Re: Caching Python modules

On 17/08/11 14:19, Jan Urbański wrote:
> On 17/08/11 14:09, PostgreSQL - Hans-Jürgen Schönig wrote:
>> CREATE OR REPLACE FUNCTION textprocess.add_to_corpus(lang text, t text) RETURNS float4 AS $$
>>
>>         from SecondCorpus import SecondCorpus
>>         from SecondDocument import SecondDocument
>>
>> i am doing some intense text mining here.
>> the problem is: is it possible to cache those imported modules from function to function call.
>> GD works nicely for variables but can this actually be done with imported modules as well?
>> the import takes around 95% of the total time so it is definitely something which should go away somehow.
>> i have checked the docs but i am not more clever now.
> 
> After a module is imported in a backend, it stays in the interpreter's
> sys.modules dictionary and importing it again will not cause the module
> Python code to be executed.
> 
> As long as you are using the same backend you should be able to call
> add_to_corpus repeatedly and the import statements should take a long
> time only the first time you call them.
> 
> This simple test demonstrates it:
> 
> [example missing the slow() function code]

Oops, forgot to show the CREATE statement of the test function:

postgres=# create or replace function slow() returns void language
plpythonu as $$ import slow $$;

Jan