Thread: Is it possible to call other functions inside plpythonu?
Hi folks, Just looking for a nice server side solution to implement some fundamental logic for an application. plpythonu looks in this tmers very well as I'm liking the syntax of Python. However, an very old blog post at [1] made me unsure whether really to use it. Is it still (or has it ever been) an issue that plpythonu is having a lot of overhead and not able to make use of other functions? Didn't found anything on docu for 9.1 about that. Cheers, Frank [1] http://spyced.blogspot.de/2005/04/plpython-intro.html
On Fri, Apr 27, 2012 at 4:42 PM, Frank Lanitz <frank@frank.uvena.de> wrote: > Hi folks, > > Just looking for a nice server side solution to implement some > fundamental logic for an application. plpythonu looks in this tmers very > well as I'm liking the syntax of Python. However, an very old blog post > at [1] made me unsure whether really to use it. Is it still (or has it > ever been) an issue that plpythonu is having a lot of overhead and not > able to make use of other functions? Didn't found anything on docu for > 9.1 about that. There is overhead transforming data to and from types that the Python interpreter can work with. How much overhead is rather subjective - we find it fast enough for the things we use it for. The Python syntax can become a bit cumbersome if you need to interact with the database a lot, in which case plpgSQL is likely the better language for that job. There are counter examples too, where the Python code is much cleaner and in some cases lets you do things impossible in plpgSQL. Access to the Python standard library gives you a great toolkit, and it being 'unsafe' you can do stuff you would otherwise need to write and deploy C extensions for. -- Stuart Bishop <stuart@stuartbishop.net> http://www.stuartbishop.net/
On Fri, May 4, 2012 at 4:09 PM, Stuart Bishop <stuart@stuartbishop.net> wrote:
> On Fri, Apr 27, 2012 at 4:42 PM, Frank Lanitz <frank@frank.uvena.de> wrote:
>> Hi folks,
>>
>> Just looking for a nice server side solution to implement some
>> fundamental logic for an application. plpythonu looks in this tmers very
>> well as I'm liking the syntax of Python. However, an very old blog post
>> at [1] made me unsure whether really to use it. Is it still (or has it
>> ever been) an issue that plpythonu is having a lot of overhead and not
>> able to make use of other functions? Didn't found anything on docu for
>> 9.1 about that.
I forgot to mention that you can (and always have been able to) call
other functions using plpy.execute("SELECT some_func()"). If you need
to invoke Python functions, you can also just 'import' the module like
any other Python code and avoid the overheads of converting data too
and from PostgreSQL data types. You may need to ensure the PYTHONPATH
environment variable gets set correctly if you need to import your own
code from the filesystem rather than the standard library.
--
Stuart Bishop <stuart@stuartbishop.net>
http://www.stuartbishop.net/