PostGIS developers Dave Blasby and Chris Hodgson will be attending the Ottawa Symposium on GeoSpatial Theory from July 8-11, 2002. If you are attending also, you can find them at the DM Solutions booth on the trade show floor, and ask them all your PostGIS questions. In addition to answering your questions, Dave and Chris will be showing some PostGIS/Mapserver demonstrations and handing out the lovely new PostGIS tri-fold brochures.
The June 2002 issue of Geospatial Solutions magazine includes a column by Jonathan Lowe reviewing open source GIS technology, with some great references to UMN Mapserver and PostGIS/PostgreSQL.
The first group-funded PostGIS development project has committed results to the CVS! Intevation, Imagelinks and Rod Anders of ACM all contributed to the funding of the 7.2 index support project. Chris Hodgson and Dave Blasby of Refractions Research did the work.
The goal of the project was to expedite the support of PostgreSQL 7.2 GiST indexing in PostGIS. The new indexes are more robust (null safe) and allow PostGIS users to take advantage of all the other PostgreSQL 7.2 enhancements in their spatial databases.
The project also included funding to bring out a documented tarball release including the 7.2 indexes and all other enhancements placed in CVS since the 0.6.2 release. The full 0.7 release should be out by May 3rd.
On April 9, 2002, Paul Ramsey gave a presentation at GeoTec2002 on open-source relational databases in a session on open-source GIS technologies. The presentation slides are available (PPT|PPT Japanese).
Version 0.7.1 includes an important bug fix to the spatial indexing and fixes to report compilation problems.
Version 0.7.0 includes two major improvements over the last release:
In addition there have been numerous bug fixes and minor improvements.
The [postgis-users] mailing list has been moved onto the main PostGIS site,along with the online list archives. Subscription information, archives, and searching are all available from the postgis-users page.
The CVS version currently is way ahead of the release version in feature richness. Apologies, but this is because features are being added for consulting projects and we do not have time to do a release and all the accompanying documentation etc.
Reprojection is supported via the PROJ4 library. The SQL function name is transform(<geom>,<srid>). Now you have a reason to populate that SPATIAL_REF_SYS table like you've always wanted. Note however that the SPATIAL_REF_SYS table now requires a PROJ4TEXT column containing the PROJ4 definition string of the spatial reference system.
PostgreSQL 7.2 is currently in beta, and people might be tempted to try to use it with PostGIS 0.6.2. Unfortunately, due to a change in the API hooks for the GiST index, PostGIS 0.6.2 will not work with PostgreSQL 7.2. When PostgreSQL 7.2 is officially released, work on converting PostGIS to support the new indexes will begin. We might drop support for the 7.1 series at that time.
Version 0.6.2 is mostly a bug fix release with fixes for the Shape file loader. There is also a SQL file full of spatial reference definitions to load into the SPATIAL_REF_SYS table.
Astute observers will note the addition of the postgis_chip.c
file. This is the start of support for raster datatypes. There is no
documentation on this because it is still in development and completely
unstable.
The basic idea is that large rasters can be subdivided into smaller chips for storage. The chips will be small enough to fit within the PostgreSQL page size (about 8kb). The chips will be indexable (eventually) and there will be client functions available to retrieve sets of chips and aggregate them into a single image. The result will be random access raster coverages.
