[sqlite] How to use aux_data effectively?

2013-09-06 Thread Pepijn Van Eeckhoudt
Hi, In the extension I'm developing (https://bitbucket.org/luciad/libgpkg) I'm currently adding support for queries like: select Distance( GeomFromText('Point(13.457 3)'), geometry ) from table; GeomFromText takes a string and outputs a geometry blob Distance takes two geometry blobs and retu

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Richard Hipp
On Fri, Sep 6, 2013 at 11:38 AM, Pepijn Van Eeckhoudt < pep...@vaneeckhoudt.net> wrote: > Hi, > > In the extension I'm developing (https://bitbucket.org/luciad/libgpkg) > I'm currently adding support for queries like: > select Distance( > GeomFromText('Point(13.457 3)'), > geometry > ) from ta

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Dominique Devienne
On Fri, Sep 6, 2013 at 5:40 PM, Richard Hipp wrote: > On Fri, Sep 6, 2013 at 11:38 AM, Pepijn Van Eeckhoudt < > pep...@vaneeckhoudt.net> wrote: > > > In order to speed up the distance function I was wondering if I could > > use aux_data to cache the parsed version of the first parameter since > >

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Dominique Devienne
On Fri, Sep 6, 2013 at 6:14 PM, Pepijn Van Eeckhoudt < pep...@vaneeckhoudt.net> wrote: > On 06 Sep 2013, at 17:58, Dominique Devienne wrote: > > >> select Distance( constGeom, geometry ) from table, (select > >> GeomFromText('Point(13.457 3)') as constGeom ); > > > > Clever. Thanks for that. > >

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Pepijn Van Eeckhoudt
On 06 Sep 2013, at 17:58, Dominique Devienne wrote: >> select Distance( constGeom, geometry ) from table, (select >> GeomFromText('Point(13.457 3)') as constGeom ); > > Clever. Thanks for that. Simple and elegant. Thanks for the idea, I'll give it a try. > Or make your Distance function imple

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Dominique Devienne
On Fri, Sep 6, 2013 at 5:51 PM, Simon Davies wrote: > On 6 September 2013 16:38, Pepijn Van Eeckhoudt > wrote: > > Hi, > > > > In the extension I'm developing (https://bitbucket.org/luciad/libgpkg) > > I'm currently adding support for queries like: > > select Distance( > > GeomFromText('Point(1

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Simon Davies
On 6 September 2013 16:38, Pepijn Van Eeckhoudt wrote: > Hi, > > In the extension I'm developing (https://bitbucket.org/luciad/libgpkg) > I'm currently adding support for queries like: > select Distance( > GeomFromText('Point(13.457 3)'), > geometry > ) from table; > > GeomFromText takes a str

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Peter Aronson
s non-NULL. Peter - Original Message - > From: Pepijn Van Eeckhoudt > To: sqlite-users@sqlite.org > Cc: > Sent: Friday, September 6, 2013 8:38 AM > Subject: [sqlite] How to use aux_data effectively? > > Hi, > > In the extension I'm developing (https:

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Pepijn Van Eeckhoudt
On 06 Sep 2013, at 17:51, Simon Davies wrote: >> Are there any other ways to kind of memoize the GeomFromText function >> (or the parameters to distance) besides aux_data? > > select Distance( constGeom, geometry ) from table, (select > GeomFromText('Point(13.457 3)') as constGeom ); I just tri

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Pepijn Van Eeckhoudt
e GeomFromText has to do > is to return the Geometry blob when sqlite3_get_auxdata returns non-NULL. > > Peter > > - Original Message - >> From: Pepijn Van Eeckhoudt >> To: sqlite-users@sqlite.org >> Cc: >> Sent: Friday, September 6, 2013 8:38 AM

Re: [sqlite] How to use aux_data effectively?

2013-09-06 Thread Peter Aronson
13 4:47 PM > Subject: Re: [sqlite] How to use aux_data effectively? > > Peter, > > Thanks for the suggestion but that's not the part I'm trying to optimise > at the moment. It could be useful to use auxdata there as well to avoid > reparsing the text of cour

Re: [sqlite] How to use aux_data effectively?

2013-09-07 Thread Pepijn Van Eeckhoudt
On 07 Sep 2013, at 02:03, Peter Aronson wrote: > Ah, I see. Yeah, that would be trickier. You could save off the geometry > blob and the GEOSPreparedGeometry object in a structure passed in to > sqlite3_create_function and accessed via sqlite3_user_data and memcmp each > geometry blob with t