PostGIS: Difference between revisions

From Wildsong
Jump to navigationJump to search
Brian Wilson (talk | contribs)
Brian Wilson (talk | contribs)
 
(151 intermediate revisions by the same user not shown)
Line 1: Line 1:
PostGIS spatially enables the [[PostgreSQL]] open source DBMS
PostGIS is an extension for [[PostgreSQL]] that spatially enables databases.


Goals:
Currently I am going to do an install on Bellman (no Docker) for performance reasons. The database will run natively. Other services like GeoServer will still be Dockerized for convenience.


1. I am trying to build a GIS data warehouse with a catalog that can be queried in many different ways.
For my day job, I work with ESRI software. I used to be a pariah because I also used PostGIS/PostgreSQL. Those days are over,
now you can go to ESRI for help with installing it, ESRI even uses PostgreSQL inside their Datastore component; times change.


2. I want to have a rich suite of spatial tools available to operate on the data in the warehouse.
== PostGIS on Bellman (Ubuntu Server 20.4) ==


== Building an enterprise geodatabase server ==
# Install PostgreSQL
# Install PostGIS 3.1.1


=== The hardware ===
I will try using [https://wiki.ubuntu.com/UbuntuGIS UbuntuGIS] because that's the simplest approach and they appear to have the latest PostGIS in their archive. This is what I did.


Three platforms. At home, a little Atom-based server running Ubuntu. At work, a spiffy Intel i7/RAID 5 box running Debian 6. On the Internet, a virtual machine at Tektonic.net called a VPS (Virtual Private Server)
sudo apt-get install software-properties-common
sudo add-apt-repository ppa:ubuntugis/ppa
sudo apt update
sudo apt install postgis


It turns out the Atom and Tektonic servers do not have enough RAM to do this job.
...and then I waited... It installed postgis 3.1.1 on top of postgresql 12, in about ''2 minutes''. No big deal.


I am upgrading the Atom server to an AMD-350 motherboard with 8 GB of RAM
I will put pgadmin, geoserver and geowebcache in dockers though.


=== The software ===
== PostGIS on CC-Testmaps (Debian 10) for use with ESRI ArcGIS Enterprise ==


Operating system: Ubuntu Server 10.04 and Debian 6
Start off by realizing that there is an st_geometry.so file you'll need and that it's available only for an older version of PostgreSQL.
I am installing for both PostGIS 1.5 (so I can use [[pgMap]]
You can find it nestled in the desktop software near C:/Program Files (x86)/ArcGIS/Desktop/DatabaseSupport/
and PostGIS 2.0 (so I can use rasters)
and in the Windows server at C:/Program Files/ArcGIS/Server/DatabaseSupport/PostgreSQL/12/Linux64


==== PostgreSQL ====
Be amused they are different versions of the file, the one in Server is probably newer since it's 10.9 and Desktop is 10.8.1.
Find further amusement in the fact that there is no Postgres corresponding support file in Pro 2.8 even though there is a
Resources/DatabaseSupport/ folder.


I ended up building PostgreSQL from source because binaries of 9.0 don't have the development headers so PostGIS can't be built! Foo.
Following the pattern for Ubuntu, how about [https://wiki.debian.org/DebianGis Debian GIS] ?? Well, it's just Debian.
So, the real question is, are Postgres and PostGIS new enough? I need Postgresql 12+ and PostGIS 3+.
As usual, they lag behind so they are at Postgresql 11 and PostGIS 2.5.


sudo apt-get install python-dev libreadline-dev
I am going the PostgreSQL route with
./configure --with-python
make && make install


  This installs into /usr/local, so the scripts have to be adjusted accordingly.
  wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
echo "deb http://apt.postgresql.org/pub/repos/apt/ `lsb_release -cs`-pgdg main" |sudo tee  /etc/apt/sources.list.d/pgdg.list
apt install postgresql-12-postgis-3


I create a script in /etc/profile.d/postgresql.sh to set PATH etc. like this
That gets everything up and running and I can connect as user "postgres" with "psql postgres".


<pre>
=== ArcGIS Desktop ===
# Localization for PostgreSQL and PostGIS -----
###############################################################3
# POSTGRESQL


PGHOME=/usr/local/pgsql
https://desktop.arcgis.com/en/arcmap/latest/manage-data/gdbs-in-postgresql/database-requirements-postgresql.htm
export PGBIN=$PGHOME/bin
export PGLIB=$PGHOME/lib
export PGDATA=/var/lib/postgresql/data
export PGPORT=5432


# I wonder what this does. Same as mv -i option maybe.
Today it says "minimum requirements" include "PostgreSQL 9.6.3 (64 bit) + PostGIS 2.3" and it says
export PGOPTS="-i"
"newer minor versions are supported, but are not certified."


PATH=$PATH:$PGBIN
I tried to get the FME "Data Interoperability" extension working. I was able to create an ETL tool, but it went off a cliff then complaining that I did not have a license. (I actually did when I ran this test.)
export LD_LIBRARY_PATH=$PGLIB


###############################################################3
If you have a commercial license it's the standard $2500 extra. It comes with the personal and non-profit versions.
# POSTGIS


##
The FME model is ETL -- extract data from native format (PostGIS in this case), transform to ESRI format, load it into an ESRI database.
export PATH
All this duplication and copying misses the point of using a database in the first place. And also it means GDAL works fine for the same process. QGIS works even better since it lets me use the native formats directly with no commotion.
</pre>


Once you have installed and sourced the above script then you should be able to run the following commands without having to specify the location for pg_config.
== Vector Tiles ==


Built from source
I made a note to check this guy's article: [https://www.zimmi.cz/posts/2017/postgis-as-a-mapbox-vector-tiles-generator/ PostGIS as a MapBox Vector Tile Generator]
Postgis 1.5.3
so I did, it's about PostGIS 2.4 so only a bit dated now. See this for news: https://info.crunchydata.com/blog/waiting-for-postgis-3-st_asmvt-performance
Postgis 2.0
Proj 4.7.1 (potential conflict with PostGIS 1.5.3)
GDAL 1.8.0
GEOS 3.3.1
Might need source for openjpeg and kml


==== GEOS ====
== PostGIS in Docker ==


GEOS (installed into /usr/local):
I use Docker Compose to put together PostGIS and Geoserver.
sudo apt-get install swig php5-dev phpunit
I document it in the [[Geoserver]] page.
./configure --enable-python --enable-php
 
make && sudo make install
It looks like I will be doing more work with building my own PostGIS docker container to get support for the latest versions.
I am leaving some notes on building from source here.
 
=== Building PostGIS 3 on the efforts of others ===
 
PostGIS repo: https://git.osgeo.org/gitea/postgis/postgis
 
The official build environment, owned by postgis account at hub, account created by Sandro
https://hub.docker.com/r/postgis/postgis-build-env
 
Looks like the github for this image is here: https://github.com/postgis/postgis-build-env
 
At OSGEO "Docker images for PostGIS", from Sandro
https://git.osgeo.org/gitea/postgis/postgis-docker
 
Another one
https://github.com/mattyb/docker-postgis-dev


==== GDAL ====
==== GDAL ====


I always seem to end up wanting features not yet released (ESRI FGDB in this case.) So install the subversion source code to get version 1.9.
Building GDAL is the most convoluted and time consuming step in installing PostGIS from sources.
But it also gives you the best support for the files you need to use, and it is probably necessary
if you want the newest version of PostGIS.
 
'''TODO''' might want to add SFCGAL support but I don't need it yet.
 
sudo apt install postgresql-server-dev-9.6
sudo apt install python-cxx-dev
 
I always need features not yet released in packaged form, so install the subversion source code to track the latest.
 
Get GDAL sources for example
 
cd ~/src/GIS
wget http://download.osgeo.org/gdal/2.2.4/gdal-2.2.4.tar.gz


GDAL (installed into /usr/local):
"poppler" packages are included for PDF support.
"poppler" packages are included for PDF support.
sudo apt-get install openjpeg-tools libopenjpeg-dev
sudo apt-get install libpoppler5 libpoppler-dev
sudo apt-get install expat libexpat1-dev libkml-dev libxerces
sudo apt-get install libcurl4-openssl-dev


I am adding ESRI file geodatabase (version 10 only) support
sudo apt install libopenjp2-7 libopenjp2-7-dev
and ESRI personal geodatabase support (MDB)
sudo apt install libpoppler-dev
   
sudo apt install expat libexpat1-dev libkml-dev libxerces-c-dev
Download kit from http://resources.arcgis.com/content/geodatabases/10.0/file-gdb-download
sudo apt install libcurl4-openssl-dev
sudo apt install libsqlite3-dev
 
'''ESRI FGDB support''': OpenFGDB gives access to version 9 fgdb files and read only, ESRI library only gives version 10 access and write access.
If you want it anyway, download it from ESRI and unpack it.
They move it around, everytime I need it it's in a new place. Try http://appsforms.esri.com/products/download/
 
cd ~/src/GIS
tar xzvf FileGDB_API_1_4-64.tar.gz
cd FileGDB_API
sudo cp lib/*.so /usr/local/lib
sudo ldconfig -v
 
'''ESRI MDB support:''' Who cares? Personal geodatabases are so rare these days I no longer bother to include this.
See http://www.gdal.org/ogr/drv_mdb.html
Install a Java JDK (I use version 7) and get the jackess library: http://jackcess.sourceforge.net/ and put it in this MDB folder
 
mkdir MDB
cd MDB
  wget http://apache.deathculture.net//commons/lang/binaries/commons-lang3-3.1-bin.tar.gz
wget http://apache.cs.utah.edu//commons/logging/binaries/commons-logging-1.1.1-bin.tar.gz
wget http://downloads.sourceforge.net/project/jackcess/jackcess/1.2.9/jackcess-1.2.9.jar?r=http%3A%2F%2Fsourceforge.net%2Fprojects%2Fjackcess%2Ffiles%2F&ts=1355080366&use_mirror=superb-dca3
tar xzvf commons-lang3-3.1-bin.tar.gz
tar xzvf commons-logging-1.1.1-bin.tar.gz
sudo cp commons-logging-1.1.1/commons-logging-1.1.1.jar commons-lang3-3.1/commons-lang3-3.1.jar jackcess-1.2.9.jar /opt/oracle/jdk1.7.0_09/jre/lib/ext/
 
Do the configure and build.


  tar xzvf FileGDB_API_1_1-64.tar.gz
  cd ~/src/GIS/gdal
sudo apt-get install subversion
svn checkout https://svn.osgeo.org/gdal/trunk/gdal gdal
cd gdal
  ./configure \
  ./configure \
  --with-python --with-poppler \
  --with-python --with-poppler \
  --with-pg \
  --with-pg=/usr/bin/pg_config \
  --with-curl \
  --with-curl \
  --with-openjpeg --with-geos --with-geotiff \
  --with-openjpeg --with-geos --with-geotiff \
  --with-jpeg --with-png \
  --with-jpeg --with-png \
  --with-expat --with-libkml --with-xerces-c \
  --with-expat --with-libkml --with-xerces-c
--with-mrsid=/home/bwilson/src/GIS/MrSID/Raster_DSDK \
--with-fgdb=/home/bwilson/src/GIS/FileGDB_API \
--with-java=/usr/local/java/jdk1.7.0_01 --with-mdb
make && sudo make install
gdalinfo --formats ''# confirm the formats you need are listed''
ogrinfo --formats ''# confirm the formats you need are listed''


Note the MrSID and ESRI lines require a complete path for some reason.
Optionally add
Probably my fault, a relative path should be good enough.
--with-java=/opt/oracle/jdk1.7.0_75
--with-fgdb=/home/bwilson/src/GIS/FileGDB_API-64
--with-mrsid=/home/bwilson/src/GIS/MrSID/Raster_DSDK


==== PostGIS ====
Note the MrSID line requires a complete path for some reason. I don't use MrSID so I don't build it in right now. (2017-02)
Probably my fault somehow, I think a relative path should be good enough.


Ordinarily it is handy to do something like this, but this gets too much!
Once configure is done make sure the options you selected show 'yes'. Else adjust and repeat...
# sudo apt-get build-dep postgis


It pulls in many libraries that we want to build from source, to get the latest.
make -j 14
So I pull in only the packages that I need.
sudo make install
sudo ldconfig -v


  sudo apt-get install libxml2-dev
'''Confirm that the version you just built is really the one found.'''
  cd src/GIS/
(There might be an older version for example in /usr/bin! Surprise!!)
  wget http://www.postgis.org/download/postgis-1.5.3.tar.gz
 
  tar xzvf postgis-1.5.3.tar.gz
  gdalinfo --version
  cd postgis-1.5.3
 
./configure --with-pgconfig=/usr/local/pgsql/bin/pg_config --with-geosconfig=/usr/local/bin/geos-config
'''Confirm the formats you need are listed with these commands'''
  make
 
  sudo make install
gdalinfo --formats
  ogrinfo --formats
 
For example.
  ogrinfo --formats | grep GDB
  -> "FileGDB" (read/write)
 
'''Confirm you can load it from Python, too.'''
 
$ '''python'''
Python 2.7.13 (default, Nov 24 2017, 17:33:09)
[GCC 6.3.0 20170516] on linux2
Type "help", "copyright", "credits" or "license" for more information.
  >>> '''import osgeo.gdal'''
>>> '''print osgeo.gdal.__version__'''
2.20dev
  >>>
YAY!
 
=== PostGIS ===
 
==== Installing the prerequisites ====
 
'''Don't do this''': sudo apt-get build-dep postgis
 
Ordinarily it is handy to do something like this to pick up all the build dependencies, but this downloads and installs too much!
 
It picks up binaries that we want to build from source which is bad because we want to get the most up-to-date versions. Then you have to wrestle with having 2 versions of various things (some in /usr and some in /usr/local) and it's too much work.
 
Instead I install the supporting package individually.
I have already installed PostgreSQL and GEOS at this point so
all I needed to do at this stage was this:
 
  sudo apt-get install libxml2-dev libjson-c-dev libproj-dev
 
The PostGIS trunk wants the latest unreleased GEOS.
As long as I am building it, I opt for the python module too.
 
sudo apt install swig
cd ~/src/GIS
git clone https://git.osgeo.org/gitea/geos/geos.git
cd geos
sh autogen.sh
  ./configure --enable-python
  make -j 7


== Server management ==
==== PostGIS 2.4 ====


You have to create the databases etc for Postgres. See the INSTALL file in the sources.
Building from source -- I do it to get features and performance.


  su
  sudo apt-get install xsltproc
adduser postgres
mkdir $PGDATA
chown postgres $PGDATA
su - postgres
initdb -D /usr/local/pgsql/data
exit
/etc/init.d/postgresql-9.0 start
exit
createdb -U postgres test
psql -U postgres test


=== Create user and password for phppgadmin ===
(either) Direct checkout to get the very latest including topology and raster
git clone https://git.osgeo.org/gitea/postgis/postgis
cd postgis
sudo apt install autoconf libtool
sh autogen.sh


From command line... if you want to use database authentication
(or) Do a traditional tarball download to get almost the latest


psql -U postgres
'''Building on Debian and Ubuntu'''
CREATE USER bwilson WITH PASSWORD 'jackalope';
By the time you've made it to this stage the actual PostGIS build seems trivial.


To see the user table
./configure --with-raster
  SELECT * FROM pg_authid;
make -j 10
  sudo make install


Now user bwilson should be able to use phppgadmin
'''Building on Mac''' seemed promising but I failed. I use a Linux virtual machine for testing.


== Install Template ==
== Server management ==


Adding a template makes it much easier to create Postgis databases.
You have to create the initial databases for Postgres. See the INSTALL file in the sources for more information. Here is how I do it.
Refer to PostGIS in Action Appendix B p424
Once the template is installed you can easily create a PostGIS database:


createdb -U postgres my_gisdb -W -T template_postgis
Create a user to own the postgres files


or
su
adduser postgres


echo "CREATE DATABASE my_gisdb WITH TEMPLATE=template_postgis" | psql -U postgis
Create your data storage area(s) (what's the Postgres term for that? it's a "cluster".) This assumes you set PGDATA correctly for your system.


You should be able to do this now:
mkdir $PGDATA
chown postgres $PGDATA


'''psql -U postgres'''
Create the initial database tables
# '''\c my_gisdb'''
# '''SELECT postgis_full_version();'''
  POSTGIS="1.5.3" GEOS="3.3.1-CAPI-1.7.1" PROJ="Rel. 4.7.1, 23 September 2009" LI
BXML="2.7.6" USE_STATS


== Loading data into PostGIS ==
su - postgres
initdb -D $PGDATA
exit


Lots of our data comes in the form of shapefiles, for this I can use
You probably want to edit the $PGDATA/pg_hba.conf and postgresql.conf files.
'''shp2pgsql'''
I add lines to allow my computers to connect in pg_hba.conf and I tell the server to listen for network connections in postgresql.conf


Start the server. There is a sample startup script for Redhat/Centos in the source tree


For ESRI data then I think the best tack is to write a
sudo cp contrib/start-scripts/linux /etc/init.d/postgresql-9
'''geoprocessing Python script''' - It can use the ESRI proprietary code to read any feature class using a cursor and load them into postgis.
sudo systemctl start postgresql


To do this I need to be able to write to the PostGIS database from my Python script.
Create a generic database to test postgres.


I have more extensive notes on loading data here: [[Loading data into PostGIS]]
createdb -U postgres test
psql -U postgres test
\d
\q


=== Load data ===
If it works you can drop it.


With '''shp2pgsql''' command:
dropdb -U postgres test


Convert city polygon shapefile into SQL commands
== Tuning your system for PostGIS ==


shp2pgsql /export/kilchis/temp/Ann/IncidentView/Data/WA/South_King_Fire/AGI_shapefiles/Cities_revised.shp cities > cities.sql
Tips from a SOTM Mapnik doc. http://www.geofabrik.de/media/2010-07-10-rendering-toolchain-performance.pdf


Load the data now by executing the SQL
Adjust settings in your postgresql.conf file


psql -U postgres -d WA_South_King < cities.sql
* shared_buffers 128MB -> 768MB
* work_mem 1MB -> 512MB
* maintenance_work_mem 16 -> 512MB
* fsync on -> off


With gdal '''ogr2ogr''' command, I can reproject while loading:
=== Create another user and password ===


ogr2ogr -f "PostgreSQL" -t_srs 2991 OR_Corvallis Water.shp
From command line... if you want to use database authentication


=== Query data ===
psql -U postgres
CREATE USER gis_owner WITH PASSWORD 'jackalope';


Did the load work? Try a simple query.
To see the user table
SELECT * FROM pg_authid;


'''psql -U postgres -d WA_South_King
== Install PostGIS Template ==
SELECT name FROM cities;'''
      name
------------------
Shoreline
Lake Forest Park
Kenmore
Bothell
...


The glory! Now try a geometric query
'''createdb -U postgres gis_data'''
'''psql -U postgres gis_data'''
# '''CREATE EXTENSION postgis;'''
CREATE EXTENSION
# '''CREATE EXTENSION postgis_topology;'''
CREATE EXTENSION
# '''CREATE EXTENSION address_standardizer;'''
CREATE EXTENSION


'''SELECT name, AREA(the_geom) FROM cities ORDER BY AREA(the_geom);'''
Et voila! You should be able to do this now:
      name      |      area
------------------+------------------
Beaux Arts      | 2308400.44773863
RUSTON          | 7069686.79758783
Hunts Point      | 8537598.97906794
Skykomish        | 9349760.74397126
...


=== Setting the SRID (Spatial reference ID) ===
# '''SELECT postgis_full_version();'''


First I look at the shapefiles to see what the PRJ portion says. Then
and you will see this result or something similar to this:
I look up the SRID in the Proj file /usr/share/proj/esri


Cities is WA North = '''102348''' and Counties is WA South = '''102349'''
POSTGIS="3.1.2 cbe925d" [EXTENSION] PGSQL="130" GEOS="3.7.1-CAPI-1.11.1 27a5e771" PROJ="Rel. 5.2.0, September 15th, 2018" LIBXML="2.9.4" LIBJSON="0.12.1" LIBPROTOBUF="1.3.1" WAGYU="0.5.0 (Internal)" TOPOLOGY
(1 row)


Rivers is Oregon State Lambert (Feet) = '''2992'''
== Some extras ==


NAD_1983_HARN_StatePlane_Oregon_North_FIPS_3601_Feet_Intl = EPSG:2913
Suggestions from the switch2osm page,
(See http://www.ittvis.com/services/Files/envi_pe/envi_pe_v10/EnviPEReferenceDocs/EnviPEProjcsStrings_v10.txt)


New short way
sudo apt-get install munin munin-plugins-extra munin-node iotop ptop


UpdateGeometrySRID([<schema_name>], <table_name>, <column_name>, <srid>)
See also http://aouyar.github.io/PyMunin/plugins/postgresql.html
which I don't have set up yet.


for example,
== Loading data into PostGIS ==
psql -d crbc_spatial
crbc_spatial=> '''SELECT UpdateGeometrySRID('rivers', 'the_geom', 2992);'''
crbc_spatial=>


Long old way
I have moved everything that used to be here to its own page, because this is a pretty big topic. Go look at [[Loading data into PostGIS]]


ALTER TABLE cities DROP CONSTRAINT "enforce_srid_the_geom" RESTRICT;
== Exporting data from PostGIS ==
UPDATE cities SET the_geom=ST_SetSRID(the_geom, 102348);
ALTER TABLE cities ADD CONSTRAINT "enforce_srid_the_geom" CHECK(SRID(the_geom)=102348);
UPDATE geometry_columns set SRID=102348 WHERE f_table_name='cities';


ALTER TABLE WA_Counties DROP CONSTRAINT "enforce_srid_the_geom" RESTRICT;
If you want to go back to a plain old shapefile (the horror!), use
UPDATE wa_counties SET the_geom=ST_SetSRID(the_geom, 102349);
pgsql2shp
ALTER TABLE wa_counties ADD CONSTRAINT "enforce_srid_the_geom" CHECK(SRID(the_geom)=102349);
UPDATE geometry_columns set SRID=102349 WHERE f_table_name='wa_counties';


=== Spatial queries ===
== Accessing data ==


I have also added counties, WA_Counties table. So I can see what cities fall inside King county. The problem is that these tables are now in different projections, so the query fails.
=== ArcMap Desktop ===


SELECT cities.name, WA_Counties.county_nm FROM cities INNER JOIN WA_Counties ON (cities.the_geom && WA_Counties.the_geom AND intersects(cities.the_geom, WA_Counties.the_geom));
See [[ArcGIS + PostGIS]].
ERROR:  Operation on two geometries with different SRIDs


I cannot use the transform() function though because my SPATIAL_REF_SYS table is not loaded with the ESRI values! Que mal!
=== QGIS ===


Use this GDAL util to convert the ESRI codes to Proj.4 codes
QGIS and PostGIS are made for each other, so any guide to QGIS will tell you how to use PostGIS as repository. You can use QGIS to read and write data stored in PostGIS.
cd src/FWTools-2.0.6
export PYTHONPATH=`pwd`/pymod
export LD_LIBRARY_PATH=`pwd`/lib
cd share
../bin/epsg_tr.py -postgis -list esri_extra.wkt > ~/esri.sql


Load them into the database.
=== Web sites ===


su postgres
You can read data directly from PostGIS or you can try using an intermediary. This allows more flexibility. For example you can keep raw spatial data in PostGIS, and create layers in GeoServer complete with styles, and then build up a web map from your own and other services using [[OpenLayers]] or Leaflet.
psql -U postgres -d WA_South_King < /home/AGI/bwilson/esri.sql


Now transform() should work.
I have been working with [[GeoServer]] but many people like [[MapServer]]. There are other choices.


== Reprojection ==
== Reprojection ==
Line 303: Line 364:
  ALTER TABLE wa_counties_p ADD CONSTRAINT "enforce_srid_the_geom"CHECK(SRID(the_geom)=102348);
  ALTER TABLE wa_counties_p ADD CONSTRAINT "enforce_srid_the_geom"CHECK(SRID(the_geom)=102348);


== Exporting data from PostGIS ==
== Additional resources ==
 
pgsql2shp


== Integration with ArcGIS Desktop ==
Postgis wiki http://trac.osgeo.org/postgis/wiki/UsersWikiMain
 
RIP ZigGIS.
See [[SpatialKit]] instead.
 
== Integration with a Web server ==
 
See [[GeoServer]]


== Resources ==
The manual https://postgis.net/docs/manual-dev/
 
Postgis wiki http://trac.osgeo.org/postgis/wiki/UsersWikiMain


An article of interest
An article of interest
Line 324: Line 374:
http://www.bostongis.com/PrinterFriendly.aspx?content_name=sqlserver2008_postgis_mysql_compare
http://www.bostongis.com/PrinterFriendly.aspx?content_name=sqlserver2008_postgis_mysql_compare


== Other ==  
=== Other ===


From some forum or other
From some forum or other
Line 352: Line 402:
explain select * from test limit 1000;
explain select * from test limit 1000;




This will tell you what type of scan is being done. In the above case it is always going to be a sequential scan, due to the nature of the query. If you are doing a query like:
This will tell you what type of scan is being done. In the above case it is always going to be a sequential scan, due to the nature of the query. If you are doing a query like:
Line 389: Line 438:


James"
James"
[[Category:GIS]]
[[Category: OpenLayers]]
[[Category:PostgreSQL]]

Latest revision as of 17:24, 30 June 2021

PostGIS is an extension for PostgreSQL that spatially enables databases.

Currently I am going to do an install on Bellman (no Docker) for performance reasons. The database will run natively. Other services like GeoServer will still be Dockerized for convenience.

For my day job, I work with ESRI software. I used to be a pariah because I also used PostGIS/PostgreSQL. Those days are over, now you can go to ESRI for help with installing it, ESRI even uses PostgreSQL inside their Datastore component; times change.

PostGIS on Bellman (Ubuntu Server 20.4)

  1. Install PostgreSQL
  2. Install PostGIS 3.1.1

I will try using UbuntuGIS because that's the simplest approach and they appear to have the latest PostGIS in their archive. This is what I did.

sudo apt-get install software-properties-common
sudo add-apt-repository ppa:ubuntugis/ppa
sudo apt update
sudo apt install postgis

...and then I waited... It installed postgis 3.1.1 on top of postgresql 12, in about 2 minutes. No big deal.

I will put pgadmin, geoserver and geowebcache in dockers though.

PostGIS on CC-Testmaps (Debian 10) for use with ESRI ArcGIS Enterprise

Start off by realizing that there is an st_geometry.so file you'll need and that it's available only for an older version of PostgreSQL. You can find it nestled in the desktop software near C:/Program Files (x86)/ArcGIS/Desktop/DatabaseSupport/ and in the Windows server at C:/Program Files/ArcGIS/Server/DatabaseSupport/PostgreSQL/12/Linux64

Be amused they are different versions of the file, the one in Server is probably newer since it's 10.9 and Desktop is 10.8.1. Find further amusement in the fact that there is no Postgres corresponding support file in Pro 2.8 even though there is a Resources/DatabaseSupport/ folder.

Following the pattern for Ubuntu, how about Debian GIS ?? Well, it's just Debian. So, the real question is, are Postgres and PostGIS new enough? I need Postgresql 12+ and PostGIS 3+. As usual, they lag behind so they are at Postgresql 11 and PostGIS 2.5.

I am going the PostgreSQL route with

wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
echo "deb http://apt.postgresql.org/pub/repos/apt/ `lsb_release -cs`-pgdg main" |sudo tee  /etc/apt/sources.list.d/pgdg.list
apt install postgresql-12-postgis-3

That gets everything up and running and I can connect as user "postgres" with "psql postgres".

ArcGIS Desktop

https://desktop.arcgis.com/en/arcmap/latest/manage-data/gdbs-in-postgresql/database-requirements-postgresql.htm

Today it says "minimum requirements" include "PostgreSQL 9.6.3 (64 bit) + PostGIS 2.3" and it says "newer minor versions are supported, but are not certified."

I tried to get the FME "Data Interoperability" extension working. I was able to create an ETL tool, but it went off a cliff then complaining that I did not have a license. (I actually did when I ran this test.)

If you have a commercial license it's the standard $2500 extra. It comes with the personal and non-profit versions.

The FME model is ETL -- extract data from native format (PostGIS in this case), transform to ESRI format, load it into an ESRI database. All this duplication and copying misses the point of using a database in the first place. And also it means GDAL works fine for the same process. QGIS works even better since it lets me use the native formats directly with no commotion.

Vector Tiles

I made a note to check this guy's article: PostGIS as a MapBox Vector Tile Generator so I did, it's about PostGIS 2.4 so only a bit dated now. See this for news: https://info.crunchydata.com/blog/waiting-for-postgis-3-st_asmvt-performance

PostGIS in Docker

I use Docker Compose to put together PostGIS and Geoserver. I document it in the Geoserver page.

It looks like I will be doing more work with building my own PostGIS docker container to get support for the latest versions. I am leaving some notes on building from source here.

Building PostGIS 3 on the efforts of others

PostGIS repo: https://git.osgeo.org/gitea/postgis/postgis

The official build environment, owned by postgis account at hub, account created by Sandro https://hub.docker.com/r/postgis/postgis-build-env

Looks like the github for this image is here: https://github.com/postgis/postgis-build-env

At OSGEO "Docker images for PostGIS", from Sandro https://git.osgeo.org/gitea/postgis/postgis-docker

Another one https://github.com/mattyb/docker-postgis-dev

GDAL

Building GDAL is the most convoluted and time consuming step in installing PostGIS from sources. But it also gives you the best support for the files you need to use, and it is probably necessary if you want the newest version of PostGIS.

TODO might want to add SFCGAL support but I don't need it yet.

sudo apt install postgresql-server-dev-9.6
sudo apt install python-cxx-dev

I always need features not yet released in packaged form, so install the subversion source code to track the latest.

Get GDAL sources for example

cd ~/src/GIS
wget http://download.osgeo.org/gdal/2.2.4/gdal-2.2.4.tar.gz

"poppler" packages are included for PDF support.

sudo apt install libopenjp2-7 libopenjp2-7-dev
sudo apt install libpoppler-dev
sudo apt install expat libexpat1-dev libkml-dev libxerces-c-dev
sudo apt install libcurl4-openssl-dev
sudo apt install libsqlite3-dev

ESRI FGDB support: OpenFGDB gives access to version 9 fgdb files and read only, ESRI library only gives version 10 access and write access. If you want it anyway, download it from ESRI and unpack it. They move it around, everytime I need it it's in a new place. Try http://appsforms.esri.com/products/download/

cd ~/src/GIS
tar xzvf FileGDB_API_1_4-64.tar.gz
cd FileGDB_API
sudo cp lib/*.so /usr/local/lib
sudo ldconfig -v

ESRI MDB support: Who cares? Personal geodatabases are so rare these days I no longer bother to include this. See http://www.gdal.org/ogr/drv_mdb.html Install a Java JDK (I use version 7) and get the jackess library: http://jackcess.sourceforge.net/ and put it in this MDB folder

mkdir MDB
cd MDB
wget http://apache.deathculture.net//commons/lang/binaries/commons-lang3-3.1-bin.tar.gz
wget http://apache.cs.utah.edu//commons/logging/binaries/commons-logging-1.1.1-bin.tar.gz
wget http://downloads.sourceforge.net/project/jackcess/jackcess/1.2.9/jackcess-1.2.9.jar?r=http%3A%2F%2Fsourceforge.net%2Fprojects%2Fjackcess%2Ffiles%2F&ts=1355080366&use_mirror=superb-dca3
tar xzvf commons-lang3-3.1-bin.tar.gz 
tar xzvf commons-logging-1.1.1-bin.tar.gz
sudo cp commons-logging-1.1.1/commons-logging-1.1.1.jar commons-lang3-3.1/commons-lang3-3.1.jar jackcess-1.2.9.jar /opt/oracle/jdk1.7.0_09/jre/lib/ext/

Do the configure and build.

cd ~/src/GIS/gdal
./configure \
--with-python --with-poppler \
--with-pg=/usr/bin/pg_config \
--with-curl \
--with-openjpeg --with-geos --with-geotiff \
--with-jpeg --with-png \
--with-expat --with-libkml --with-xerces-c

Optionally add

--with-java=/opt/oracle/jdk1.7.0_75
--with-fgdb=/home/bwilson/src/GIS/FileGDB_API-64
--with-mrsid=/home/bwilson/src/GIS/MrSID/Raster_DSDK

Note the MrSID line requires a complete path for some reason. I don't use MrSID so I don't build it in right now. (2017-02) Probably my fault somehow, I think a relative path should be good enough.

Once configure is done make sure the options you selected show 'yes'. Else adjust and repeat...

make -j 14
sudo make install
sudo ldconfig -v

Confirm that the version you just built is really the one found. (There might be an older version for example in /usr/bin! Surprise!!)

gdalinfo --version

Confirm the formats you need are listed with these commands

gdalinfo --formats
ogrinfo --formats

For example.

ogrinfo --formats | grep GDB
 -> "FileGDB" (read/write)

Confirm you can load it from Python, too.

$ python
Python 2.7.13 (default, Nov 24 2017, 17:33:09) 
[GCC 6.3.0 20170516] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import osgeo.gdal
>>> print osgeo.gdal.__version__
2.20dev
>>> 

YAY!

PostGIS

Installing the prerequisites

Don't do this: sudo apt-get build-dep postgis

Ordinarily it is handy to do something like this to pick up all the build dependencies, but this downloads and installs too much!

It picks up binaries that we want to build from source which is bad because we want to get the most up-to-date versions. Then you have to wrestle with having 2 versions of various things (some in /usr and some in /usr/local) and it's too much work.

Instead I install the supporting package individually. I have already installed PostgreSQL and GEOS at this point so all I needed to do at this stage was this:

sudo apt-get install libxml2-dev libjson-c-dev libproj-dev

The PostGIS trunk wants the latest unreleased GEOS. As long as I am building it, I opt for the python module too.

sudo apt install swig
cd ~/src/GIS
git clone https://git.osgeo.org/gitea/geos/geos.git
cd geos
sh autogen.sh
./configure --enable-python
make -j 7

PostGIS 2.4

Building from source -- I do it to get features and performance.

sudo apt-get install xsltproc

(either) Direct checkout to get the very latest including topology and raster

git clone https://git.osgeo.org/gitea/postgis/postgis
cd postgis
sudo apt install autoconf libtool
sh autogen.sh

(or) Do a traditional tarball download to get almost the latest

Building on Debian and Ubuntu By the time you've made it to this stage the actual PostGIS build seems trivial.

./configure --with-raster
make -j 10
sudo make install

Building on Mac seemed promising but I failed. I use a Linux virtual machine for testing.

Server management

You have to create the initial databases for Postgres. See the INSTALL file in the sources for more information. Here is how I do it.

Create a user to own the postgres files

su
adduser postgres

Create your data storage area(s) (what's the Postgres term for that? it's a "cluster".) This assumes you set PGDATA correctly for your system.

mkdir $PGDATA
chown postgres $PGDATA

Create the initial database tables

su - postgres
initdb -D $PGDATA
exit

You probably want to edit the $PGDATA/pg_hba.conf and postgresql.conf files. I add lines to allow my computers to connect in pg_hba.conf and I tell the server to listen for network connections in postgresql.conf

Start the server. There is a sample startup script for Redhat/Centos in the source tree

sudo cp contrib/start-scripts/linux /etc/init.d/postgresql-9
sudo systemctl start postgresql

Create a generic database to test postgres.

createdb -U postgres test
psql -U postgres test
\d
\q

If it works you can drop it.

dropdb -U postgres test

Tuning your system for PostGIS

Tips from a SOTM Mapnik doc. http://www.geofabrik.de/media/2010-07-10-rendering-toolchain-performance.pdf

Adjust settings in your postgresql.conf file

  • shared_buffers 128MB -> 768MB
  • work_mem 1MB -> 512MB
  • maintenance_work_mem 16 -> 512MB
  • fsync on -> off

Create another user and password

From command line... if you want to use database authentication

psql -U postgres
CREATE USER gis_owner WITH PASSWORD 'jackalope';

To see the user table

SELECT * FROM pg_authid;

Install PostGIS Template

createdb -U postgres gis_data
psql -U postgres gis_data
# CREATE EXTENSION postgis;
CREATE EXTENSION
# CREATE EXTENSION postgis_topology;
CREATE EXTENSION
# CREATE EXTENSION address_standardizer;
CREATE EXTENSION

Et voila! You should be able to do this now:

# SELECT postgis_full_version();

and you will see this result or something similar to this:

POSTGIS="3.1.2 cbe925d" [EXTENSION] PGSQL="130" GEOS="3.7.1-CAPI-1.11.1 27a5e771" PROJ="Rel. 5.2.0, September 15th, 2018" LIBXML="2.9.4" LIBJSON="0.12.1" LIBPROTOBUF="1.3.1" WAGYU="0.5.0 (Internal)" TOPOLOGY
(1 row)

Some extras

Suggestions from the switch2osm page,

sudo apt-get install munin munin-plugins-extra munin-node iotop ptop

See also http://aouyar.github.io/PyMunin/plugins/postgresql.html which I don't have set up yet.

Loading data into PostGIS

I have moved everything that used to be here to its own page, because this is a pretty big topic. Go look at Loading data into PostGIS

Exporting data from PostGIS

If you want to go back to a plain old shapefile (the horror!), use pgsql2shp

Accessing data

ArcMap Desktop

See ArcGIS + PostGIS.

QGIS

QGIS and PostGIS are made for each other, so any guide to QGIS will tell you how to use PostGIS as repository. You can use QGIS to read and write data stored in PostGIS.

Web sites

You can read data directly from PostGIS or you can try using an intermediary. This allows more flexibility. For example you can keep raw spatial data in PostGIS, and create layers in GeoServer complete with styles, and then build up a web map from your own and other services using OpenLayers or Leaflet.

I have been working with GeoServer but many people like MapServer. There are other choices.

Reprojection

CREATE TABLE "wa_counties_p" (gid serial PRIMARY KEY,
"county_cod" int2,"county_fip" varchar(3),"county_nm" varchar(15),
"ecy_region" varchar(4),"air_region" varchar(46));

SELECT AddGeometryColumn(,'wa_counties_s','the_geom','-1','MULTIPOLYGON',2);

ALTER TABLE wa_counties_p DROP CONSTRAINT "enforce_srid_the_geom" RESTRICT;

INSERT INTO wa_counties_p SELECT gid,county_cod, county_fip, county_nm, ecy_region, air_region, transform(the_geom, 102348) FROM wa_counties;

ALTER TABLE wa_counties_p ADD CONSTRAINT "enforce_srid_the_geom"CHECK(SRID(the_geom)=102348);

Additional resources

Postgis wiki http://trac.osgeo.org/postgis/wiki/UsersWikiMain

The manual https://postgis.net/docs/manual-dev/

An article of interest

http://www.bostongis.com/PrinterFriendly.aspx?content_name=sqlserver2008_postgis_mysql_compare

Other

From some forum or other

"574 post(s)

  1. 23-Mar-09 20:06

I suppose I could share a few things that I have found out through trial and error. I am certainly no expert.

I am running on windows server 2003 32 bit, so if you are running 64 bit or *nix versions, the experiences could be very different.

1. Make sure you have the latest version of postgres / postGIS. In another thread you mentioned that you have only just installed it, so I would think that this is the case. Version Postgres 8.3 has a nice easy windows installer that makes it a piece of cake to install. The application Stack Builder picks up the latest postGIS version, so there is no need to worry too much about installing postGIS seperately.

2. I found that installing the Tuning wizard that can be found in the Application Stack Builder helps to configure the memory setting quite well. For my purposes, I didn't need to tweak any of the memory setting into the postgresql.conf file.

3. If you are planning on doing spatial queries on any datasets that you export to postgres, then make sure you have spatial indexes on the geometry field. When you export from manifold using the Postgres type, then these indexes are created automatically. I would suggest reading the postgis user manual, it is pretty comprehensive, and fairly easy to follow. It will give you a good idea of what is possible with spatial queries. It is available http://postgis.refractions.net/download/postgis-1.3.5.pdf

4. The postGIS email list is very helpful. See http://postgis.refractions.net/mailman/listinfo/postgis-users to join.

5. If you are doing joins between tables in the database, then you will have to manually set up the indexes. If you are using pgAdmin III (which I like), then before you run queries, you can see if your indexes are being used by using explain.

--sql (for use within postgresql (or in the database manager console in manifold)


explain select * from test limit 1000;


This will tell you what type of scan is being done. In the above case it is always going to be a sequential scan, due to the nature of the query. If you are doing a query like:

select * from "PARCEL_MAPPING" INNER JOIN "100K index" ON st_intersects("PARCEL_MAPPING".geometry, "100K index".geometry)

where "100K index"."Sheet_Name" = 'DANYO'


There is an explain button in the query editor in pgAdmin III which shows this in a graphic form so you can see pretty quickly if you aren't taking advantage of your indexes.

6. Also as mentioned above, it is a good idea to do vaccuum analyzes often as these help indexes perform better.

7. If you are using large drawings that have lots of drawing objects, then make use of the AOI windowing when linking the drawings. Also see http://forum.manifold.net/forum/t64537.18 for a handy tool to help out.

8. Change the extents() aggregate function in postgres. Manifold uses this when linking drawings (for which reason I don't know). It is VERY slow on large datasets. If you use the tool mentioned above, you don't need the extents function at all. All I did was rename the function so I could still use it if I had to in code and postGIS, but Manifold wasn't automatically trying to use it.

--sql (in postgres)

DROP AGGREGATE extent(geometry);


CREATE AGGREGATE _extent(geometry) (

 SFUNC=public.st_combine_bbox,
 STYPE=box2d

);

That is about all I can think of for the moment, but I am sure others have more tips.

Hope this helps

James"