Re: 15 pg_upgrade with -j

On 5/22/23 16:29, Jeff Ross wrote:
> On 5/22/23 5:24 PM, Adrian Klaver wrote:
>> On 5/22/23 16:20, Jeff Ross wrote:
>>> Hello!
>>>

>>
>> From docs:
>>
>> https://www.postgresql.org/docs/current/pgupgrade.html
>>
>> The --jobs option allows multiple CPU cores to be used for
>> copying/linking of files and to dump and restore database schemas in
>> parallel; a good place to start is the maximum of the number of CPU
>> cores and tablespaces. This option can dramatically reduce the time to
>> upgrade a multi-database server running on a multiprocessor machine.
>>
>> So is the 1400G mostly in one database in the cluster?
>>
>>>
>>> The full commands we are using for pg_upgrade are pretty stock:

> Yes, one big database with about 80 schemas and several other smaller
> databases so -j should help, right?

As I understand it no. That the parallelism is between databases not
within a database. Further that 'database schemas' refers to schema as
the overall database object definitions not the namespaces known as
schemas in the database.

> '
> Jeff

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com