PostgreSQL Real choice.

Source: Internet
Author: User
Tags interface joins mysql variables postgresql variable domain mysql database

[Abstract] There are many database systems, free software database PostgreSQL is a very complete feature of the Free software object---Relational database management system (ORDBMS), its many features are the predecessor of today's many commercial databases. When Linux systems are popular, the PostgreSQL database system is also an efficient and stable database system for your needs.

In recent more than a year, the popularity speed of Linux is speeding up, in each forum Linux plate discussion is also very hot, linux+apache+php+mysql combination makes MySQL database is very hot. In fact, there is a more powerful database PostgreSQL in the database field.

PostgreSQL is a very complex object-relational database management system (ORDBMS), and it is also the most powerful, richest and most complex free software database system at present. Some features are not even available in the commercial database.

The Berkeley (BSD) database research program has now evolved into an international development project and has a very wide range of users.

PostgreSQL can be said to be the most unique free database management system, even we can be said to be the most powerful free software database management system. In fact, PostgreSQL's features cover both sql-2/sql-92 and sql-3/sql-99, and first, it includes support that can be said to be the most abundant data type in the world, some of which can be said to be not even commercially available, such as IP types and geometric types. Secondly, PostgreSQL is a fully functional free software database, and for a long time, PostgreSQL is the only one that supports transactions, subqueries, multiple versions of parallel control systems, data integrity
Check for features such as the only one of the free software database management system. Only recently did inprise InterBase and SAP and other vendors open their proprietary software to free software before breaking the only one.

1, installation
Naturally, you have to install it before you want to start using PostgreSQL. PostgreSQL is probably already installed on your machine because it is included in the release of your operating system, or the system administrator has installed it. Linux systems such as Redhat, Turbolinux choose to install the database system when installed, the PostgreSQL has been installed, if so, you should be from the operating system documentation or your system administrator to obtain information on how to access PostgreSQL.
If you are not sure if PostgreSQL is installed, or if you are able to do your own experiments with it, then you can install it yourself. It's not difficult, and it's a good practice. PostgreSQL can be installed by any unprivileged user and does not require superuser (root) privileges.
If you are ready to install PostgreSQL yourself, please refer to the Administrator's Manual (here is a Chinese document) for information about the installation, and then return to this instruction manual after installation. Be sure to follow the information in the chapters on setting the appropriate environment variables as much as possible.

If your machine administrator doesn't set up the relevant parameters in the default way, you have a little extra work to do. For example, if the database server machine is a remote machine, you need to set the PGHOST environment variable to the name of the machine on the database server. Environment variable Pgport may also need to be set. Last resort: If you're trying to start an application and the application reports that you can't make a connection to the database, you should contact your database administrator immediately, and if you are the admin, then you need to refer to the documentation to ensure that your environment variables are set correctly.

2. Basic concept of System
Before we begin to explain, we should first understand the basic system of the PostgreSQL system. Understanding the interrelationships between PostgreSQL parts makes this section clearer.

In database terminology, PostgreSQL uses a client/server model. A PostgreSQL session consists of the following related processes (Programs):
A server process that manages database files, accepts joins from the client application and the database, and performs operations on the database on behalf of the client. The database server program is called postmaster.
Client (front-end) applications for users who need to perform database operations. Client applications may be of a variety in themselves: they can be a tool for a character interface, an application of a graphical interface, a Web server that displays a Web page by accessing a database, or a special database management tool. Some client applications are provided with the PostgreSQL release, but most are developed by the user.
As with typical client/server applications (c/S applications), these clients and servers can be on different hosts. They then join the communication over the TCP/IP network. You should keep in mind that files that can be accessed on the client computer may not be accessible on the database server machine (or accessed only with different file names).
The PostgreSQL server can process multiple concurrent requests from the client. Therefore, it initiates ("fork") a new process for each request. From this point on, the client and the new server process are no longer communicating through the initial interference of the postmaster process. As a result, postmaster is always running, waiting for joins, and the two clients and associated server processes are starting and stopping. (Of course, users are definitely not going to see these things.) We are here to talk about these mainly for completeness. )
3. Using Database

If you are interested, refer to the Chinese user's manual, it is too long to say. You have the experience of using the database, you can quickly enter the PostgreSQL world. You can download the usage manual here.

If you're not tempted, look at the following PostgreSQL users.
4, PostgreSQL of the user's situation

Affymetrix: (
A biotechnology research firm that provides art-grade research tools for the genetic research industry,
In their transcriptome project, use PostgreSQL to store those from high-density
GeneChip? The experiment of mass RNA expression generated in the sequence.
Afilias: (
A domain registration provider that currently manages the first expansion of new releases on the Internet. INFO.
It is a company based in Ireland that manages over 900,000 domain names and over 10 million
Records, which are stored in a database that is PostgreSQL to the back end.
This should be familiar, Basford, the world's largest chemical company, using PostgreSQL for their
The U.S. agricultural integration industry's E-commerce website stores data.
Cognitivity: (
Online learning providers that use PostgreSQL for their performance software and management software.
Journyx: (

The world-recognized provider of web-based time and overhead tracking has more than 1 million end users.
They use PostgreSQL for internal database operations on all their UNIX platforms.
(Linux, BSD, AIX, Solaris, and soon MacOS X).
Modern Royal Typewriter Company, their online ecommerce website, with everything.
PostgreSQL storage.
The American Chemical Society:
American chemical Community, (, the world's largest professional chemical organization,
With more than 165,000 members, and a daily visit of more than 12 million people
's website. Their publications archive stores all publications for 125 years (25 million
Page, more than 1T of data), with a PostgreSQL. (Currently known PostgreSQL
The largest database).
Japan's largest video show rental chain, with PostgreSQL stores them over several G,
Millions of records of data, as well as doing their business information database.
Oh, yes, and Cisco, we're here:
A search for PostgreSQL will know.


PostgreSQL Chinese website

China Linux Forum

China UNIX Forum Http://

Develop PostgreSQL with C + +

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