Re: Different memory allocation strategy in Postgres 11? - Mailing list pgsql-general

From Jeff Janes
Subject Re: Different memory allocation strategy in Postgres 11?
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Msg-id CAMkU=1xedG=UBiUXtR+XMgeKdtep=9DxyOgWVMjW7QXFP3yP6g@mail.gmail.com
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In response to Different memory allocation strategy in Postgres 11?  (Thomas Kellerer <spam_eater@gmx.net>)
Responses Re: Different memory allocation strategy in Postgres 11?
List pgsql-general
On Fri, Oct 26, 2018 at 9:12 AM Thomas Kellerer <spam_eater@gmx.net> wrote:
I have a Postgres instance running on my Windows laptop for testing purposes.

I typically configure "shared_buffers = 4096MB" on my 16GB system as sometimes when testing, it pays off to have a bigger cache.

With Postgres 10 and earlier, the Postgres process(es) would only allocate that memory from the operating system when needed.
So right after startup, it would only consume several hundred MB, not the entire 4GB

However with Postgres 11 I noticed that it immediately grabs the complete memory configured for shared_buffers during startup.

It's not really a big deal, but I wonder if that is an intentional change or a result from something else?

Do you have pg_prewarm in shared_preload_libraries?

Cheers,

Jeff 

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