On Thu, May 26, 2011 at 6:06 AM, Niels <[email protected]> wrote: > Hi, > > Is there any documentation available on what the filter capabilities are of > the different JDBC data stores, i.e. which functions/operators/etc. are > supported for conversion to SQL expressions? > > This is quite important to know for people who design app-schema mapping > files and filters, because it has a huge effect on performance. But with my > recent joining performance increase tool in app-schema, it is also necessary > to know this to get it actually to work, because the expressions used for > linking features together need to be supported by the filter capabilities to > be able to translate it to join statements.
There is no documentation, you have to look into the filter capabilities classes for the various databases. See for example: modules/plugin/jdbc/jdbc-postgis/src/main/java/org/geotools/data/postgis/FilterToSqlHelper.java modules/plugin/jdbc/jdbc-oracle/src/main/java/org/geotools/data/oracle/OracleFilterToSQL.java modules/plugin/jdbc/jdbc-h2/src/main/java/org/geotools/data/h2/H2FilterToSQL.java Broadly speaking you normally get support for all logic compositionss, non spatial filters, all spatial ones (thought in the case of mysql that support is partial), and arithmetic operations (actually, not so sure about the latter, it seems postgis has that support because it starts from SQLDialect.BASE_DBMS_CAPABILITIES, but other dbs might not). No function whatsoever is supported, by any of the databases, at the moment. Cheers Andrea -- ------------------------------------------------------- Ing. Andrea Aime GeoSolutions S.A.S. Tech lead Via Poggio alle Viti 1187 55054 Massarosa (LU) Italy phone: +39 0584 962313 fax: +39 0584 962313 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.youtube.com/user/GeoSolutionsIT http://www.linkedin.com/in/andreaaime http://twitter.com/geowolf ------------------------------------------------------- ------------------------------------------------------------------------------ vRanger cuts backup time in half-while increasing security. With the market-leading solution for virtual backup and recovery, you get blazing-fast, flexible, and affordable data protection. Download your free trial now. http://p.sf.net/sfu/quest-d2dcopy1 _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
