Re: Is is worth organising a

["Shridhar Daithankar" <shridhar_daithankar(at)persistent(dot)co(dot)in>]

On 31 Oct 2002 at 15:21, Nicolas Pettiaux - AEL wrote:

> Putting action next to verbs , I have already created
> 
> http://wiki.ael.be/index.php/PostgresqlAdvocacy
> 
> inside the wiki setup by the AEL, the Belgian association for the 
> promotion of human rights in the information society, in fact working 
> very much at the promotion of free software in Belgium.

I have added couple of suggestion in particular with LUGs. I can forward these 
news letter to at least two LUGs I have subscribed to. That should cover some 
1500 subscribers all in all. They will get to read this at their door steps.

I am also attaching a psotgresql 101 that I was planning to write for a long 
time. It's just a two page document that gets up a person running in 5  
minutes. I remember searching thr. docs for couple fo days to get everything 
together. I hope this will allow people to get a speedy head start.

I don't know if it should go to advocacy or doc. But either place looks equally 
good to me. Make a flyer out of this 101 and hand over to potential users..;-)

Let me know your comments.

Bye
 Shridhar

--
May's Law:	The quality of correlation is inversly proportional to the density	
of control.  (The fewer the data points, the smoother the curves.)


Postgresql 101

This is to help people start with postgresql in matter of minutes. 

Following are some simple assumptions made here.

* The OS is unix like
* Postgresql is already installed on the system


Starting postgresql from scratch

1) Log in as any OS user. This user will be database super user and it 
can not be OS user root. Typically this user is called as 'postgres' or 'pgsql'. 
But it can be any other user as well

2) Export environment variable PGDATA to a directory where database is to be located and
call initdb to create initial database template.

e.g.
$ export PGDATA=/mnt1/dbs/postgresql
$ initdb

This will create a template database in /mnt1/dbs/postgresql. For all practical purposes, 
consider this directory opeque unless you know what you are doing.

When initdb is finished, it will tell you how to start postgresql server as last part of 
initdb mesages

--------------------------
Success. You can now start the database server using:

    /usr/bin/postmaster -D /mnt1/dbs/postgresql
or
    /usr/bin/pg_ctl -D /mnt1/dbs/postgresql -l logfile start
--------------------------

So you should now start the database serevr as indicated by last message. Using pg_ctl is 
the simplest way of doing that.


4) Create a database to start with.

$ createdb test
CREATE DATABASE
$

5) Start using it with postgresql terminal sql client.

$psql test
Welcome to psql, the PostgreSQL interactive terminal.

Type:  \copyright for distribution terms
       \h for help with SQL commands
       \? for help on internal slash commands
       \g or terminate with semicolon to execute query
       \q to quit

test=#

At this point, you can use all the commands shown in postgresql manual. Enjoy!


Some useful tips

1) Shutting down the database

* Log in as database super user. It's the OS user who ran initdb etc. in above steps
* Use pg_ctl to stop the database

$ pg_ctl -D mnt1/dbs/postgresql stop

2) Start postgresql with network option.

Postgresql by default does not listen on network. To make it do so, you need to pass '-i' option to it. 
The pg_ctl command will be modified to look like

$ /usr/bin/pg_ctl -D /mnt1/dbs/postgresql -l logfile -oi start

3)Tuning postgresql

Many paramters that postgresql uses can be modified using configuration file $PGDATA/postgresql.conf
The configuration file is well documented. Read the administrators guide as well.

If you are looking for any heavy duty work, keep in mind that postgresql defaults are very conservative 
and are not meant for any heavy duty work. Please tune the system before you put load.

4) Users in postgresql

You can create databases in postgresql and users. But unlike some other RDBMS, users in postgresql are 
global i.e. same username/password can be used to connect to any database in system. Rights granted to 
any users are of course can be tuned but there is nothing like a user in a particular database