On Sun, Feb 26, 2012 at 12:37 PM, Stefan Keller <sfkeller(at)gmail(dot)com> wrote:
> 2012/2/26 Andy Colson <andy(at)squeakycode(dot)net> wrote:
>>>> How about after you load the data, vacuum freeze it, then do something
>>>> SELECT count(*) FROM osm_point WHERE tags @> 'tourism=>junk'
>>> That good idea is what I proposed elsewhere on one of the PG lists and
>>> got told that this does'nt help.
>> I don't buy that. Did you test it? Who/where did you hear this? And...
>> how long does it take after you replace the entire table until things are
>> good and cached? One or two queries?
>> After a complete reload of the data, do you vacuum freeze it?
>> After a complete reload of the data, how long until its fast?
> Just after the second query. You can try it yourself online here:
The second instance of the exact same query is fast. How long until
all similar but not identical queries are fast?
In response to
pgsql-performance by date
|Next:||From: Tomas Vondra||Date: 2012-02-28 16:05:08|
|Subject: Re: [PERFORM] Re: [PERFORM] Re: [PERFORM] Re: [PERFORM] Re: 回复： [PERFORM] PG as in-memory db? How to warm up and re-populate buffers? How to read in all tuples into memory?|
|Previous:||From: Jeff Janes||Date: 2012-02-28 15:14:46|
|Subject: Re: 回复： [PERFORM] PG as in-memory db? How to w?==?UTF-8?Q?arm up and re-populate buffers? How to read in all tuples in?==?UTF-8?Q?to memory?|