Re: Postgres DB Migration from 8.3 to 9.1

[Steve Crawford <scrawford@xxxxxxxxxxxxxxxxxxxx>]

On 10/12/2012 08:05 AM, Amitabh Kant wrote:

On Fri, Oct 12, 2012 at 7:45 AM, Vishalakshi Navaneethakrishnan <nvishalakshi@xxxxxxxxxx> wrote:

Hi Friends,

We have our production environment database server in Postgres 8.3 version. we have planned to upgrade to lastest version 9.1. Dump from 8.3  and restore in Postgres 9.1 takes more than 5 hours. Any other quick method to upgrade from 8.3 to 9.1. We need to reduce our downtime  below 1 hour. Any Possibilities..?

Thanks in Advance.

--
Best Regards,
Vishalakshi.N

Try using the -j <number-of-jobs> option to speed up restore process. See http://www.postgresql.org/docs/9.1/static/app-pgrestore.html . Not  sure though whether it will bring it up within your range. 

Amitabh

Note that one issue with the -j option is that it requires the input be a regular file rather than a pipe so you have to wait until you have a complete dump stored on-disk somewhere before you can start the restore. This delay may offset, eliminate or overshadow any benefit from the parallel-restore speedup.

Pg_upgrade does support upgrades from 8.3: http://www.postgresql.org/docs/current/static/pgupgrade.html but you will need to set up a dev-system to become familiar with the process.

Depending on the nature of your data, you may be able to roll-your-own. Some of our systems have large tables of data that, once collected, remain static. If you have that type of situation you may be able to pre-migrate historical data and then have a reduced window to migrate recent/live data.

Cheers,
Steve