Re: surprising query optimisation - Mailing list pgsql-general

From Chris Withers
Subject Re: surprising query optimisation
Date
Msg-id 6ba91527-e19e-d6f1-8273-1561cdaba2ad@withers.org
Whole thread Raw
In response to Re: surprising query optimisation  (Gavin Flower <GavinFlower@archidevsys.co.nz>)
Responses Re: surprising query optimisation
List pgsql-general
On 30/11/2018 22:10, Gavin Flower wrote:
> 
> I once optimised a very complex set queries that made extensive use of 
> indexes.  However, with the knowledge I have today, I would have most 
> likely had fewer and smaller indexes.  As I now realize, that some of my 
> indexes were probably counter productive, especially as I'd given no 
> thought to how much RAM would be required to host the data plus 
> indexes!  Fortunately, while the objective was to run all those queries 
> within 24 hours, they actually only took a couple of hours.

So, interestingly, this box has 250GB memory in it, and even though I've 
set effective_cache_size to 200GB, I only see 9G of memory being used. 
How can I persuade postgres to keep more in memory?

cheers,

Chris


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