Thanks Even,
Attribute filter fid = <fid> seems fast but ID = <ID> is not fast. Hm,
the whole idea is to use files in S3 instead of data in AWS RDS as the
data is static and RDS costs are high (i.e., it's not a technical
reason). Our use case is mostly about bbox searches and then extracting
single feature or doing a simple mixed spatial and attribute search.
Ari
Even Rouault kirjoitti 22.1.2026 klo 22.09:
Hi Ari,
Looking at the code, I see the driver does read all row groups whereas
it could potentially be improved to use row group level statistics to
skip all of them but the one matching. That said you can probably
workaround the issue by using instead SetAttributeFilter("fid =
<the-fid>") , or querying directly the ID column if that's your
ultimate objective.
More generally Parquet shines more at requesting a significant amount
of data / bulk loading scenarios than just extracting a single feature
where you'll get better performance with regular databases with proper
indices built.
Even
Le 22/01/2026 à 12:49, Ari Jolma a écrit :
Thanks for the replies. I'm progressing but now I hit something I
don't understand.
I have a large GPKG file which I converted into a Parquet file. If I
now do a simple layer.GetFeature(fid) on a random fid on the layer,
the feature is retrieved from GPKG really fast (also if the file is
in S3) but from Parquet it is slow (~ 20 secs) even on local filesystem.
On both files layer.GetFIDColumn() reports "fid". There is a native
"ID" column on the GPKG but fid <> ID.
I used ogr2ogr to create the Parquet file. I had -lco COMPRESSION=None
Ari
Michael Smith kirjoitti 18.1.2026 klo 18.09:
I combine attribute and spatial filters a lot on large parquet files
using a combination of SetSpatialFilter() and SetAttributeFilter()
before querying. I've only had some issues with partition
elimination which have now been fixed. Sometimes the ADBC connection
can be faster to query but opening the file with gdal.OpenEx() is
slower. And ADBC takes more memory. I find the gdal query method
generally better.
Having access to the sql functions of duckdb is the only reason I
ever use ADBC.
Mike
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