Postgres OnLine Journal     

If you have the OGR_FDW we discussed in OGR FDW Windows first taste built with ODBC support, then you can access most any ODBC datasource from PostgreSQL. This is especially useful for Windows users. Two of the data sources I've been experimenting with are SQL Server and MS Access. In this article, I'll demonstrate how to connect to MS Access with PostgreSQL running on a windows box. I think there is an Access driver for Unix/Linux most robust utilizes java. I won't go there.

One of the foreign data wrappers I included in the PostgreSQL 9.3 Windows FDW bag and PostgreSQL 9.4 Windows FDW bag is the www_fdw extension used for querying web services. Someone asked that since I didn't build curl with SSL support, they are unable to use it with https connections. The main reason I didn't is that the EDB installs come with ssleay32.dll and libeay32.dll (even the 64-bit) which are dependencies of curl when built with SSL support. I wanted to minimize the issue of distributing dlls that are packaged with Windows PostgreSQL installers already.

Though this article is specific to using www_fdw on Windows systems, many of the issues are equally applicable to other platforms, so may be worth a read if you are running into similar issues with using specialty SSL certificates on Linux/Unix/Mac.

One of the changes coming to you in PostGIS 2.2 are additional extensions. Two ones close to my heart are the address_standardizer (which was a separate project before, but folded into PostGIS in upcoming 2.2) and the SFCGAL extension for doing very advanced 3D stuff (was just an sql script in older versions, but made an extension in 2.2 and new functions added). We had a need to have address standardizer running on our Ubuntu box, but since PostGIS 2.2 isn't released yet, you can't get it without some compiling. Luckily the steps are fairly trivial if you are already running PostGIS 2.1. In this article, I'll walk thru just building and installing the address_standardizer extension from the PostGIS 2.2 code base. Though I'm doing this on Ubuntu, the instructions are pretty much the same on any Linux, just replacing with your Linux package manager.

I'm still in the middle of building packages for our clients for the packages that aren't normally distributed for windows to make upgrading to PostgreSQL 9.4 smooth. One of those is PL/V8 which we use for some custom functions. I had mentioned how I build PL/V8 for PostgreSQL windows, and the instructions are a bit out of date., but I put more up to date instructions on my gist page. I tend to use gist a lot as a public scrap book with hopes someone else can learn from my toils and save them some trouble. At some point I should probably get more organized with my scrapbooks.

As stated in last article, I've packaged FDW binaries for PostgreSQL 9.3 windows 32-bit and 64-bit and added in the ogr_fdw one. These we've tested with the standard EDB Vc++ built PostgreSQL windows installs and work fine with those.

This package is an updated list from ones we've distributed before that includes ogr_fdw and recompiled with latests source from www_fdw and file_textarray

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.