Thread: Re: [GENERAL] Image storage questions

I asked this on general, but got no answer on this particular 
point, maybe someone here knows.  Are blobs are stored in the 
shared memory cache upon retrieval?  

I ask because we're trying to decide whether to store an enormous 
number of images in PostgreSQL, and I'd be concerned that 
frequent retrieval of those images would effectively empty the 
cache of the rest of the non-image data.

I watched the pg_statio* numbers during some test retrievals, and 
it appears the reads and cache hits on the binary image data are 
not being counted.  I'm wondering if that is the truth of what's 
going on, or just an accounting oversight.

Thanks.

"Ed L." <pgsql@bluepolka.net> writes:
> I asked this on general, but got no answer on this particular 
> point, maybe someone here knows.  Are blobs are stored in the 
> shared memory cache upon retrieval?  

pg_largeobject is treated exactly the same as any other table,
if that's what you are asking.
        regards, tom lane

On Friday May 20 2005 10:20 am, Tom Lane wrote:
> "Ed L." <pgsql@bluepolka.net> writes:
> > I asked this on general, but got no answer on this
> > particular point, maybe someone here knows.  Are blobs are
> > stored in the shared memory cache upon retrieval?
>
> pg_largeobject is treated exactly the same as any other table,
> if that's what you are asking.

Yes, that was my question.  Are large object rows also vacuumed 
just as the other tables/rows?

Thanks.
Ed