[postgis-devel] AddRasterConstraints failing to create extents in raster_column view

[Bborie Park]

No, you can't specify the criteria of a raster constraint.  What
you're forgetting is that even if you could set the criteria of the
constraint, the table still needs to inspect the data in the table to
ensure that the constraint isn't violated.  This inspection is where
most of the time is spent.

Based upon the output message, your PostGIS install is either 2.0.0 or
2.0.1.  Upgrade to 2.0.3 as some changes were made to attempt
alternate routes...

-bborie

On Wed, Apr 17, 2013 at 7:04 AM, ryagz <raghavendra at vizexperts.com> wrote:
>>All constraints generated through AddRasterConstraints() is done on
>>the data in the table.  You can always load one raster file and apply
>>those constraints that can are common for all raster files, usually
>>SRID, scale, skew, blocksize, same alignment, number of bands, pixel
>>types, nodata_values and out-db.
>
>
> If i get values like SRID, Scale etc from a raster file can i directly set
> those as rasterConstraints? if so, can u please refer me to how it can be
> done.
>
>>What output is there when you try to apply the extent constraint?  Are
>>you getting the message "Unable to get the extent of the raster
>>column. Attempting memory efficient (slower) approach"?
>
> _add_raster_constraint_extent is also taking quite some time, i would have
> to apply this on base table and all the overview tables. so cumulatively its
> large. Please let me know if this can also be reduced some way.
>
>>See what happens when you call the underlying extent constraint
>>addition function:
>>SELECT _add_raster_constraint_extent(SCHEMA_NAME, TABLE_NAME, COLUMN_NAME);
>
> I tried the query SELECT _add_raster_constraint_extent('tkp_testing',
> 'test_wb32_64', 'rast');
>
> and the return result was 'f'.
>
> Output message was :
>
> NOTICE:  Unable to get the extent of a sample raster
>
> Total query runtime: 355277 ms.
> 1 row retrieved.
>
>
>
>
> --
> View this message in context: http://postgis.17.x6.nabble.com/AddRasterConstraints-failing-to-create-extents-in-raster-column-view-tp5003029p5003038.html
> Sent from the PostGIS - Dev mailing list archive at Nabble.com.
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