Re: Optimize pg_dump schema-only

On 4/28/19 1:21 PM, senor wrote:
> Hi All,
>
> I'm looking for advice for optimizing the pg_dump portion of "pg_upgrade
> --link". Since this schema only dump can't take advantage of parallel

The above is going to need more explanation or a command line example.

> processing with jobs I'm looking for any preparation or configuration
> settings that can improve speed.
>
> 9.2 to 9.6
> CentOS 6/64bit
> 512GB
>
> I see only one CPU of 32 doing anything and it's often at 100%. Disk IO
> is minimal. Memory use varies but always plenty to spare.
>
> During upgrade I'm running:
> Only the upgrade - no other services
> work_mem = 50MB
> maintenance_work_mem = 2048MB
> shared_buffers = 30GB
> max_locks_per_transaction = 4096
> autovacuum = off
> autovacuum_freeze_max_age = 1500000000 #Had previous issues with
> vacuum (to prevent wrap)
>
> Truthfully, I thought I had increased work_mem until starting this
> email. But increasing it is just a guess unless I get advice to do so
> here. I'm at a knowledge level where I can only guess at the relevance
> of vacuum, analyze or any other preparatory actions I can complete
> before taking postgres offline for upgrade. My feeling is that the
> bottleneck is the backend and not pg_dump. School me on that if needed
> please.
>
> Any advice and explanation is appreciated.
>
> - Senor
>

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