Thread: postgres 9.5 create function plpthon3u resets connections to server

On 05/23/2016 11:18 AM, Peter Crosbie wrote:
> this is a repost of a message I mistakenly sent to pgslq-novice,
> although it is probably a simple question
>
> I believe my issue may be that I don't have the correct python
> interpreter on the server's path. I couldn't find
> the required version in the documents and determined what I thought was
> required by using dependency walker
> on the plpython3.dll in postgres lib/.
>
> A pointer to more detailed doc or example would be great. Thanks.
>
> Anyway, here is my issue:
>
> postgresql 9.5 on windows 10, x64.

Where did you get Postgres from and how did you install it?

>
> I have created the extension plpython3u with python 3.3.5 on the
> server's path and it appeared to create the extension successfully:

Can you show how you created the extension?

>
> |SELECT * FROM pg_available_extensions WHERE name like '%python%' order
> by name; name | default_version | installed_version | comment
> -------------------+-----------------+-------------------+------------------------------------------
> - hstore_plpython2u | 1.0 | | transform between hstore and plpython2u
> hstore_plpython3u | 1.0 | | transform between hstore and plpython3u
> hstore_plpythonu | 1.0 | | transform between hstore and plpythonu
> ltree_plpython2u | 1.0 | | transform between ltree and plpython2u
> ltree_plpython3u | 1.0 | | transform between ltree and plpython3u
> ltree_plpythonu | 1.0 | | transform between ltree and plpythonu
> plpython2u | 1.0 | | PL/Python2U untrusted procedural language
> plpython3u | 1.0 | 1.0 | PL/Python3U untrusted procedural language
> plpythonu | 1.0 | | PL/PythonU untrusted procedural language (9 rows) |
>
> However when I attempt to create the following function (from the pg
> docs <http://www.postgresql.org/docs/9.5/static/plpython-funcs.html>)
>
> |CREATE FUNCTION pymax (a integer, b integer) RETURNS integer AS $$ if a
>> b: return a return b $$ LANGUAGE plpython3u; |
>
> the psql (or pgadmin3) terminal's connection is reset.
>
> The python 3.3 on the path is anaconda's distb and runs fine on its own.
> I couldn't find the required version of python in the postgresql docs

The required version will be what ever plpythonu was built against when
the binary was built. At a guess and given what you are seeing that is
not the version in the Anaconda distribution.

> and used dependency walker as described here Postgres database crash
> when installing plpython
> <http://stackoverflow.com/questions/12010344/postgres-database-crash-when-installing-plpython?rq=1> to
> find the required dll that plpython3.dll in the server's lib/ requires.

What is the dependency walker output?

>
> Can anyone help me with what I have missed?
>
> This question is also posted on stackoverflow here
> <https://stackoverflow.com/questions/37382511/postgres-9-5-create-function-plpthon3u-resets-connections-to-server>.
>
> Thanks in advance for your help.
>
> Many thanks
>


--
Adrian Klaver
adrian.klaver@aklaver.com

On 05/23/2016 01:42 PM, Peter Crosbie wrote:
> Adrian, many thanks for picking this up.
>
> Going back to get the link for the installation download, I notice the
> "readme.txt" link next to the installer. Looking at that file for the
> first time, it clearly lays out how to include the language packs
> including plpython. After following the instructions in the readme.txt
> the plpython extension is working fine. No excuse for not reading the
> readme. My bad.
>
> As you note in your response, I was not matching the required version of
> python. The bottom line is that postgresql does seem to be relatively
> sensitive to the particular distribution of python, not just version -
> (I had matched the versions postgres python distb 3.3.4 and anaconda 3.3.4.)

Yes, probably related to how the Python versions where compiled. Also,
from my limited experimentation, the Anaconda Python works best when you
use it with other programs in the Anaconda distribution.

>
> Setting the server's path to use
> C:\EnterpriseDB\LanguagePack\9.5\x64\Python-3.3 as described in the
> readme.txt on the download site was all that it took to get it working
> correctly.
>
> Thanks again picking this up and getting me pointed in the right direction.
>
> For completeness, here are the answers to your specific questions.

Thanks for this, it will help anyone else that goes down the same path.

>
> Where did you get Postgres from and how did you install it?
>
>     postgresql-9.5.3-1-windows-x64.exe from here
>     <http://www.enterprisedb.com/products-services-training/pgdownload#windows>.
>
>
> Can you show how you created the extension?
>
>     CREATE EXTENSION plpython3u;
>
> The required version will be what ever plpythonu was built against when
> the binary was built. At a guess and given what you are seeing that is
> not the version in the Anaconda distribution.
>
>     Agreed and that is indeed the issue, as noted above in the fix.
>
> What is the dependency walker output?
>
>     ... snip
>
>     [  6] PLPYTHON3.DLL
>          [ ? ] LIBINTL-8.DLL
>          [ ? ] PYTHON33.DLL
>          [ ? ] POSTGRES.EXE
>          [  6] MSVCR120.DLL
>               [ ^6] KERNEL32.DLL
>                    [F^6] NTDLL.DLL
>
>
>


--
Adrian Klaver
adrian.klaver@aklaver.com