Tuesday, July 26, 2016

Oracle-XE Configuration failes.

I installed today Oracle XE on SUSE 11 and I got this error during configuration:


Database Configuration failed. Look into /u01/app/oracle/product/11.2.0/xe/config/log for details

In the files in /u01/app/oracle/product/11.2.0/xe/config/log

there were these errors:

ORA-00119: invalid specification for system parameter LOCAL_LISTENER
ORA-00130: invalid listener address '(ADDRESS=(PROTOCOL=TCP)(HOST=linux-jbzk.site)(PORT=1521))'



The problem was on my machine the hostname was not pingeable.

Solution:

Add your current hostname (output of echo $HOSTNAME) to your /etc/hosts file

For example if your hostname is linuxbox :


127.0.0.1    linuxbox


Then you can re-run the oracle configuration:

/etc/init.d/oracle-xe configure


Source
https://community.oracle.com/

The Most Difficult Program to Compute? Meet the Ackermann function

The Most Difficult Program to Compute?
Meet the Ackermann function. Fascinating subject :)

 A(x,y)={y+1   if x=0; A(x-1,1)   if y=0; A(x-1,A(x,y-1))   otherwise.

 by Computerphile 


 

Saturday, July 16, 2016

How to change bash prompt to red when you are root

To change your bash shell prompt to red when you became root,  do the following:

  • login as root
  • vi ~/.bashrc
  • add the this line:  export PS1='\[\e[31m\][root]\[\e[0m\] \W\$'
 That's it!

Monday, July 11, 2016

Useful resources for code Optimization (C/C++/Assembly)


Here some references I find useful when it comes to code optimizations in C++

  • A case for strlen (32 bit only!) :  Just to start with a basic example!
 http://strchr.nfshost.com/optimized_strlen_function 


Tuesday, July 5, 2016