Monday, January 6, 2014

Cyclical recursion in MySQL that can be used for DFS or BFS

Just wanted to share these blogs,

http://guilhembichot.blogspot.com/2013/11/with-recursive-and-mysql.html
http://blogs.msdn.com/b/sqlazure/archive/2010/07/01/10033575.aspx
http://ilyasterin.com/blog/2014/01/cyclical-dependency-detection-in-the-database.html

Cheers ;-)

Saturday, October 19, 2013

Ugrading MySQL (Percona) to the causing: dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)

I have encountered this when I was upgrading my packages and one of them is Percona Server.

Then I encountered this strange error below,

(Reading database ... 82838 files and directories currently installed.)Preparing to replace libmysqlclient18-dev 1:5.5.33-rel31.1-566.precise (using .../libmysqlclient18-dev_1%3a5.5.33-rel31.1-568.precise_amd64.deb) ...Unpacking replacement libmysqlclient18-dev ...dpkg: error processing /var/cache/apt/archives/libmysqlclient18-dev_1%3a5.5.33-rel31.1-568.precise_amd64.deb (--unpack): trying to overwrite '/usr/lib/libmysqlservices.a', which is also in package libmysqlclient-dev 1:5.5.33-rel31.1-566.precisedpkg-deb: error: subprocess paste was killed by signal (Broken pipe)Errors were encountered while processing: /var/cache/apt/archives/libmysqlclient18-dev_1%3a5.5.33-rel31.1-568.precise_amd64.debE: Sub-process /usr/bin/dpkg returned an error code (1)

So my fix to that is remove  this package "libmysqlclient18*".

I'm in Ubuntu 12.10 on this environment, so I fixed it by,

root@ubuntu-toytoygogie:/var/log# dpkg -l|grep libmysqlclient18ii  libmysqlclient18                  1:5.5.33-rel31.1-566.precise                        Percona Server database client libraryii  libmysqlclient18-dev              1:5.5.33-rel31.1-566.precise                        Percona Server database development files - empty transitional

then remove it by,

root@ubuntu-toytoygogie:/var/log# apt-get remove libmysqlclient18* 


Then re-install Percona Server 5.6 to the latest one by,

root@ubuntu-toytoygogie:/var/log# apt-get install percona-server-server-5.6

 Hope that helps.

Ubuntu: locale: Cannot set LC_CTYPE to default locale: No such file or directory

For some reason, It seems that LC_CTYPE is not declared and can't use fallback to use LC_ALL value.

So my very easy fix on this is to declare or define a global shell environment variable in my /etc/default/locale.

Here's what my /etc/default/locale contains,


toytoy@ubuntu-toytoygogie:~$ cat /etc/default/locale
LANG="en_US.UTF-8"
LC_ALL=en_US.UTF-8

Hope that helps.

Why Ubuntu in VM cannot connect to the internet

Usually, I got this problem when I start Ubuntu and I cannot connect to the internet.

So my fix is just pretty simple, though either might work in your end or not.

1. update your date
2. restart service on /etc/rc.d/networking

So in my case, how did I fix it is by

$ service ntp stop$ ntpdate 10.0.1.19$ service networking restart$ service ntp start
So where did I have this 10.0.1.19? This is my other VM also, act as a server which interacts through the ntp socket and updates from the 10.0.1.19 server's time. If you don't have other VM, I'm not sure with this, just try to update your date to the recent date you have.

Afterwads, just run

$ /sbin/dhclient eth0

and hope everything will work into your end.

Monday, September 2, 2013

Benchmarks result using different storage technologies: FusionIO, SSD, RAID

I just wanted to share these great benchmark results for your guide,


http://www.ntlug.org/Articles/DiskBenchmarks


http://www.mysqlperformanceblog.com/2009/05/01/raid-vs-ssd-vs-fusionio/

Monday, August 26, 2013

MySQL: learning how to recover your InnoDB from corruption

This is wonderful post to learn how to recover your data from Peter Zaitsev,

http://www.mysqlperformanceblog.com/2008/07/04/recovering-innodb-table-corruption/


This means that in every BTREE context, there's always a page and by using BTREE data structure, you have records stored in there as part of the page and that means you can recover your data from its tablespace.

Sunday, August 25, 2013

MySQL: Like this blog from Miguel. A must read

In case you're experiencing your ibdata1 is getting bigger, read this wonderful post by my colleague Miguel at Percona.

http://www.mysqlperformanceblog.com/2013/08/20/why-is-the-ibdata1-file-continuously-growing-in-mysql/