JTS is LGPL, and is being re licensed to EPL+BSD. On Wed, May 27, 2015 at 6:02 PM Vitali Dyachkov <vit...@arbonaut.com> wrote:
> Hello . > > We completed big project on uDig, GeoTools, PostGIS, H2 and > SymmetricDS. In context of this project we invested into adopting H2 > 1.4 through GeoTools interfaces (H2DataStore) , basically by tuning > gt-jdbc-h2 module , geodb and hatbox libraries. I want to share some > observations first. > > H2 is a great small database which shows excellent performance. Being > integrated into uDig and after all optimization we did it makes > rendering of dozens of thousands of features in multiple layers at the > same time very fast. > > There are several changes that we have done: > > - Usage of VARBINARY data type instead of BLOB. For many reasons BLOB > was not very efficient and became even less efficient in latest H2. > - Changes in SQL generation by FilterToSQL-derived classes and > optimizations for prepared statements > - Declaring most Hatbox and geodb functions as DETERMINISTIC which in > certain scenarios helps to H2 to make right execution plan and avoid > calling functions unnecessarily many times with the same parameters. > - Optimizing hatbox for handling MultiPolygons by splitting them into > parts, requesting spatial index separately and merging results - boost > in performance for MPs in spatial predicates that use spatial index of > Hatbox. > - some minor fixes everywhere. > > > Also H2 database nowadays has built-in GEOMETRY type (based on WKB as a > storage format and JTS for handling it in Java) and even spatial RTree > based index. http://www.h2gis.org guys are developing a wrapping > tier over H2, its built-in geometry type and JTS. In the end JTS is a > driving engine for everything there. But it's GPL and I assume can not > be used as a part of GeoTools library being distributed as GeoTools module. > > I would like to discuss the future of H2 module in GeoTools. I see 2 > options. > > 1) First option is to establish probably a separate module in GT for H2 > 1.4 and using current infrastructure of geodb and hatbox which works > just fine. I would contribute all our results to this module and would > be a maintainer e.g. > > 2) Implement from scratch something similar as H2GIS as , again, a new > GT module with usage of built-in GEOMETRY type and built-in RTree index. > This option should give even better performance because of internal > index utilization comparing with Hatbox (which is a simulation of an > index using normal tables). > > > Regards, > Vitaly. > > > > > > > > > > > > > > > ------------------------------------------------------------------------------ > _______________________________________________ > GeoTools-Devel mailing list > GeoTools-Devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/geotools-devel >
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