Re: Pg_upgrade speed for many tables

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От Magnus Hagander
Тема Re: Pg_upgrade speed for many tables
Дата
Msg-id CABUevEzyaL2iiJqqa4BQHYbiScN3+H7JA_mduQm+mbMSYAXOqA@mail.gmail.com
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Ответ на Re: Pg_upgrade speed for many tables  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: Pg_upgrade speed for many tables  (Tom Lane <tgl@sss.pgh.pa.us>)
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On Mon, Nov 5, 2012 at 9:14 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Bruce Momjian <bruce@momjian.us> writes:
> Magnus reported that a customer with a million tables was finding
> pg_upgrade slow.

You sure there's not an O(N^2) issue in there somewhere? 

> I don't see anything unsafe about having pg_upgrade use
> synchronous_commit=off.

No objection, but this seems unlikely to be better than linear speedup,
with a not-terribly-large constant factor.

BTW, does pg_upgrade run pg_restore in --single-transaction mode?
That would probably make synchronous_commit moot, at least for that
step.

 
It doesn't use pg_restore at all - it uses the dump from pg_dumpall, which you can't reload with pg_restore. 


--
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/

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