Upgrading PostgreSQL

PostgreSQL 7 provides more enhancements than any earlier release. The major enhancements include the following:

Foreign keys are now available for PostgreSQL, except for partial-match foreign keys.
The optimizer has been greatly improved, providing better query plan selection and faster performance while using less memory.
The interactive psql terminal monitor has been upgraded with a variety of new features including variables, SQL interpolation, and customized prompting. See the psql manual for detailed information about these features.
PostgreSQL 7.0 supports the SQL92 join syntax (as inner joins only). Additionally, join, natural join, join/using, and join/on are now supported. Column correlation names are also available.

Before Upgrading

Before upgrading from PostgreSQL 6.5 or PostgreSQL 7.0 to PostgreSQL 7.2, follow these instructions.

IMPORTANT:

The internal data storage format will change with each new PostgreSQL release. Therefore, your data must be backed up before upgrading to PostgreSQL 7.1 and the data must be restored after finishing the upgrade.
Do not update the database during or after the regular system backup.
Edit the permissions in the file to prevent user access. Any data that is changed at this time will be lost. The permissions file is usually located in ~/usr/local/pgsql/data/pg_hba.conf (or equivalent).
Be sure to restore the normal permissions after the installation is finished.

To dump your database onto your Virtual Private Servers, connect to your Virtual Private Server via SSH prompt, as root and do the following.

Run this command:
```
% pg_dumpall > outputfile 
```
To preserve the OIDs (such as when using them as foreign keys), use the -o option when running pg_dumpall. Make sure that you use the pg_dumpall command from the version you are currently running. Do not use the PostgresSQL 7.0 or PostgresSQL 7.1 pg_dumpall command on older databases.
If you are installing the new version in the same location as the old one, shut down the old server just before you install the new files. To find the old server process ID, use the command that matches your Virtual Private Server O/S.
- FreeBSD
```
% ps ax | grep postmaster
```
- Solaris
```
% ps -ef | grep postmaster
```
To stop the process, locate the process ID and type this:
```
% kill PROCESS-ID
```
Continue by Installing PostgreSQL.