[GRASS-dev] [GRASS-SVN] r73995 - grass/trunk/scripts/v.db.addtable
Huidae Cho
grass4u at gmail.com
Tue Jan 29 14:16:56 PST 2019
I just did a quick search and found that these modules (i.segment.stats,
r.mwprecip, v.in.geopaparazzi, v.link.precip, v.out.gps, v.ply.rectify,
v.unpack) create/copy new tables themselves without the index and invoke
v.db.connect. For now, we cannot move index creation to v.db.addtable.
Huidae
On Tue, Jan 29, 2019 at 4:12 PM Huidae Cho <grass4u at gmail.com> wrote:
> Yes. Like you said, v.db.connect followed by v.db.connect -d gives me the
> same pg errors and grass warning. I agree with you that the preferred
> solution would be to create the index in v.db.addtable, not in v.db.connect
> "if" no modules rely on v.db.connect for creating the unique index.
>
> Huidae
>
>
>
>
> On Tue, Jan 29, 2019 at 3:51 PM Markus Metz <markus.metz.giswork at gmail.com>
> wrote:
>
>>
>>
>> On Tue, Jan 29, 2019 at 4:12 PM Huidae Cho <grass4u at gmail.com> wrote:
>> >
>> > You're right. It was a warning with PostgresSQL error messages
>> (attached below), not a fatal error. But I don't think there should be any
>> warning (or PostgreSQL errors) because the user didn't do anything wrong
>> here (v.edit map tool=create; v.db.addtable).
>>
>> Hmm yes I agree. At least for v.db.addtable the index can be created by
>> v.db.connect when the new table is actually linked to the vector map.
>>
>> You might still get these PG errors when you try to connect an already
>> existing table, but this is probably not happening very often, and
>> v.db.connect finishes anyway.
>>
>> Markus M
>>
>> >
>> > DBMI-PostgreSQL driver error:
>> > Unable to create index: create unique index tmp2_cat on tmp2 ( cat )
>> > ERROR: relation "tmp2_cat" already exists
>> >
>> >
>> > DBMI-PostgreSQL driver error:
>> > Unable to create index: create unique index tmp2_cat on tmp2 ( cat )
>> > ERROR: relation "tmp2_cat" already exists
>> >
>> >
>> > WARNING: Cannot create index
>> > here
>> > WARNING: Values in column <cat> will be overwritten
>> > Reading features...
>> > 100%
>> > Updating database...
>> > 100%
>> >
>> > Huidae
>> >
>> > On Tue, Jan 29, 2019 at 9:37 AM Markus Metz <
>> markus.metz.giswork at gmail.com> wrote:
>> >>
>> >>
>> >>
>> >> On Sun, Jan 27, 2019 at 11:21 AM Markus Metz <
>> markus.metz.giswork at gmail.com> wrote:
>> >> >
>> >> >
>> >> >
>> >> > On Sat, Jan 26, 2019 at 2:50 PM Huidae Cho <grass4u at gmail.com>
>> wrote:
>> >> > >
>> >> > > Markus,
>> >> > >
>> >> > > If there is a linked table, v.db.addtable stops in line 106. If
>> not, this script doesn't create a unique index and calls v.db.connect.
>> v.db.connect adds a db link in line 317 and creates a unique index
>> (db_create_index2) in line 334 if linking was successful. SQLite didn't
>> complain when both modules created the same unique index, but PostgreSQL
>> failed in v.db.connect (2nd time creating the same unique index).
>> >>
>> >> What do you mean with "failed"? v.db.connect will issue a warning if
>> it can not create an index but finish successfully.
>> >>
>> >> Markus M
>> >>
>> >> >> Not sure which code was added first/later. I think it's more of how
>> we design both modules. v.db.connect will fail if we try to link a table
>> with a unique index. Isn't v.db.connect supposed to "just" connect a table
>> to a layer (without creating any database objects like index)? Which module
>> should be responsible for creating unique indices?
>> >> > >
>> >> > > Before this commit:
>> >> > > 1. v.db.addtable creates unique index
>> >> > > 2. v.db.connect tries to create unique index again ==> fatal error
>> >> > >
>> >> > > After this commit:
>> >> > > 1. v.db.addtable doesn't create unique index
>> >> > > 2. v.db.connect creates unique index
>> >> > >
>> >> > > Probably, it should be:
>> >> > > 1. v.db.addtable should create unique index
>> >> > > 2. v.db.connect shouldn't try to create unique index? Just
>> "connect"...
>> >> >
>> >> > Yes, this is the preferred solution. Consider v.db.connect -d
>> followed by v.db.connect, i.e. disconnecting a table and then reconnecting
>> the same table: in this case v.db.connect should also fail with PostgreSQL.
>> IMHO, a unique index should only be created when the table is created.
>> >> >
>> >> > Markus M
>> >> >
>> >> > >
>> >> > > Regards,
>> >> > > Huidae
>> >> > >
>> >> > > On Sat, Jan 26, 2019 at 7:39 AM Markus Neteler <neteler at osgeo.org>
>> wrote:
>> >> > >>
>> >> > >> Hi,
>> >> > >>
>> >> > >> On Tue, Jan 22, 2019 at 3:51 AM <svn_grass at osgeo.org> wrote:
>> >> > >> >
>> >> > >> > Author: hcho
>> >> > >> > Date: 2019-01-21 18:51:33 -0800 (Mon, 21 Jan 2019)
>> >> > >> > New Revision: 73995
>> >> > >> >
>> >> > >> > Modified:
>> >> > >> > grass/trunk/scripts/v.db.addtable/v.db.addtable.py
>> >> > >> > Log:
>> >> > >> > v.db.addtable: Do not create unique index from this script;
>> v.db.connect will try to create it again causing some drivers to fail
>> (PostgreSQL)
>> >> > >> >
>> >> > >> > Modified: grass/trunk/scripts/v.db.addtable/v.db.addtable.py
>> >> > >> >
>> ===================================================================
>> >> > >> > --- grass/trunk/scripts/v.db.addtable/v.db.addtable.py
>> 2019-01-21 22:37:59 UTC (rev 73994)
>> >> > >> > +++ grass/trunk/scripts/v.db.addtable/v.db.addtable.py
>> 2019-01-22 02:51:33 UTC (rev 73995)
>> >> > >> > @@ -139,16 +139,6 @@
>> >> > >> > except CalledModuleError:
>> >> > >> > grass.fatal(_("Unable to create table <%s>") %
>> table)
>> >> > >> >
>> >> > >> > - # create index, see db/driver/*/index.c
>> >> > >> > - if driver != "dbf":
>> >> > >> > - sql = "CREATE UNIQUE INDEX %s_%s ON %s (%s)" %
>> (table, key, table, key)
>> >> > >> > - try:
>> >> > >> > - grass.run_command('db.execute',
>> >> > >> > - database=database,
>> driver=driver, sql=sql)
>> >> > >> > - except:
>> >> > >> > - grass.warning(_("Unable to create index on
>> table <%s>") % table)
>> >> > >> > - pass
>> >> > >> > -
>> >> > >> > # connect the map to the DB:
>> >> > >> > if schema:
>> >> > >> > table = '{schema}.{table}'.format(schema=schema,
>> table=table)
>> >> > >>
>> >> > >> just a conceptual question:
>> >> > >> ... are we sure that this index creation removal never leads to a
>> >> > >> table without index?
>> >> > >>
>> >> > >> Markus
>> >> > >
>> >> > >
>> >> > >
>> >> > > --
>> >> > > Huidae Cho, Ph.D., GISP, PE (MD), CFM, M.ASCE
>> >> > > Open Source GIS Developer, GRASS GIS Development Team
>> >> > > _______________________________________________
>> >> > > grass-dev mailing list
>> >> > > grass-dev at lists.osgeo.org
>> >> > > https://lists.osgeo.org/mailman/listinfo/grass-dev
>> >
>> >
>> >
>> > --
>> > Huidae Cho, Ph.D., GISP, PE (MD), CFM, M.ASCE
>> > Open Source GIS Developer, GRASS GIS Development Team
>>
>
>
> --
> Huidae Cho, Ph.D., GISP, PE (MD), CFM, M.ASCE
> Open Source GIS Developer, GRASS GIS Development Team
>
--
Huidae Cho, Ph.D., GISP, PE (MD), CFM, M.ASCE
Open Source GIS Developer, GRASS GIS Development Team
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