Re: Processes and caches in postgresql

On Wed, Apr 27, 2016 at 7:07 AM, Anastasia Lubennikova
<a(dot)lubennikova(at)postgrespro(dot)ru> wrote:
> Hi, hackers.
> There's a couple of questions about processes.
>
> I found EXEC_BACKEND flag, while reading the code.
> As I understood, it exists because we have to emulate fork() on WIN32.
> And also it allows to debug the same behavior on Linux.
> Is it right? Are there any other use cases?

Right. Or, more precisely, we can't really emulate fork(), so we have
to make due with what's available on Windows, which is basically
exec().

> Another question is about "--fork" argument (see code below).
> I didn't find it in documentation, so I'm a bit confused.
> I wonder if it exists only for internal purposes?

Correct. Just for internal purposes only - definitely not intended
for users to invoke directly.

> And the last, but not least. Do we have any
> presentations/articles/READMEs/whatever
> about caches (src/backend/utils/cache/*) in postgresql?
> I found nothing, besides comments in the code.

Nothing specific comes to mind.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company