Re: [Geoserver-users] Question about GEOS-9757

[Andrea A. <and...@ge...>]

Hi Soren,
yes, that's a good idea in general... I guess you're using a data source
that does not perform any sort of paged access?
E.g., when working against a shapefile, only one record will be actually
read by DataUtilities.first, and when using a database,
a "fetch size" worth of records should be transferred (which is still a lot
more than strictly needed).

While you're at it, I would also add a limit of 1 feature in the Query
object, which depending on your data source and
data structures, might have a more of an effect of limiting the attributes
(doing both is best).

Please make a pull request with the suggested code change.

Regards,

Andrea Aime


==
GeoServer Professional Services from the experts!

Visit http://bit.ly/gs-services-us for more information.
==

Ing. Andrea Aime
@geowolf
Technical Lead

GeoSolutions Group
phone: +39 0584 962313

fax:     +39 0584 1660272

mob:   +39  339 8844549

https://www.geosolutionsgroup.com/

http://twitter.com/geosolutions_it

-------------------------------------------------------

Con riferimento alla normativa sul trattamento dei dati personali (Reg. UE
2016/679 - Regolamento generale sulla protezione dei dati “GDPR”), si
precisa che ogni circostanza inerente alla presente email (il suo
contenuto, gli eventuali allegati, etc.) è un dato la cui conoscenza è
riservata al/i solo/i destinatario/i indicati dallo scrivente. Se il
messaggio Le è giunto per errore, è tenuta/o a cancellarlo, ogni altra
operazione è illecita. Le sarei comunque grato se potesse darmene notizia.

This email is intended only for the person or entity to which it is
addressed and may contain information that is privileged, confidential or
otherwise protected from disclosure. We remind that - as provided by
European Regulation 2016/679 “GDPR” - copying, dissemination or use of this
e-mail or the information herein by anyone other than the intended
recipient is prohibited. If you have received this email by mistake, please
notify us immediately by telephone or e-mail


On Thu, Jul 11, 2024 at 9:00 AM Kalesse Sören <Soe...@dw...> wrote:

> Hi,
>
> we have a question regarding the fix for
> https://osgeo-org.atlassian.net/browse/GEOS-9757. We are indeed happy
> about this functionality, but we noticed an inconvenience.
>
> We observed that the validation code for vector dimensions creates a
> filter for the particular dimension but wraps it using a ALL_NAMES query,
> which basically results in a query for all features attributes. This
> behavior could result in a lot of feature data to be transferred from the
> backends to GeoServer (probably depending on the store implementation).
>
> On the other hand when querying the data stores for capabilities, the
> queries used there are limited the particular dimension attribute. This
> results in much less data to be transferred from the backends, especially
> if the result is only used to check if it's not empty.
>
> The question would be if the validation code could be improved in such a
> way that it functions similar to the way dimension data for capabilities is
> queried - wrap the filter in a query, but fix the query property to be the
> particular dimension attribute. The org.geoserver.wms.WMS#validateTimes()
> method for example could be adjusted in a way as depicted below (and
> similarly for the validation methods for elevation and custom dimensions):
>
> private void validateTimes(....
> ...
>       Query timeQuery =
>                     getDimensionQuery(
>                             getTimeFilter(explicitTimes, typeInfo,
> builder),
>                             timeInfo,
>
> typeInfo.getFeatureType().getName().getLocalPart());
>             if (DataUtilities.first(fs.getFeatures(timeQuery)) == null) {
>                 throwInvalidDimensionValue(request, ResourceInfo.TIME,
> ResourceInfo.TIME);
>             }
> ...
> }
>
>     /**
>      * wraps the given filter in a query for dimension requests.
>      *
>      * @param filter the filter
>      * @param dimensionInfo the dimension info
>      * @param typeName the feature type name
>      * @return a query that wraps the filter and restricts the query to
> the dimension attribute
>      */
>     private static Query getDimensionQuery(Filter filter, DimensionInfo
> dimensionInfo, String typeName) {
>         final Query dimQuery = new Query(typeName, filter);
>         List<String> propertyNames = new ArrayList<>();
>         propertyNames.add(dimensionInfo.getAttribute());
>         if (dimensionInfo.getEndAttribute() != null &&
> dimensionInfo.getPresentation() != DimensionPresentation.LIST) {
>             propertyNames.add(dimensionInfo.getEndAttribute());
>         }
>         dimQuery.setPropertyNames(propertyNames);
>         return dimQuery;
>     }
>
> Thanks for the help
> Best Regards
>
> Sören
>
>
> _______________________________________________
> Geoserver-users mailing list
>
> Please make sure you read the following two resources before posting to
> this list:
> - Earning your support instead of buying it, but Ian Turton:
> http://www.ianturton.com/talks/foss4g.html#/
> - The GeoServer user list posting guidelines:
> http://geoserver.org/comm/userlist-guidelines.html
>
> If you want to request a feature or an improvement, also see this:
> https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer
>
>
> Geo...@li...
> https://lists.sourceforge.net/lists/listinfo/geoserver-users
>