Re: failed runcheck

> Patrick Welche <prlw1@newn.cam.ac.uk> writes:
> > [ core dump due to ]
> > #0  IsSystemRelationName (relname=0x0) at catalog.c:176
> > #1  0x807ed9a in IsSharedSystemRelationName (relname=0x0) at catalog.c:197
> > #2  0x80e9272 in RelationInitLockInfo (relation=0x82af018) at lmgr.c:119
> > #3  0x81202ef in formrdesc (relationName=0x816ad7e "pg_class", natts=22, 
> >     att=0x8173600) at relcache.c:1193
> > #4  0x8120c12 in RelationCacheInitialize () at relcache.c:1953
> 
> and proposes to fix this by having IsSystemRelationName make an
> arbitrary decision about whether a NULL input pointer should be
> considered to represent a system relation name or not.  I do not
> like that, because AFAICS the decision is completely arbitrary.
> IsSystemRelationName shouldn't be called with a NULL pointer
> in the first place, and it has every right to cause a coredump
> if that happens.

I have removed the change.  It will dump core again.

> 
> It looks to me like the immediate bug here is that
> RelationGetPhysicalRelationName is returning a NULL pointer.  Probably
> there are some missing or out-of-order steps in relcache initialization?
> 
> I've been offline for a couple days due to DSL line failure :-( so

That is bad.  Mine has been great, but I had my first DSL burp for 3
hours on Friday after 4 months of continuous uptime.

> I haven't seen Vadim's latest checkins.  But I'm betting this is a bug
> in the changes to use OIDs as physical relnames.  Do we even need
> RelationGetPhysicalRelationName anymore, and if so, what does it mean?

Good bet.

> 
> Next question: why is RelationInitLockInfo using
> RelationGetPhysicalRelationName to get the input data for
> IsSharedSystemRelationName --- shouldn't that be a test on logical
> relation name?  Or maybe the entire premise of
> IsSharedSystemRelationName is bogus now, and we ought to use some other
> way to decide if a relation is cross-database or not?

No, because if they create a temp table that masks a system table in the
current session, you want the physical name so it can know if it is a
real system table, or a temp/fake one.

You can ask why would someone try this, but it will work, or do
something while trying.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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