Concurrent modification of plpgsql function body

Hello all,

I've got an application that keeps a persistent connection into the
database and constantly executes number of stored functions. Sometimes
I need to modify the implementation of those functions to change the
data layout, but doing that results in errors like this:

unrecognized node type: 1852387187

Is it allowed to modify those functions from other connections ?

Thanks!

Best regards,
Alex Vinogradovs