Wed Nov 14 13:37:45 EST 2007
slow, but I do not have much experience with sqlite. As Maciek mentioned,
this would have to be improved.
> About flexibility, the SQL subset handled by SQLite is very large, and the
> limitiations (field name length, number of fields,...) inherent to DBF are
> gone. You don't have the geometric/GIS features of PostgreSQL+PostGIS, but
> as far as RDB handling, you might find yourself willing to delve into SQL
> As for the best way to interface with GRASS, I don't have a strong opinion.
> For sure we have to extend v.in.db and db.copy. I mostly use db.execute,
> which becomes somewhat superfluous for SQLite since we might bundle the
> sqlite CLI front-end if we bundle the library. v.db.* is a nice way of
> GRASSifying (and foremost integrating) the DB back-ends, but I can't come
> up with a more GRASSy interface, lest we begin experimenting with d.m from
> where Michael gave us the field list.
> Anyway, I think that if we have consensus about a DBF->SQLite transition we
> should set up a roadmap.
I agree that it wouldn't be a good idea to drop the DBF driver. It is really
used everywhere and is support by many editors, but it is good to have sqlite
as a better alternative already now.
> ---------- Original Message -----------
> From: Maciek Sieczka <werchowyna at epf.pl>
> To: daniel.calvelo at minag.gob.pe
> Cc: Radim Blazek <radim.blazek at gmail.com>, GRASS dev list
> <grass5 at grass.itc.it> Sent: Wed, 19 Oct 2005 21:38:46 +0200
> Subject: Re: [GRASS5] Re: question about sqlite
> > Daniel,
> > Thanks for your message. You have answered questions I have tried to
> > ask on the grasslist recently but didn't know how to, being a woose
> > in DB stuff.
> > My 0,01 PLN: if sqlite improves the v.* and db.* modules speed, as weel
> > as provides functionality to drop/rename/change type of columns without
> > all the complexity of Postgresql I, a simple user, am all my hands
> > and legs for making it a default DB backend in Grass 6.1.
> > Thanks Radim for your effort on implementing sqlite in Grass, and
> > BTW for all the recent wonders you have contributed to Qgis-Grass
> > Maciek
> [UTF-8?]> Daniel Calvelo Aros napisaÅ(a):
> > > From: Radim Blazek <radim.blazek at gmail.com>
> > > Sent: Wed, 19 Oct 2005 10:22:09 +0200
> > >
> > >>On 10/18/05, Michael Barton <michael.barton at asu.edu> wrote:
> > >>>Radim,
> > >>>
> > >>>Could you give me a quick overview of what it means to compile GRASS
> > >>> with sqlite? Here are a couple questions I have.
> > >>>
> > >>>1) Is it simply a driver that lets GRASS recognize a database/table
> > >>> created by sqlite in an active sqlite session started in another
> > >>> process, like a Postgresql table in an active Postgresql session?
> > >
> > > Not quite. A SQLite "database" is a file, just like with DBF. There is
> > > no client-server infrastructure for SQLite. SQLite is transactional, so
> > > you can open the same file in two sessions, and there will be
> > > concurrent access, mostly problem-free.
> > >
> > >>>2) Does it/can it active an sqlite session from within GRASS?
> > >
> > > What it does is access the indicated sqlite file using the SQLite
> > > language and tranaction infrastructure, through the libsqlite library.
> > >
> > >>>3) Are there other features that I'm not asking about that I should
> > >>> know?
> > >>
> > >>The sqlite driver works like any other db driver (dbf, pg, mysql,
> > >> odbc). You can use an existing database or create a new one from
> > >> GRASS. Just set the driver and database file with db.connect and all
> > >> new attribute tables will be created in that database.
> > >>
> > >>Radim
> > >
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> > --------------------
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