ne 1. 9. 2019 v 20:48 odesÃlatel David Fetter <da...@fetter.org> napsal:
> On Sun, Sep 01, 2019 at 08:12:15PM +0200, Pavel Stehule wrote: > > Hi > > > > ne 1. 9. 2019 v 20:00 odesÃlatel David Fetter <da...@fetter.org> napsal: > > > > > Folks, > > > > > > I'd like to $Subject, on by default, with a switch to turn it off for > > > those really at the outer edges of performance. Some reasons include: > > > > > > - It's broadly useful. > > > - Right now, the barrier for turning it on is quite high. In addition > > > to being non-core, which is already a pretty high barrier at a lot > > > of organizations, it requires a shared_preload_libraries setting, > > > which is pretty close to untenable in a lot of use cases. > > > - The overhead for most use cases is low compared to the benefit. > > > > > > > I have not a strong opinion about it. pg_stat_statements is really useful > > extenstion, on second hand > > > > 1. the API is not stabilized yet - there are some patches related to this > > extension if I remember correctly > > You do. > > > 2. there are not any numbers what is a overhead > > What numbers would you suggest collecting? We could get some by > running them with the extension loaded and not, although this goes to > your next proposal. > I would to see some benchmarks (pg_bench - readonly, higher number of connects) > > Maybe better solution can be some new API for shared memory, that doesn't > > need to use shared_preload_library. > > What would such an API look like? > possibility to allocate shared large blocks of shared memory without necessity to do it at startup time > > It can be useful for lot of other monitoring extensions, profilers, > > debuggers, > > It would indeed. > > Do you see this new API as a separate project, and if so, of > approximately what size? Are we talking about something about the > size of DSM? Of JIT? > Probably about DSM, and about API how to other processes can connect to some blocks of DSM. I rember similar request related to shared fulltext dictionaries It can be part of some project "enhancing pg_stat_statement - be possible load this extension without restart" > > Best, > David. > -- > David Fetter <david(at)fetter(dot)org> http://fetter.org/ > Phone: +1 415 235 3778 > > Remember to vote! > Consider donating to Postgres: http://www.postgresql.org/about/donate >
