PostgreSQL Cheat Sheet

CREATE DATABASE

CREATE DATABASE dbName;

CREATE TABLE (with auto numbering integer id)

CREATE TABLE tableName (
 id serial PRIMARY KEY,
 name varchar(50) UNIQUE NOT NULL,
 dateCreated timestamp DEFAULT current_timestamp
);

Add a primary key

ALTER TABLE tableName ADD PRIMARY KEY (id);

Create an INDEX

CREATE UNIQUE INDEX indexName ON tableName (columnNames);

Required operating system and packages

First of all install centos 5.2 with minimal packages and no gui required.
Packages required for setting up linux server as loadbalancer are as below.
heartbeat-2.1.4-4.1.i386.rpm
heartbeat-devel-2.1.4-4.1.i386.rpm
heartbeat-ldirectord-2.1.4-4.1.i386.rpm
heartbeat-pils-2.1.4-4.1.i386.rpm
heartbeat-stonith-2.1.4-4.1.i386.rpm
libnet-1.1.2.1-2.1.i386.rpm
perl-MailTools-1.76-1.el5.rf.noarch.rpm

There might me some more package dependencies but it can be resolved by installing those packages from cd.

Hi,
Many times we need to install packages which are available only in form of source code. Or sometimes we need to install couple of different versions of packages on same server... what ever reason it may be, We can achieve this by compiling packages.

Here in this article I will just show you quick steps how to compile berkeley db and openldap.

First of all we need to download Berkeley DB and OpenLDAP. use following links to download latest stable versions.

To download Berkeley DB
http://www.oracle.com/technology/software/products/berkeley-db/index.htm...

Today I wanted to change date and time on one of my server quickly from command line. I am aware with command line options but every time I want to do it, I need to read man page or help to get perfect combination so i decided to write this small how to which can help me and you every time we want to change date and time in linux from command line.

Remember, CLI (command line interface) is most powerful for users / administrators like us.

To change system date in linux, type:-

#date MMDDhhmmYYYY.ss

Hi all, In this article you will know some very very basic commands about postgresql. When i started learning postgresql, I found bit strange when "show databases", "show tables", and "show columns" command did not work. I was using mysql and I am still using mysql but it is just matter of learning one more database as postgresql started becomming popular now. So.. If you have question in your mind how to list databases, tables and colums in postgresql database then I have answer for you.

First of all to connect to postgresql you need to use :

1. Postgresql: show tables, show databases, show columns

Hi all, hope you are enjoying series of articles published on this website for free.. totally free.

In this article you will learn how to setup redundant NFS servers using DRBD (Distributed-Replicated-Block-Devices) Technology. Complete step-by-step procedure is listed below. It works for me so hopefully it will work for your also. No gurantees are given.

1. Two servers with similar storage disk (harddrive) setup (To create a redundant nfs server)
2. One client system/server where the nfs share will be mounted.
3. Static IPs for all servers.

Hi all, Many time we came across systems where root (/) filesystem is mounted read only (ro) and we need to edit some configuration files but we can not until we remount it with read write (rw) priveleges.

Say for example you changed some configuration in /etc/fstab file and next time when you reboot system, it is not able to find /boot or / partitions references listed in fstab file. You are confident and knowing that your data is there on disk but system is not able to mount it correctly and refusing to boot.