2016-12-21 0:01 GMT+01:00 Tom Lane :
> Pavel Stehule writes:
> > I am trying to fix slow query on PostgreSQL 9.5.4.
> > The data are almost in RAM
>
> If it's all in RAM, you'd likely be well-served to lower random_page_cost.
> It looks to me like the planner is estimating pretty accurately how m
Pavel Stehule writes:
> I am trying to fix slow query on PostgreSQL 9.5.4.
> The data are almost in RAM
If it's all in RAM, you'd likely be well-served to lower random_page_cost.
It looks to me like the planner is estimating pretty accurately how many
heap fetches will be eliminated by using the
2016-12-20 13:55 GMT+01:00 Robert Haas :
> On Tue, Dec 20, 2016 at 2:13 AM, Pavel Stehule
> wrote:
> > 2016-12-19 23:28 GMT+01:00 Robert Haas :
> >> On Sat, Dec 17, 2016 at 3:30 AM, Pavel Stehule >
> >> wrote:
> >> > -> Bitmap Heap Scan on "Zasilka" (cost=5097.39..5670.64 rows=1
> >> > width=1
On Tue, Dec 20, 2016 at 2:13 AM, Pavel Stehule wrote:
> 2016-12-19 23:28 GMT+01:00 Robert Haas :
>> On Sat, Dec 17, 2016 at 3:30 AM, Pavel Stehule
>> wrote:
>> > -> Bitmap Heap Scan on "Zasilka" (cost=5097.39..5670.64 rows=1
>> > width=12)
>> > (actual time=62.253..62.400 rows=3 loops=231)
>> .
2016-12-19 23:28 GMT+01:00 Robert Haas :
> On Sat, Dec 17, 2016 at 3:30 AM, Pavel Stehule
> wrote:
> > -> Bitmap Heap Scan on "Zasilka" (cost=5097.39..5670.64 rows=1
> width=12)
> > (actual time=62.253..62.400 rows=3 loops=231)
> ...
> > When I disable bitmap scan, then the query is 6x time fas
On Sat, Dec 17, 2016 at 3:30 AM, Pavel Stehule wrote:
> -> Bitmap Heap Scan on "Zasilka" (cost=5097.39..5670.64 rows=1 width=12)
> (actual time=62.253..62.400 rows=3 loops=231)
...
> When I disable bitmap scan, then the query is 6x time faster
>-> Index Scan using "Zasilka_idx_Dopravce
