Postgres SQL

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Revision as of 16:45, 10 November 2007 by WikiSysOp (talk | contribs) (Configuration files)

General

This guide is tested on ubuntu feisty with postgresql 8.2. It should work for former and future versions of both too.

General documentation you will find here:

You should read this in advance to make shure the concepts behind postgresql configuration, startup and security (e.g. 'roles).

User Management

General Dokumentation

Ubuntu Feisty, Gutsy

Installation

Install postgresql

sudo apt-get install postgresql-8.2 postgresql-client-8.2

For administration we install pgadmin3

sudo apt-get install pgadmin3 pgadmin3-data

Set database admin account

Alter the password for the standard postgres user account (as root)

sudo su
postgres -c psql template1

Inside the database:

template1=# ALTER USER postgres WITH PASSWORD 'new_password';
template1=# \q

/etc/postgresql/8.2/main/postgresql.conf

Assure that the server is accessible on localhost

sudo gedit /etc/postgresql/8.2/main/postgresql.conf
listen_addresses = 'localhost'
password_encryption = on

/etc/postgresql/8.2/main/pg_hba.conf

Security and server settings. If you like to use the server in a network you have to pay attention to three points:

  1. Add the server ip to the listen adress
  2. Allow special clients to connect
  3. Think about using ssl, if you connect through the internet
sudo gedit /etc/postgresql/8.2/main/pg_hba.conf
# - Connection Settings -
# what IP address(es) to listen on; 
# comma-separated list of addresses;
listen_addresses = 'localhost,server_IP' 
 
# Allow any user on the local system to connect to any database under
# any user name using Unix-domain sockets (the default for local
# connections).
#
# Database administrative login by UNIX sockets
local all all trust

# 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
# e.g. host all all 192.168.0.0/24 md5
# e.g. host all all 192.168.0.10 255.255.255.0 md5
host all all [ip address] [subnet mask] md5

Restart postgresql

sudo /etc/init.d/postgresql-8.2 restart

SuSE 10.1, 10.3

First I have to mention that it is almost impossible to get a howto to install postgresql on SuSE. I really don't now why. Finding an according howto for ubuntu was a matter of minutes. Not even a search at support database of SuSE got ANY result. This is really poor.

Installation

Prior 10.3

  • Via YaST and the previously mentioned packman repository

Administration

Pgadmin III

You will find them in the guru repositories:

  • prior to opensuse 10.3
    • via YaST and the previously mentioned packman repository

Post Installation

Start the server for the first time:

rcpostgresql start

Login

su postgres -c psql postgres
postgres=# 

Configuration files

  • all configuration files are in
cd /usr/share/postgresql

You have to copy the /usr/share/postgresql/*.sample files to .conf and edit them according to your needs.

cp pg_hba.conf.sample pg_hba.conf
cp postgresql.conf.sample postgresql.conf


I edited the pg_hba.conf (the security settings) according to a debian/ubuntu setup. Delete everything in the original file and put in this content:

# 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                               ident sameuser
# IPv4 local connections:
host    all         all         127.0.0.1/32          md5
# IPv6 local connections:
host    all         all         ::1/128               md5

# Allow Connections for certain PCs on a subnet.
# Alter this according to your own hosts/network configuration.
#
# TYPE DATABASE USER IP-ADDRESS IP-MASK METHOD
host    all     all     192.168.0.200   255.255.255.0    md5
host    all     all     192.168.0.201   255.255.255.0    md5
host    all     all     192.168.0.203   255.255.255.0    md5

For the postgres server settings file postgresql.conf alter the file according to the following settings:

[...]
data_directory = '/usr/share/postgresql/'
hba_file = 'ConfigDir/pg_hba.conf'
ident_file = 'ConfigDir/pg_ident.conf'

listen_addresses = 'localhost,192.168.0.1'   # CHANGE TO YOUR IP
port = 5432
max_connections = 100
ssl = on
password_encryption = on
shared_buffers = 24MB

stats_row_level = on
autovacuum = on
default_transaction_read_only = off

datestyle = 'iso, dmy'
lc_messages = 'de_DE.UTF-8'
lc_monetary = 'de_DE.UTF-8'
lc_numeric = 'de_DE.UTF-8'
lc_time = 'de_DE.UTF-8'

Administration with Pgadmin III

Pgadmin helps you with almost all administration tasks to manage your postgresql databases. From managing user accounts (roles), creating tables, schemes, constraints (e.g. primary keys) to an extended sql editor.

Initial registration with pgAdminIII

To be able to manage your database with pgadmin you have to configure it for the specific server:

Working with pgAdminIII

Queries with pgadminIII

A very good tool for working with the database is the integrated sql query editor of pgadmin. Select the database you want to work with, then you can choose the query tool from the menu.

PostgreSQL queries are case sensitive. So if you specified Uppercase names for columns you have to use them exactly and in quotes. It might be necessary to add the schemata name postfixed by a dot to get a proper query:

select "Prename" from myscheme."Client";

Press <F5> to start the query.

You can easily save the queries in a file for later reuse.

Backup and restore with pgadminIII

PgadminIII makes it easy to backup your database withor without all the data. Just highlite the database you like to backup and choose the backup option from the main menu.

ODBC, Postgres and Openoffice

According to PostgreSQL-Datenbanken in OpenOffice.org 2.0 unter Linux.

Ubuntu Gutsy (7.10)

Openoffice <-> ODBC

For connection between openoffice and odebc:

apt-cache search odbc | grep unix
   unixodbc - ODBC tools libraries
   unixodbc-bin - Graphical tools for ODBC management and browsing

apt-get install unixodbc unixodbc-bin

With the command ODBCConfig you can manage the configuration files (part of the package unixodbc-bin). Start it as superuser with gksu or use it to manage your local database configuration files - stored in your home directory.

But for nowe, we will - later - edit the configuration files by ourself.

ODBC <-> Postgresql

For connection between the odbc layer and the database:

apt-cache search odbc
   odbc-postgresql - ODBC driver for PostgreSQL

apt-get install odbc-postgresql

Configuration files

Ubuntu installs its odbc libraries in /usr/lib/odbc. There are two versions of the postgres odbc driver: an ascii version (psqlodbca.so) and a unicode version (psqlodbcw.so). We are using the latter.

vim /etc/odbcinst.ini
[PostgreSQL]
Description = PostgreSQL ODBC Driver
Driver = /usr/lib/odbc/psqlodbcw.so
Setup = /usr/lib/odbc/libodbcpsqlS.so

For system wide database location you have to edit the /etc/odbc.ini file.

There is a section Driver. You have to insert exactly the same name as defined in the odbcinst.ini between the braces, e.g. use PostgreSQL, if your odbcinst.ini is defined as [PostgreSQL]:

vim /etc/odbc.ini
[pgTestDBSource]
Description = PostgreSQL Test Database
Driver = PostgreSQL
Servername = localhost
Database = pgtest
Port = 5432
ReadOnly = No

Establish connection

If you like to connect to an database via openoffice you should use a string like:

odbc://servername/databasename

Don't forget to allow connections in /etc/postgresql/8.2/main/pg_hba.conf (see above) to your database server!

The rest is really self explanatory within the openoffice database assistant ;)