Ben, MANY MANY THANKS!!!!!
I've been trawling through the documentation, but hadn't found that bit yet (still a lot to learn!) Now to get a feeling for my options based on performance, i.e. is it better to pack the data from all themes (working on INSPIRE stuff here) into 1 DB to enable joining across themes or saner to disaggregate and forgo the joining benefits thanks for the prompt response! :) Kathi On 24.08.2016 23:47, Ben Caradoc-Davies wrote: > Kathi, > > thank you for your detailed report. I had a look through your mapping > files and they look fine. Your testing proves that they work in a > single database. > > For performance, app-schema converts queries against feature-chained > types from database sources into efficient SQL, referred to as "joining": > http://docs.geoserver.org/latest/en/user/data/app-schema/joining.html > > Joining cannot be used for feature chaining between databases because > an SQL query can only be made against one database at a time. The > evidence implicating joining is the mention in the stack trace of > JoiningNestedAttributeMapping; this class is only used in app-schema > joining. > > Joining is turned on by default. It is automatically turned off when > using non-database sources, but I do not think that app-schema checks > whether chaining is applied between database sources. As noted in the > manual: > > "All feature mappings that are chained to each other must map to the > same physical database." > > and > > "Failing to comply with any of these three restrictions when turning > on Joining will result in exceptions thrown at run-time." > > To turn off app-schema chaining, set "app-schema.joining=false" in > your app-schema.properties or as a JVM argument: > http://docs.geoserver.org/latest/en/user/data/app-schema/joining.html#configuration > > > > Kind regards, > Ben. > > On 24/08/16 22:06, Kathi Schleidt wrote: >> Hi, >> >> In the process of trying to link features from multiple INSPIRE Themes >> via Feature Chaining, I’ve run into difficulties using multiple (well 2) >> databases (was trying to do one database per feature type/namespace). To >> clarify that it’s not a problem with my configuration I put together a >> simple example consisting of a main feature with two nested features, >> one of which should stem from a different DB than the main parts. >> (schema available at http://www.schleidt.org/schemas/test.xsd) >> >> Within the main DB (test2, DataStore idDataStoreTS), there are 2 tables: >> >> * testmain: the main part >> >> * nest: the part that should actually be in the other database >> >> Within the 2^nd DB (nest2, DataStore idDataStoreNS), there is only the >> nest table (identical to the one in test, just different content to see >> where the data is coming from) >> >> The DataStore configuration for both databases is identical except for >> the database name (test2 vs nest2) >> >> As long as I’m only using the main database (test2), everything works >> out beautifully. The moment I try to use the 2^nd database connection >> (nest2), while there are no errors on startup, there are also no >> features, just the following error (for ts:nestExt it should be going >> for the table nest in the db nest2, but it’s complaining about the table >> testmain from the db test2): >> >> java.lang.RuntimeException: Error applying mapping with targetAttribute >> ts:nestExt >> >> Error applying mapping with targetAttribute ts:nestExt >> >> java.io.IOExceptionSchema 'testmain' does not exist. >> >> An interesting aside – when I set up this test, I first forgot to set up >> my db as postgis (I’m an old geek, and spatial is still new to me). This >> worked fine as long as I was only using one DB (there are no geometries >> in my simple example), when I added the 2^nd one I got an interesting >> PostGis error (might help in debugging): >> >> Function postgis_lib_version() doesn’t exist >> >> >> Configuration and logfiles are available at: >> http://www.schleidt.org/kathi/DBProblem.zip >> >> Main problem in the subdirectory PostGisDB, the 2 variants with just >> PostGres are PostGres1 & 2 (for 1 or 2 dbs) >> >> Can somebody tell me if I'm going crazy or if there's a problem here? >> >> :) >> >> Kathi >> >> >> >> ------------------------------------------------------------------------------ >> >> >> >> >> >> _______________________________________________ >> Geoserver-users mailing list >> Geoserver-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/geoserver-users >> > -- _________________________________________________________________________ Katharina Schleidt Tel: +43 (1) 89 234 26 Mobile: +43 (650) 89 234 26 Skype: Kathi Schleidt ka...@schleidt.org www.schleidt.org/kathi The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it - Albert Einstein Growth for the sake of growth is the ideology of the cancer cell – Edward Abbey If at first, the idea is not absurd, then there is no hope for it - Albert Einstein ------------------------------------------------------------------------------ _______________________________________________ Geoserver-users mailing list Geoserver-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geoserver-users
