# which gcc
/usr/bin/gcc
[root@ip-10-245-209-196 dbgen]# cd /usr/bin/
[root@ip-10-245-209-196 bin]# ln -s gcc g

End update
Recently I found myself doing some data loading benchmark testing with table partition. Data loading and storing for BI/DW/DSS stuff almost always involves data partitioning. SQL Server partition has a nice feature called partition switch, where you can swap data in and out of a partitioned table. …

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Seeking input on updating sample my.cnf files

The sample my-small.cnf, my-medium.cnf, my-large.cnf, my-huge.cnf, and my-innodb-heavy-4G.cnf files from MariaDB and Percona (I didn’t bother checking Oracle’s distro) were from the dinosaur age, with comment like this for my-huge.cnf:

This is for a large system with memory of 1G-2G where the system runs mainly MySQL.

So I suggested some updating is needed on IRC and mailing lists. After getting a kick in the pants from the always affable Kurt von Finck (I thought “kick in the pants” is a pretty good rendition of “遣将不如激将”, for those who followed our exchanges in mailing lists), I decided to take this upon myself.

It’s actually not hard to update this. I believe just 6 files in total, at most, need to be touched under the support-files directory inside the trunk: my-small.cnf.sh, my-medium.cnf.sh, my-large.cnf.sh, my-huge.cnf.sh, my-innodb-heavy-4G.cnf.sh, and Makefile. Please let me know if my …

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Q&A with Stephen Baker of "Final Jeopardy"

IBM's Watson natural language Question & Answer system made headlines recently with its primetime debut on Jeopardy.  Despite a few embarassing answers, Watson trounced top Jeopardy players Brad Rutter and Ken Jennings.  Watson is built from 90 IBM Power 750 IBM Linux servers with 16 terabytes of memory providing 80 Teraflops of processing power.  Watson is perhaps the most famous "Big Data" systems out there.  Watson's knowledge base consists of 200 million pages of text data that is pre-processed using  …

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SSDs and their impact on database servers

Vadim Tkachenko published interesting benchmark results with PCI-E based SSDs here. I recently got a chance to benchmark FusionIO’s 320 GB PCI-E drive. It was really impressive. My results, done on Windows with sqlio, are consistent (not identical, of course, but in the same ballpark) with what Vadim reported in that blog post, done with sysbench on Linux.

sqlio is a popular IO throughput testing tool from Microsoft. I didn’t get to test the throughput when the SSD is close to full. The key takeaways that I learned from my testing are:

1. I can confirm that there is no difference between random and sequential IO, contrary to the traditional spindle based hard disks;

2. Read is significantly faster than write. Reads and writes with 64 threads can achieve around 1.4 GB/S and 400 MB/S …

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Behind the Scenes at a Venture Capital Firm



Last fall, before I joined Zendesk, I took a role as an Executive-in-Residence at Scale Venture Partners. A lot of people asked me about this, so I've written an article at GigaOm that describes my thought process and what I ended up working on.

While there are as many variations on the EIR position as there are venture firms, there are two flavors, generally speaking: Entrepreneur-in-Residence and Executive-in-Residence. Most firms have some experience with Entrepreneur-in-Residence programs. Essentially, they give office space, coffee and food to a proven entrepreneur so he or she can spend a few months researching or prototyping a new …

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Moving a LAMP site

I’ve done this in the past, but thought this time I’ve got to take notes. It can be used as a crude check list in the future. Don’t underestimate the power of a practical, down-to-earth check list! Perhaps documents like this should be kept in a wiki page, for easy updating to avoid being stale, a proeblem with blog entries, it seems.

P in LAMP here stands for php, not Python or Perl. L is CentOS (I used CentOS 5.5) or Red Hat Linux. I am not covering moving all databases in a MySQL instance, just a select few or just one.

I’d appreciate your comments or suggestions.

Software install and configuration
MySQL:
MariaDB or Percona.

MariaDB can be had here.

For Percona server and client tools, it’s best to have direct access to Percona’s repository:

yum install gpg
rpm -Uhv …
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Packages needed for building MySQL/MariaDb/Percona

From a stock/standard/typical/desktop install of Linux, it seems these are required in order to build MySQL/MariaDb/Percona forks:

gcc
gcc-c++
automake
libtool
bison
ncurses (Thanks Justin!)

Do apt-get, yum, rpm, emerge, or whatever to get them before doing configure, make and such. I am missing one, and I think it has “curse” or something like that in its name. Will update this post when I find that out.

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