On Sat, Jun 25, 2011 at 7:25 AM, Luuk wrote:
> I create a test database with almost 10 milion rows.
> I'm surprised to see that the first SELECT below is much slower than the
> sum of the next three SELECTs.
>
> Can anyone give a hint why this is the case?
>
> SQLite version 3.7.2
> Enter ".help"
On 25 Jun 2011, at 4:12pm, Black, Michael (IS) wrote:
> Can the optimizer recognize these "instant" functions and perhaps lean
> towards using them?
It already does. That's why max(x) takes no time when you have an index on (x).
> Are there cases where this would NOT be good?
Theoretically,
cussion of SQLite Database
Subject: EXT :Re: [sqlite] question about sqlite aggregate funcitons
On 25 Jun 2011, at 1:37pm, Luuk wrote:
> Giving the SELECTs i a different order does not improve thing (much).
> BTW, i'm doing this on a Windows 7 machine, and will test what happens
> o
On 25 Jun 2011, at 1:37pm, Luuk wrote:
> Giving the SELECTs i a different order does not improve thing (much).
> BTW, i'm doing this on a Windows 7 machine, and will test what happens
> on a Linux machine too, to see if there's difference.
>
> SQLite version 3.7.2
> Enter ".help" for instruction
On 25-06-2011 15:15, Black, Michael (IS) wrote:
> OK...I generated 10M ints and imported them. I get times that I would expect.
>
> select with all 3 is slightly less then the sum of the other 3 individually.
>
>
>
> main()
> {
> int i;
> for(i=0;i<1000;i++) {
>
On 25-06-2011 15:37, Black, Michael (IS) wrote:
> And...this select does it at the speed you expect since it uses the indexes
> for min/max.\
>
>
>
> This one I ran with 3.7.7
>
>
>
> sqlite> select * from (select min(i) from test) as a,(select max(i) from
> test) as b, (select count(i) fro
s-boun...@sqlite.org] on
behalf of Black, Michael (IS) [michael.bla...@ngc.com]
Sent: Saturday, June 25, 2011 8:15 AM
To: General Discussion of SQLite Database
Subject: EXT :Re: [sqlite] question about sqlite aggregate funcitons
OK...I generated 10M ints and imported them. I get times that I would
ior Scientist
NG Information Systems
Advanced Analytics Directorate
From: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] on
behalf of Luuk [luu...@gmail.com]
Sent: Saturday, June 25, 2011 7:37 AM
To: sqlite-users@sqlite.org
Subject: EXT :Re
l.com]
> Sent: Saturday, June 25, 2011 6:25 AM
> To: General Discussion of SQLite Database
> Subject: EXT :[sqlite] question about sqlite aggregate funcitons
>
> I create a test database with almost 10 milion rows.
> I'm surprised to see that the first SELECT below i
m: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] on
behalf of Luuk [luu...@gmail.com]
Sent: Saturday, June 25, 2011 6:25 AM
To: General Discussion of SQLite Database
Subject: EXT :[sqlite] question about sqlite aggregate funcitons
I create a test database with almost 10 m
I create a test database with almost 10 milion rows.
I'm surprised to see that the first SELECT below is much slower than the
sum of the next three SELECTs.
Can anyone give a hint why this is the case?
SQLite version 3.7.2
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
11 matches
Mail list logo
