ganapathichidambaram

S No	Parts	Size ( Bytes )	Description
1	Boot Loader	446	Boot loader to load the kernel into the memory to the start the operating system

ganapathichidambaram

-- SQL : PostgreSQL
-- tablename - Name of the table which we want to alter the column 
-- columnname - Name of the columnn which we want to change to varchar from other datatype.
ALTER TABLE 
    tablename
    ALTER COLUMN
        columnname type varchar using columnname::varchar;

ganapathichidambaram

-- SQL : Postgresql
-- Query : Kill all the active connection of particular database.
SELECT 
    pg_terminate_backend(pid) 
FROM 
    pg_stat_activity 
WHERE 
    pid <> pg_backend_pid()
    AND datname = 'dev'; -- dev- Database Name which connection needs to be terminate

ganapathichidambaram

#!/bin/sh 

  # store start date to a variable
  imeron=`date`

  echo "Import started: OK"
  dumpfile="/home/bob/bobiras.sql"

  ddl="set names utf8; "
  ddl="$ddl set global net_buffer_length=1000000;"

ganapathichidambaram

from airflow.hooks.postgres_hook import PostgresHook
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults


class PostgresOperator(BaseOperator):
    """
    Executes sql code in a specific Postgres database

ganapathichidambaram

from airflow.hooks.postgres_hook import PostgresHook
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
from datetime import datetime, timedelta
from os import environ
import csv


class DataSourceToCsvOperator(BaseOperator):
    """

ganapathichidambaram

#!/bin/sh

cat <<EOT > /etc/issue
***********************************************************************
* Access to this computer system is limited to authorised users only. *
* Unauthorised users may be subject to prosecution under the Crimes   *
*                       Act or State legislation                      *
*                                                                     *
*   Please note, ALL CUSTOMER DETAILS are confidential and must       *
*                          not be disclosed.                          *

ganapathichidambaram

 #
 # Set up the serial console
 #
 %post
 echo ":: Setting up Serial Console ::"  >> /root/post.log
 perl -p -i -e 's/^(default.*)$/$1\nserial --unit=0 --speed=9600 --data=8 --parity=no --stop=1\nterminal --timeout=5 serial console/' /boot/grub/grub.conf >> /root/post.log 2>&1
 perl -p -i -e 's/^(\s+kernel.*)$/$1 console=tty0 console=ttyS0,9600/' /boot/grub/grub.conf >> /root/post.log 2>&1
 echo "" >> /etc/inittab
 echo "# Run serial console on ttyS0" >> /etc/inittab
 echo "S1:2345:respawn:/sbin/agetty ttyS0 9600 vt100" >> /etc/inittab

ganapathichidambaram

# vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
# START pre-kvmhost-partitions
#

set \$(list-harddrives)
echo "\$@"
disk=( \$1 \$3 )
size=( \$2 \$4 )

ganapathichidambaram

Steps to Recover InnoDB Tables

1. Stop mysqld.

2. Backup /var/lib/mysql/ib* files for safety reason.

3. Add the following line into /etc/my.cnf:

   innodb_force_recovery = 1