Re: upgrade and migrate

On 12/3/19 10:48 PM, Michael Paquier wrote:
> On Tue, Dec 03, 2019 at 10:32:22PM +0000, Julie Nishimura wrote:
>> Hello, what is the best way to migrate from PostgreSQL 8.3.11 on
>> x86_64-redhat-linux-gnu to PostgreSQL 9.6.16 on x86_64-pc-linux-gnu
>> server, with minimal downtime?
>> The caveat is the source has about 80 databases overall almost 30
>> TB. I could migrate the smallest ones (up to 1 tb) using pg_dump and
>> pg_restore, but the largest hot database is almost 17 tb, and I am
>> not sure how to approach this effort in a better and efficient way?
> pg_upgrade could be one way to go here.  That's not the scale pg_dump
> would be very good at.  I would have personally avoided using pg_dump
> above 10~20GB.

I've successfully migrated three 1-2 TB databases across data centers in 
about 12 hours each, from 8.4 to 9.6.  Used eight threads, and the 9.6 
pg_dump against the 8.4 database.  17TB is a "bridge too far", though...

> Depending on the downtime you are ready to accept,
> a migration based on Slony could be something to investigate.
> --
> Michael

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