"Cache lookup failed for relation 16905" ??

Steve Howe <howe@carcass.dhs.org> writes:

I got a weird behavior testing PostgreSQL 7.3b3. The query below was
run in a FreeBSD 4.4 system, on a fresh install and just I just had
made an initb. No classes created at all.

howe=# select p.oid, n.nspname, pg_get_userbyid(p.proowner), proname
from pg_proc as p, pg_namespace as n where pg_table_is_visible(p.oid);
ERROR: Cache lookup failed for relation 16905
ERROR: Cache lookup failed for relation 16905

I think you want pg_function_is_visible, not pg_table_is_visible.

However this does show that the foo_is_visible functions aren't reacting
very nicely when given bad input: they all put out a "Cache lookup
failed" message, rather than something more easily interpretable.

I'm not quite sure what should happen when foo_is_visible is called with
an OID that is not the OID of any foo object; should it quietly return
false, or should it raise a "no such object" error?

regards, tom lane

Hello Tom,

Saturday, November 2, 2002, 11:26:56 AM, you wrote:

TL> Steve Howe <howe@carcass.dhs.org> writes:

I got a weird behavior testing PostgreSQL 7.3b3. The query below was
run in a FreeBSD 4.4 system, on a fresh install and just I just had
made an initb. No classes created at all.

howe=# select p.oid, n.nspname, pg_get_userbyid(p.proowner), proname
from pg_proc as p, pg_namespace as n where pg_table_is_visible(p.oid);
ERROR: Cache lookup failed for relation 16905
ERROR: Cache lookup failed for relation 16905

TL> I think you want pg_function_is_visible, not pg_table_is_visible.
Oh, you are totally right, I got distracted late in the work. I wanted
pg_function_is_visible().

TL> However this does show that the foo_is_visible functions aren't reacting
TL> very nicely when given bad input: they all put out a "Cache lookup
TL> failed" message, rather than something more easily interpretable.
Yes, it confused me, even if the mistake was mine.

TL> I'm not quite sure what should happen when foo_is_visible is called with
TL> an OID that is not the OID of any foo object; should it quietly return
TL> false, or should it raise a "no such object" error?
My opinion is that if should just return false... one can test if the
object exists easily, if he/she needs it (WHERE p.oid in (select oid
from pg_proc)).

However, this situation lead me into another issue. The new conversion
functions (utf8_to_big5, iso_to_alt, etc.) appear as listed in every
new scheme. Is this correct ? Shouldn't them be listed only in
pg_catalog?

How can I distinguish user-defined functions from catalog
(pre-defined) functions ?

-------------
Best regards,
Steve Howe mailto:howe@carcass.dhs.org

Steve Howe <howe@carcass.dhs.org> writes:

howe=# select p.oid, n.nspname, pg_get_userbyid(p.proowner), proname
from pg_proc as p, pg_namespace as n where pg_table_is_visible(p.oid);

However, this situation lead me into another issue. The new conversion
functions (utf8_to_big5, iso_to_alt, etc.) appear as listed in every
new scheme. Is this correct ? Shouldn't them be listed only in
pg_catalog?

They would be, if you had remembered the join condition ;-)

where ... and p.pronamespace = n.oid

regards, tom lane

Hello Tom,

Saturday, November 2, 2002, 5:17:29 PM, you wrote:

TL> Steve Howe <howe@carcass.dhs.org> writes:

howe=# select p.oid, n.nspname, pg_get_userbyid(p.proowner), proname
from pg_proc as p, pg_namespace as n where pg_table_is_visible(p.oid);

However, this situation lead me into another issue. The new conversion
functions (utf8_to_big5, iso_to_alt, etc.) appear as listed in every
new scheme. Is this correct ? Shouldn't them be listed only in
pg_catalog?

TL> They would be, if you had remembered the join condition ;-)
Oh, hehe. It worked, thank you.
I remembered to include the condition on the other metadata queries,
but forgot this one.

Btw I wanted to thank you Tom and Bruce for the "HACKERS] 7.3 gotchas
for applications and client libraries" post, it really helped a lot.
And also for solving the issues on the returned info on INSTEAD rule
queries... thanks.

-------------
Best regards,
Steve Howe mailto:howe@carcass.dhs.org