Cara Install PostgreSQL (8.4) diLinux Ubuntu

       Step 1: PostgreSQL (8.4)

Installing postgresql (8.4)

sudo apt-get install postgresql-8.4

Setting up the password for postgres’ postgres user

sudo -u postgres psql template1
ALTER USER postgres WITH PASSWORD 'your-password';
\q

Configure postgres’ authentication method :

sudo cp /etc/postgresql/8.4/main/pg_hba.conf /etc/postgresql/8.4/main/pg_hba.conf_bak
sudo nano /etc/postgresql/8.4/main/pg_hba.conf

Add the following at the bottom of the file

# TYPE  DATABASE    USER        IP-ADDRESS        IP-MASK           METHOD
host    all         all         127.0.0.1       255.255.255.0    password

Restart postgres:

sudo /etc/init.d/postgresql-8.4 restart

Install PostgreSQL on Ubuntu 8.04

Following up from my old guide to installing PostgreSQL (for Ubuntu 7.10), I thought i’d better do an update for the latest releases… :)

This quick walk-through are my notes for installing the PostgreSQL database server and the PgAdmin administration application on Ubuntu Linux, and also set up the server so it allows access to other PC’s on your network.

Before we move on, this guide was tested on the current release of Ubuntu Linux, (8.04 - Hardy Heron) and PostgreSQL 8.3, but it should also be applicable to older versions (of Ubuntu and PostgreSQL) and other Debian based distros.
Right for the basic installation, at the command-line, enter the following commands (or search for the listed packages in synaptic if you prefer that way of working):

sudo apt-get install postgresql postgresql-client postgresql-contrib
sudo apt-get install pgadmin3

This installs the database server/client, some extra utility scripts and the pgAdmin GUI application for working with the database.

Now we need to reset the password for the ‘postgres’ admin account for the server, so we can use this for all of the system administration tasks. Type the following at the command-line (substitute in the password you want to use for your administrator account):

sudo su postgres -c psql template1
template1=# ALTER USER postgres WITH PASSWORD 'password';
template1=# \q

That alters the password for within the database, now we need to do the same for the unix user ‘postgres’:

sudo passwd -d postgres
sudo su postgres -c passwd

Now enter the same password that you used previously.

Then, from here on in we can use both pgAdmin and command-line access (as the postgres user) to run the database server. But before you jump into pgAdmin we should set-up the PostgreSQL admin pack that enables better logging and monitoring within pgAdmin. Run the following at the command-line:

sudo su postgres -c psql < /usr/share/postgresql/8.3/contrib/adminpack.sql

Finally, we need to open up the server so that we can access and use it remotely - unless you only want to access the database on the local machine. To do this, first, we need to edit the postgresql.conf file:

sudo gedit /etc/postgresql/8.3/main/postgresql.conf

Now, to edit a couple of lines in the ‘Connections and Authentication’ section…

Change the line:

#listen_addresses = 'localhost'

to

listen_addresses = '*'

and also change the line:

#password_encryption = on

to

password_encryption = on

Then save the file and close gedit.

Now for the final step, we must define who can access the server. This is all done using the pg_hba.conf file. (The following advice can also be given to you - plus you don’t even need to figure out IP addresses and subnet masks - from the latest versions of pgAdmin (1.6.x). But it doesn’t hurt to know how things work).

sudo gedit /etc/postgresql/8.3/main/pg_hba.conf

Comment out, or delete the current contents of the file, then add this text to the bottom of the file:

# DO NOT DISABLE!
# If you change this first entry you will need to make sure that the
# database
# super user can access the database using some other method.
# Noninteractive
# access to all databases is required during automatic maintenance
# (autovacuum, daily cronjob, replication, and similar tasks).
#
# Database administrative login by UNIX sockets
local   all         postgres                          ident sameuser
# TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD

# "local" is for Unix domain socket connections only
local   all         all                               md5
# IPv4 local connections:
host    all         all         127.0.0.1/32          md5
# IPv6 local connections:
host    all         all         ::1/128               md5

# Connections for all PCs on the subnet
#
# TYPE DATABASE USER IP-ADDRESS IP-MASK METHOD
host    all         all         [ip address]          [subnet mask]  md5

and in the last line, add in your subnet mask (i.e. 255.255.255.0) and the IP address of the machine that you would like to access your server (i.e. 138.250.192.115). However, if you would like to enable access to a range of IP addresses, just substitute the last number for a zero and all machines within that range will be allowed access (i.e. 138.250.192.0 would allow all machines with an IP address 138.250.192.x to use the database server).

That’s it, now all you have to do is restart the server:

sudo /etc/init.d/postgresql-8.3 restart

And all should be working.

Ubuntu – Enable mod_rewrite in Apache server

July 6, 2008 ― mahmud ahsan
At first I should define, what is mod_rewrite?
mod_rewrite is a part of Apache server that can rewrite requested urls on the fly.
To enable mod_rewrite in Ubuntu, you just need to write this command in terminal

sudo a2enmod rewrite
After enabling mod_rewrite you can write .htaccess file for your web application.
So what is .htaccess?
.htaccess file provides a way to make configuration changes on a per directory basis. It is a file contains configuration directives is placed in a particular document directory and the directives apply to that directory and all subdirectories thereof.
Some example:
Nice looking URLs (no querying) with pagination:
Suppose your url is: domain.com/article.php?name=title&page=5You want to change: domain.com/articles/title/5/
Then write in .htaccess file:
RewriteRule ^articles/(A-Za-z0-9-]+)/([0-9]+)/?$ article.php?name=$1&page=$2 [L]
The rule is defined in regular expression. Here [L] means Last Rule. It’s called RewriteRule Flags.
Another example:
Suppose your site has permanently moved to a new domain.
RewriteCond %{HTTP_HOST} ^www.domain.com$ [NC]
RewriteRule  ^(.*)$ http://www.domain2.com/$1  [R=301, L]
Here [NC] means case insensitive and its called RewriteCond Flags. [R=301] means moved permanently. Its called redirection header code.