Re: Creating a function for exposing memory usage of backend process

torikoshia <torikoshia@oss.nttdata.com>

From: torikoshia <torikoshia@oss.nttdata.com>
To: Fujii Masao <masao.fujii@oss.nttdata.com>
Cc: pgsql-hackers@postgresql.org
Date: 2020-07-03T02:45:52Z
Lists: pgsql-hackers

Attachments

On Wed, Jul 1, 2020 at 10:15 PM torikoshia <torikoshia@oss.nttdata.com> 
wrote:
> I'm going to do some renaming and transportations.
> 
> - view name: pg_memory_contexts
> - function name: pg_get_memory_contexts()
> - source file: mainly src/backend/utils/mmgr/mcxt.c

Attached an updated patch.

On Wed, Jul 1, 2020 at 10:58 PM Fujii Masao 
<masao.fujii@oss.nttdata.com> wrote:
> Ok, understood! I agree that it's strange to display different names
> for the same memory context between this view and logging.
> 
> It's helpful if the comment there refers to MemoryContextStatsPrint()
> and mentions the reason that you told.

Agreed. I changed the comments.

> > It also derived from MemoryContextStatsPrint().
> > I suppose it is for keeping readability of the log..
> 
> Understood. I may want to change the upper limit of query size to 
> display.
> But at the first step, I'm fine with limitting 1024 bytes.

Thanks, I've left it as it was.

> > I'm going to follow the discussion on the mailing list and find why
> > these codes were introduced.
> 
> https://www.postgresql.org/message-id/12319.1521999065%40sss.pgh.pa.us

Thanks for sharing!


Regards,

--
Atsushi Torikoshi
NTT DATA CORPORATION

Commits

  1. Add regression test for pg_backend_memory_contexts.

  2. Move codes for pg_backend_memory_contexts from mmgr/mcxt.c to adt/mcxtfuncs.c.

  3. Prevent non-superusers from reading pg_backend_memory_contexts, by default.

  4. Add pg_backend_memory_contexts system view.

  5. Fix yet another issue with step generation in partition pruning.