Re: PostgreSQL Process memory architecture

* Atri Sharma (atri(dot)jiit(at)gmail(dot)com) wrote:
> > Does each PostgreSQL process allocating in its own memory (Not shared
> > memory) a cache of all the database catalog which it access during the SQL
> > execution?

This information is pulled into a backend-local cache, but it should
only be cached while it's needed and then purged out to allow for new
data coming in. It would be great if we could understand what the issue
is that you're seeing.

> > I mean does each process holds all the catalog indexes data which it
> > accessed, all the catalog index statistics etc’ accessed

Each backend shouldn't try to hold all the data, if there is pressure
for that memory.

> AFAIK, the shared disk buffers are the only part shared between the processes.

There's a bit of other information shared, but disk buffers are
certainly the bulk of it.

Thanks,

Stephen