Postgresql – How to import the data of postgres 8.x to postgres 9.x

postgresql

My OS is windows 7 x64. I was use postgres 8.4, and all databases are in postgres/8.4/data. Yesterday, I reinstalled my os system, but I found I can't install postgres 8.4 anymore (there is always an error when installing), so I installed postgres 9.1.

But I don't know how to reuse the data of postgres 8.x. I tried to copy the data from postgres/8.4/data to postgres/9.1/data, but the postgres service won't start.

Is there any way to reuse that. Since I have a lot of data in postgres/8.4/data, I can't loose them.

Best Answer

What you need is a dump / restore. However, for this to work, you need the old PostgreSQL 8.4 server running. The new version 9.1 is not binary compatible and cannot use the files in postgres/8.4/data directly.

If you have no backup and cannot run PostgreSQL 8.4 on your machine any more, you are out of luck. Why is it that you cannot install PostgreSQL 8.4 any more? You'll have to, if you want your data.

On a side note:
It is recommended that you use the pg_dump and pg_dumpall programs from the newer version of PostgreSQL, to take advantage of any enhancements that may have been made in these programs.

Related Solutions

Postgresql – How to install pgcrypto in PostgreSQL 8.4

For newer version of PG, check out the answer below by Dustin Kirkland

It's an external module for Postgres. You should install the postgresql-contrib-8.4 (or your pg version) package via apt:

apt-get install postgresql-contrib-8.4

Then you find the sql install file somewhere in the /usr/share/postgresql folder, and you'll need to run pgcryto.sql on the database.

psql -d <database> -f /usr/share/postgresql/8.4/contrib/pgcrypto.sql

Or,

$ cd /usr/share/postgresql/8.4/contrib
$ psql -d <database>
    psql (8.4.8)
    Type "help" for help.

    database=# \i pgcrypto.sql

PostgreSQL on Ubuntu – Using conf files for recovery

The recovery.conf file needs to go into the data directory (/var/lib/postgresql/...). The other configuration files can stay where they are (/etc/postgresql/...). Then a normal restart should do what you want.

Best Answer

Related Solutions

Postgresql – How to install pgcrypto in PostgreSQL 8.4

PostgreSQL on Ubuntu – Using conf files for recovery

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