GeoInformatics PostGIS 2.0 and writing

GeoInformatics PostGIS 2.0 and writing

时间:2015-07-13 16:36来源:网络整理 作者:KKWL 点击:
Our article about upcoming PostGIS 2.0 just came out recently inGeoInformatics December Issue (issue 8). If you want to know what all the buzz is about with PostGIS 2.0, read the article which starts on page 30. More changes in PostGIS 2.0

Our article about upcoming PostGIS 2.0 just came out recently in GeoInformatics December Issue (issue 8) . If you want to know what all the buzz is about with PostGIS 2.0, read the article which starts on page 30.

More changes in PostGIS 2.0

On another interesting note -- some new changes have happened in PostGIS 2.0. The raster loader is now a regular executable similar to shp2pgsql so no more need for python configuration or python at all. People had a lot of trouble getting the python bindings right to load data. Hopefully this should simplify things. Many thanks to Bborie Park for getting this done before 2.0 release. It was an extremely exciting surprise. Read and see how easy it is. There is also the new ST_GeomFromJSON function which should be a hot addition for web mapping developers. If you are on windows, we have 32-bit experimental builds with all this functionality in the PostGIS Windows experimental downloads section for 8.4-9.1. Note that the experimental binaries don't require any installation, just copy the files into your PostgreSQL install and you are good to go. If you want to do a self-standing portable PostgreSQL which is what we normally do for testing on various PostgreSQL instances - check out our Starting PostgreSQL in windows without install .

What I find most cool about the new raster support is that it's so easy to use without any add-ons because it has all these SQL image export functions. Most of the images we have in the PostGIS 2.0 documentation we created using our make-shift ad-hoc raster/geometry viewers which uses nothing but the PostgreSQL drivers you use in PHP and ASP.Net. We'll be discussing that in an upcoming article. Even though the viewers we created are PHP and ASP.NET, it's just as simple to do in any language say Java and PostgreSQL JDBC driver. Any tool you can use to render saved images in a database, you can take advantage of raster support. I still have in my todo to embed in my reports that require light mapping.

Raster is not just for raster lovers anymore

What most people don't realize about the PostGIS 2.0 raster support is that it enhances the PostGIS geometry support as well. It has functions that allow you to output geometries as raster and overlay them with rasters. This allows you to for example overlay a parcel footprint on top of an aerial image without anything but PostGIS, SQL and your favorite language of choice. We also have ST_Union aggregation functionality for raster which means you can union raster tiles with SQL. You can even clip a raster by a geometry. I'm really very excited about the limitless potential for both standard raster users and geometry-only users that the new raster functionality provides.

Stay tuned for another book from us

We just got another book contract accepted. More on that once things become more final. It is not about PostGIS this time, but PostgreSQL. Yes we are going back to our database roots a bit. We've always thought of ourselves as web application / financials applications / database programmers who accidentally stumbled into the forest of GIS. We hope this new book will be most useful to programmers with not so much experience with databases and PostgreSQL specifically.

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