Hi ne 11. 8. 2024 v 9:23 odesílatel Ayush Vatsa <ayushvatsa1...@gmail.com> napsal:
> Hi PostgreSQL Community, > > I have a scenario where I am working with two functions: one in SQL and > another in C, where the SQL function is a wrapper around C function. Here’s > an example: > > CREATE OR REPLACE FUNCTION my_func(IN input text)RETURNS BIGINT AS $$DECLARE > result BIGINT;BEGIN > SELECT col2 INTO result FROM my_func_extended(input); > RETURN result;END; > $$ LANGUAGE plpgsql; > CREATE OR REPLACE FUNCTION my_func_extended( > IN input text, > OUT col1 text, > OUT col2 BIGINT > )RETURNS SETOF recordAS 'MODULE_PATHNAME', 'my_func_extended'LANGUAGE C > STRICT PARALLEL SAFE; > > I need to prevent direct execution of my_func_extended from psql while > still allowing it to be called from within the wrapper function my_func. > > I’m considering the following options: > > 1. Using GRANT/REVOKE in SQL to manage permissions. > 2. Adding a check in the C function to allow execution only if my_func > is in the call stack (previous parent or something), and otherwise throwing > an error. > > Is there an existing approach to achieve this, or would you recommend a > specific solution? > You can use fmgr hook, and hold some variable as gate if your function my_func_extended can be called https://pgpedia.info/f/fmgr_hook.html With this option, the execution of my_func_extended will be faster, but all other execution will be little bit slower (due overhead of hook). But the code probably will be more simpler than processing callback stack. plpgsql_check uses fmgr hook, and it is working well - just there can be some surprises, when the hook is activated in different order against function's execution, and then the FHET_END can be executed without related FHET_START. Regards Pavel > Best regards, > Ayush Vatsa > AWS >
