1146 Table does not exist
1054 column does not exist
1062 duplicate entry for primary key
1406 Data too long for column
1064 sql syntax error
1111 invalid use of group function
1366 incorrect integer value
1046 No database selected

First start ipython in cluster mode

ipcluster start -n 4

from IPython.parallel import Client
rc = Client()
v=rc.load_balanced_view()
@v.parallel(block=True)
def f(x): return 2*x
result = f.map(range(10))
print("Using a parallel function: ", result)

You may see this message if you have DEBUG = True in your Django settings file and you haven't configured any URLs.

django-admin.py startproject todo

python manage.py runserver localhost:8000

$$ If you plan to use a database, edit the DATABASES setting in todo/settings.py.
python manage.py startapp todoapp

$$ syncdb and flush are other 2 parameters accepted by manage.py

Here is following commands to clear unwanted stuff from the /tmp partition on the server?

tmpwatch –mtime –all 48 /tmp

The above command will remove all files and folders from the /tmp which have not been accessed in the last couple of days (24×2=48). You can modify the number of hours as required.

If you need to change your server clock to another timezone for e.g. (Indian Standard Time), you can do so by modifying the /etc/localtime file:

mv /etc/localtime /etc/localtime.bak

ln -s /usr/share/zoneinfo/Asia/Calcutta /etc/localtime

If you have root access to the server then open the file /etc/aliases in your favorite editor. Look for the section Person who should get root mail and make the change as required.

vim /etc/aliases

Person who should get root’s mail ##
root: info@unixserveradmin.com

Instead of the first five fields, you can use any one of eight special strings. It will not just save your time but it will improve readability.

Special string Meaning
@reboot ——> Run once, at startup.
@yearly ——> Run once a year, “0 0 1 1 ”.
@annually –> (same as @yearly)
@monthly —> Run once a month, “0 0 1 ”.
@weekly —–> Run once a week, “0 0 0″.
@daily ——–> Run once a day, “0 0 ”.
@midnight –> (same as @daily)
@hourly —–> Run once an hour, “0 ”.

For e.g. run ntpdate every hour:
@hourly /path/to/ntpdatevim /etc/ssh/sshd_config

I am not able to install latest version of Libre office. I get an error message for file LibreOffice_6.3.4_Win_x86.msi

LibreOffice 6.3.4.2 can not be installed on this Windows version. Windows 7 SP1 or newer is required.

The fix is easy. Download earlier version for e.g. 6.2 version file:
LibreOffice_6.2.0.1_Win_x64.msi

From:

downloadarchive.documentfoundation.org

This site is very slow and may take 10 or 20 times more time to download older version compared to the latest one!

If I try the 64 bit version file LibreOffice_6.3.4_Win_x64.msi then I get the processor error like this:

This installation package is not supported by this processor type. Contact your product vendor.

This is a sample shell script while loop

while read mydb
do
echo "time scp /home/backup/mysql/$mydb/ticket.txt.gz 1.2.3.4:/tmp/$mydb.txt.gz "
done << dblist
akolaII
akol
ako
dblist

And here is poor man's schema compare using good old diff command...

mysqldump nasik1 --no-data > nasik1.sql

mysqldump -h1.2.3.4 murtizapur --no-data > murtizapur.sql

diff murtizapur.sql nasik1.sql --side-by-side --suppress-common-lines | grep -v ENGINE | grep -v BTREE > to_study.txt

Or use one of the packages:

code.google.com

www.red-gate.com

www.devart.com