On 30.5.2012 22:35, Tom Lane wrote: > Tomas Vondra <t...@fuzzy.cz> writes: >> whenever I run a C-function (part of an .so file) and the file is >> overwritten, the connection crashes. Tested on 9.1.3 and 9.2-beta1. > > "Doctor, it hurts when I do this." > "So don't do that." > > What exactly would you expect Postgres to do about such a thing, anyway? > It has no control over people overwriting its executable files.
Well, I expected the existing connection will use the old .so, while new connections would use the new version (although they're exactly the same). I suppose there are issues with that option too, but crashing the server is a bit unfortunate ... And it actually happens even when the file is overwritten between two queries. I wonder how this affects installing new versions of extensions - does that mean I can't do that while the database is running? Is this mentioned in the docs, somewhere? IMHO there should be a big red banner "DON'T DO THIS" but all I found is this: http://www.postgresql.org/docs/9.1/interactive/xfunc-c.html After it is used for the first time, a dynamically loaded object file is retained in memory. Future calls in the same session to the function(s) in that file will only incur the small overhead of a symbol table lookup. If you need to force a reload of an object file, for example after recompiling it, begin a fresh session. Which kinda looks like my expectation that the session won't crash was correct. Clearly seems like bug to me. Tomas -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
