Entries by Leo Hsu and Regina Obe   

As stated in last article, I've packaged FDW binaries for PostgreSQL 9.4 windows 32-bit and 64-bit and added in the ogr_fdw one. These we've tested with the standard EDB VS built PostgreSQL windows installs and work fine with those.

This christmas I received something very special from Paul Ramsey and Even Roualt as detailed in Foreign Data Wrappers for PostGIS. It's been something I've been patiently waiting for for 4 years. I think it has a few issues I'm working to replicate, but overall it's much faster than I expected and pretty slick.

So why is ogr_fdw so special, because GDAL/OGR is an avenue to many data sources, NOT JUST GEOSPATIAL. It's the NOT JUST that I am most excited about. Though the focus is geospatial you can use it with non-geospatial datasources, as we described a long time ago in OGR2OGR for data loading

Oracle FDW is a foreign data wrapper PostgreSQL extension that allows you to read and write to Oracle database tables from a PostgreSQL database. You can get it via the PGXN network or the main website http://laurenz.github.io/oracle_fdw/.

What is new about the latest 1.1.0 release is that there is now support for the Oracle SDO_GEOMETRY type that allows you to map the most common geometry types POINT, LINE, POLYGON, MULTIPOINT, MULTILINE and MULTIPOLYGON to PostGIS geometry type. Much of the spatial plumbing work was done by Vincent Mora of Oslandia. If we have any Windows Oracle users out there, yes there are binaries available for windows for PostgreSQL 9.1- 9.4 for both 32-bit and 64-bit. The FDW does have a dependency on the OCI.dll which I think comes shipped with Oracle products. Unfortunately, we are not Oracle users so can't kick the tires.

Yesterday was PostGIS day or as some may call it, Post GIS day and a couple of interesting things happened this day:

• PostgreSQL 9.4 RC1 came out.
• There were parties and unconferences, many summarized on http://2014.postgisday.rocks
• I managed to entertain myself with a Conway's game of life PostGIS raster Map algebra style and pondered how wonderful PostGIS would be if it could generate animated gifs with some sort of aggregate function; to which I was politely called crazy by some of my fellow PSC friends.

But what was greatest of all and took the cake were these pictures:

PGDay 2015 San Francisco will be held March 10th 2015 in Hyatt, San Franciso Airport, Burlingame, CA (Just outside of San Francisco). This year PGDay will be hosted along-side Free and Open Source Geospatial North America (FOSS4GNA) conference 2015 which runs March 9th-12th and EclipseCon NA 2015. Speaker submissions for FOSS4GNA 2015 and EclipseCon NA 2015 will end this Monday November 17th, 2014.

At FOSS4G we gave two presentations. The videos from other presentations are FOSS4G 2014 album. I have to commend the organizers for gathering such a rich collection of videos. Most of the videos turned out very well and are also downloadable in MP4 in various resolutions. It really was a treat being able to watch all I missed. I think there are still some videos that will be uploaded soon. As mentioned lots of PostGIS/PostgreSQL talks (or at least people using PostGIS/PostgreSQL in GIS).

If you weren't able to make it to FOSS4G 2014 this year, you can still experience the event Live. All the tracks are being televised live and its pretty good reception. https://2014.foss4g.org/live/. Lots of GIS users using PostGIS and PostgreSQL. People seem to love Node.JS too.

After hearing enough about Node.JS from all these people, and this guy (Bill Dollins), I decided to try this out for myself.

I created a node.js web application - which you can download from here: https://github.com/robe2/node_postgis_express . It's really a spin-off from my other viewers, but more raw. I borrowed the same ideas as Bill, but instead of having a native node Postgres driver, I went for the pure javascript one so its easier to install on all platforms. I also experimented with using base-64 encoding to embed raster output directly into the browser so I don't have to have that silly img src path reference thing to contend with.

For those of you who will be attending either of our PostGIS sessions in Postgres Open 2014 in Chicago September 17th, we've put up a page where we'll be posting links to the data we'll be using as well as the examples so you can follow along and copy and paste. Page is http://www.postgis.us/pgopen2014.

We ask that you bookmark the page before you come and try to install PostGIS 2.1 if you haven't already. Not much to see there yet. For those who haven't signed up, it's not too late. For those who will be unable to make it, we'll try to post all the content from the tutorials on the above page.

A while back, we discussed using pgAdmin pgScript as a quicky way for running a repetitive update script where you want each loop to commit right away. Since stored functions have to commit as a whole, you can't use stored functions alone for this kind of processing.

If you are using the psql client packaged with PostgreSQL 9.3 or above, then you can take advantage of the \watch command that was introduced in that version of psql. We'll demonstrate that by doing a batch geocoding exercise with PostGIS tiger geocoder and also revise our example from the prior article to use the more efficient and terser LATERAL construct introduced in PostgreSQL 9.3.

PostgreSQL 9.4beta1 was released last week and windows binaries for both 32-bit and 64-bit are already available to try it out from http://www.postgresql.org/download/windows. Since this is a beta release, there are no installers yet, just the zip binary archive. To make the pot a little sweeter, we've setup the PostGIS windows build bot (Winnie) to automatically build for 9.4 - PostGIS 2.2.0 development branch and pgRouting 2 branches whenever there is a change in the code. We also have the pointcloud extension in the extras folder. If you are on 9.3, we've got 2.2 binaries for that as well. The PostGIS/pgRouting related stuff you can find at http://postgis.net/windows_downloads in the 9.4 folder.

For the rest of this article we'll discuss a couple of stumbling blocks you may run into.

Much of what we'll describe here is windows specific, but thanks to the beauty of extensions and GUCs, the extension install and GUC setting part for PostGIS is applicable to all operating systems.

I'm not a big proponent of schemaless designs, but they have their place. One particular place where I think they are useful is for archiving of data where even though the underlying table structure of the data you need to archive is changing, you want the archived record to have the same fields as it did back then. This is a case where I think Hstore and the way PostgreSQL has it implemented works pretty nicely.

Side note: one of the new features of PostgreSQL 9.4 is improved GIN indexes (faster and smaller) which is very often used with hstore data (and the new jsonb type). We're really looking forward to the GIN improvements more so than the jsonb feature. We're hoping to test out this improved index functionality with OpenStreetMap data soon and compare with our existing PostgreSQL 9.3. OpenStreetMap pbf and osm extract loaders (osm2pgsql, imposm) provide option for loading tagged data into PostgreSQL hstore fields, in addition to PostGIS geometry and other attribute fields. So 9.4 enhancements should be a nice gift for OSM data users. More on that later.

In this exercise, we'll go thru installing PostgreSQL 9.3 on a CentOS 6 64-bit box. We'll cover upgrading in a later article. For the rest of this article, we'll go over configuring yum to use the PostgreSQL PGDG Yum repository found at http://yum.postgresql.org , which has the latest and greatest of 9.3. It's been a while since we wrote step by step instructions for installing with Yum.

I've read from many that PL/V8 mathematic operations are generally faster than what you get with SQL functions and PL/pgsql functions. One area where I thought this speed would be really useful was for writing Map Algebra call-back functions. A PostGIS 2.1+ map algebra callback function signature looks like: func_name(double precision[][][] value, integer[][] pos, text[] VARIADIC userargs)

One of the features new to PostgreSQL 9.3 is the COPY FROM PROGRAM sql construct and in psql the equivalent \copy from program. Michael Paquier covered the COPY TO/FROM PROGRAM in hist Postgres 9.3 feature highlight: COPY TO/FROM PROGRAM. Depesz covered the companion psql construction in Support for piping copy to from an external program. Michael demonstrated an example using curl. I wanted to try something similar using wget since I have wget readily available on all my Linux and Unix boxes. For this example I'll demonstrate doing it on windows, but doing it on Linux is much the same and simpler since the wget and curl are generally already in Linux default path.

PostGIS 2.1.1 maintenance release was released just yesterday. Details are on the PostGIS.net site: PostGIS 2.1.1 release notes.

For windows users, we have binaries available for PostgreSQL 9.0-9.3 (64-bit) and 9.2-9.3 (32-bit). Which are available in the winnie bot section of download page. We plan to have the windows installers available for 9.2 and 9.3 (both 32 and 64-bit) in the next week or so.