>
> Would you care to repeat those two SELECTs, but after making indices on the
> X and Y columns ?
>
Simon, Tim, forgot to mention, there were also two indexes in the test db,
on X and on Y. Without them 1,8 seconds and 1/10 data flow would not be
possible ))
On Mon, Mar 22, 2010 at 2:52 PM, Tim
Another addendum: apologies -- I hope my
discussion was clear enough despite the disconnect between my head and
my fingers; I just noticed that I had typed "INNER JOIN" (yikes) rather
than "INNER LOOP", by which I mean fetching the rowids using an index
(on LATITUDE say) and then having to l
On 3/22/2010 7:32 AM, Tim Romano wrote:
> On 3/22/2010 2:15 AM, Max Vlasov wrote:
>
>>> Assuming a table where Latitude column and Longitude column each have
>>> their own index:
>>>
>>> perform select #1 which returns the rowids of rows whose latitude meets
>>> criteria
>>> INTERSECT
>>> perfo
On 3/22/2010 2:15 AM, Max Vlasov wrote:
>> Assuming a table where Latitude column and Longitude column each have
>> their own index:
>>
>> perform select #1 which returns the rowids of rows whose latitude meets
>> criteria
>> INTERSECT
>> perform select #2 which returns the rowids of rows whose lon
On 22 Mar 2010, at 6:15am, Max Vlasov wrote:
> Ok, just test.
>
> Created a base with a table
>
> CREATE TABLE [TestTable] ([Id] INTEGER PRIMARY KEY AUTOINCREMENT,
> [X] INTEGER,[Y] INTEGER)
>
> Filled with 1,000,000 records:
>
> INSERT INTO TestTable
> (X, Y)
> VALUES
> ((random() % 5) +
>
> Assuming a table where Latitude column and Longitude column each have
> their own index:
>
> perform select #1 which returns the rowids of rows whose latitude meets
> criteria
> INTERSECT
> perform select #2 which returns the rowids of rows whose longitude meets
> criteria
>
>
Ok, just test.
On 3/21/2010 5:22 PM, Max Vlasov wrote:
> On Sun, Mar 21, 2010 at 3:50 PM, Tim Romano wrote:
>
>
>> For someone who doesn't read C, could someone who knows please describe
>> the SQLite INTERSECT algorithm? What optimizations are available to it?
>> Does INTERSECT have to assume that neither
On Sun, Mar 21, 2010 at 3:50 PM, Tim Romano wrote:
> For someone who doesn't read C, could someone who knows please describe
> the SQLite INTERSECT algorithm? What optimizations are available to it?
> Does INTERSECT have to assume that neither vector is pre-sorted? Here's
> the background of my
On 3/21/2010 10:26 AM, Igor Tandetnik wrote:
> Tim Romano wrote:
>
>> For latitude/longitude queries
>>
> Without diving into the details of your situation, I wonder if you are aware
> of R-Tree extension:
>
> http://www.sqlite.org/rtree.html
>
Thank you Igor. I had read about R-TRE
Tim Romano wrote:
> For latitude/longitude queries
Without diving into the details of your situation, I wonder if you are aware of
R-Tree extension:
http://www.sqlite.org/rtree.html
--
Igor Tandetnik
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