Marc Cousin wrote:
Your effective_cache_size is really small for the system you seem to have -
its the size of IO caching your os is doing and uses no resources itself.
And 800MB of that on a system with that amount of data seems a bit unlikely
;-)
Using `free` you can see the amount of io caching your OS is doing atm. in
the 'cached' column.
That possibly might tip some plans in a direction you prefer.
What kind of machine are you running this on?
I played with this parameter too, and it didn't influence the plan. Anyway, the
doc says it's the OS cache available for one query,
No they don't. I'm guessing you're getting mixed up with work_mem.
> and there may be a lot of
insert queries at the same time, so I chose to be conservative with this
value. I tried it with 8GB too, the plans were the same.
The OS cache is around 8-10GB by the way.
That's what you need to set effective_cache_size to then.
--
Richard Huxton
Archonet Ltd
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