[postgis-users] Fwd: PostGIS Out-DB Raster Not Behaving As Expected

[Tumasgiu Rossini]

Maybe a warning showing up when using -s and -R options together could be a
nice thing to do ?
Or maybe implementing another option which would use st_setsrid instead of
st_transform.


2017-04-11 14:25 GMT+02:00 Tumasgiu Rossini <rossini.t at gmail.com>:

> Hi,
>
> I think I found the probelm, it is the -s option which make the sql
> applying a st_transfrom on the raster to reproject it into the desired CRS
> before inserting it in the table, thus creating an in-db raster.
>
> 2017-04-11 12:14 GMT+02:00 Osahon Oduware <osahon.gis at gmail.com>:
>
>> Hi Regina,
>>
>> I would like to add that the SHOW command below returns "on":
>>
>> SHOW postgis.enable_outdb_rasters;
>>
>> which I believe indicates that the environment variable is SET to enable
>> out-db raster. However, the result from your 1st query shows that the
>> raster table isn't created with out-db. Any reason for this behaviour?
>>
>>
>> ---------- Forwarded message ----------
>> From: Osahon Oduware <osahon.gis at gmail.com>
>> Date: Tue, Apr 11, 2017 at 10:07 AM
>> Subject: Re: [postgis-users] PostGIS Out-DB Raster Not Behaving As
>> Expected
>> To: PostGIS Users Discussion <postgis-users at lists.osgeo.org>
>> Cc: Regina Obe <lr at pcorp.us>, Jorge Gustavo Rocha <jgr at di.uminho.pt>
>>
>>
>> Hi Regina,
>>
>> I have tried the queries above. For the related raster table,
>>
>> SELECT r_table_name, r_raster_column, out_db FROM raster_columns; RETURNS
>> "raster_table","rast","[False, False, False]"
>>
>> SELECT t.rid, (md).isoutdb, (md).path
>> FROM nj_ned AS t, ST_BandMetaData(t.rast) AS md
>> limit 1; RETURNS
>> 1,False,""
>>
>> I believe from the result of the 1st query that out-db is not enabled.
>> However, the environment variable POSTGIS_ENABLE_OUTDB_RASTERS is SET to
>> 1.* I have tried to also enable it with the following, restarted the
>> postgres Service, and re-loaded the raster, but the 1st query gives the
>> same result:*
>>
>> ALTER DATABASE <database_name> SET postgis.enable_outdb_rasters TO True;
>>
>>
>> Please, could you help me further on what I am not doing right to enable
>> the out-db rasters.
>>
>>
>>
>>
>> On Mon, Apr 10, 2017 at 8:31 PM, Regina Obe <lr at pcorp.us> wrote:
>>
>>> You should also check the following queries
>>>
>>> SELECT r_table_name, r_raster_column, out_db FROM raster_columns;
>>>
>>> Out_db should be true for all your bands for the specific table and as
>>> Jorge mentioned, you shouldn't see any over view tables (which start with
>>> o_..{table}.
>>> I believe QGIS internally tries to use over view tables to speed things
>>> up, so it's possible it's using an overview table instead of the main outdb
>>> table if you are zoomed out enough.
>>>
>>> For outdb, querying the meta data of the raster will tell you the path
>>> if it's an outdb.  Replace nj_ned with your table name.
>>>
>>> SELECT t.rid, (md).isoutdb, (md).path
>>> FROM nj_ned AS t, ST_BandMetaData(t.rast) AS md
>>> limit 1;
>>>
>>> Hope that helps,
>>> Regina
>>> http://postgis.us
>>> http://postgis.net
>>>
>>>
>>> -----Original Message-----
>>> From: postgis-users [mailto:postgis-users-bounces at lists.osgeo.org] On
>>> Behalf Of Jorge Gustavo Rocha
>>> Sent: Monday, April 10, 2017 2:14 PM
>>> To: postgis-users at lists.osgeo.org
>>> Subject: Re: [postgis-users] PostGIS Out-DB Raster Not Behaving As
>>> Expected
>>>
>>> Hi,
>>>
>>> According to the documentation [1], if you add the option -l (like -l
>>> 2,4,8,16 ), the overviews are created in the database, even if you use
>>> the -R option.
>>>
>>> But since you did not use the -l option, I don't know how you can see
>>> the images.
>>>
>>> Can you check the layer properties in QGIS? Are any pyramids available
>>> or not?
>>>
>>> Regards,
>>>
>>> Jorge
>>>
>>>
>>>  s 16:52 de 10-04-2017, Osahon Oduware escreveu:
>>> > Hi All,
>>> >
>>> > I created an out-db raster using the following syntax:
>>> >
>>> > raster2pgsql -s {srid} -c -R -I -C -F -t auto {absolute_file_path}
>>> > public.{table} | psql -h {host} -p {port} -d {database} -U {user}
>>> >
>>> > The table was created successfully. I wanted to confirm that the
>>> > actual file is being read from the location in the filesystem by
>>> > performing the following steps:
>>> > 1) I moved the raster file to a different location.
>>> > 2) I opened QGIS and attempted to load the raster from PostGIS table.
>>> >
>>> > I was surprised that QGIS could load the file. *How is this possible
>>> > when the actual raster data is not stored in the database table?*
>>> >
>>> >
>>> > _______________________________________________
>>> > postgis-users mailing list
>>> > postgis-users at lists.osgeo.org
>>> > https://lists.osgeo.org/mailman/listinfo/postgis-users
>>> >
>>>
>>> J. Gustavo
>>> --
>>> Jorge Gustavo Rocha
>>> Departamento de Inform tica
>>> Universidade do Minho
>>> 4710-057 Braga
>>> Tel: +351 253604480 <+351%20253%20604%20480>
>>> Fax: +351 253604471 <+351%20253%20604%20471>
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>>
>>
>>
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