plpythonu PL/Python - on snake inside elephant

actually we would to something another way around ;) snake inside the elephant, not the other way around like in the little prince story.

good intro can be this talk available on youtube:

followed by it's slides: https://wulczer.org/pywaw-summit.pdf

prelude - what do you need to setup in your postgres?

if you play with plpython3u on fresh postgres instance you will probably need install/setup the following:

apt-get update
apt-get install postgresql-plpython3-11

• be careful to install good version for your postgres version:

inside psql:

CREATE EXTENSION plpython3u;

example fun

create function histogram(a float[], bins int = 10)
returns int[]
as $$
import numpy
return numpy.histogram(a, bins)[0]
$$ language plpython3u;

• you may need install on postgres machine additional python libraries (e.g numpy for above), first install pip: apt-get install python3-pip

Important things to remember:

• keep you functions in separated module with option to mock plpython magic, so these are GOOD tested