On 2013-05-13 13:40:57 -0400, Tom Lane wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
> > On Mon, May 13, 2013 at 1:03 PM, Andres Freund <andres@2ndquadrant.com> wrote:
> >> Why don't we just prohibit deletion/modification for anything below
> >> FirstNormalObjectId instead of using the schema as a restriction? Then
> >> we can allow creation for tables as well.
>
> > We currently do, but that led to problems with $SUBJECT.
> AFAIR there are no code restrictions based on OID value. We've got
> restrictions based on things being in pg_catalog or not, and we've got
> restrictions based on things being marked pinned in pg_depend.
> Looking at the OID range might be a reasonable proxy for pinned-ness,
> though, and it would certainly be a lot cheaper than a lookup in
> pg_depend.
It might need a slight change in GetNewObjectId() though: if (IsPostmasterEnvironment) { /* wraparound in
normalenvironment */ ShmemVariableCache->nextOid = FirstNormalObjectId; ShmemVariableCache->oidCount = 0;
} else { /* we may be bootstrapping, so don't enforce the full range */ if
(ShmemVariableCache->nextOid< ((Oid) FirstBootstrapObjectId)) { /* wraparound in standalone
environment?*/ ShmemVariableCache->nextOid = FirstBootstrapObjectId; ShmemVariableCache->oidCount
=0; } }
I think we shouldn't check IsPostmasterEnvironment here but instead
IsBootstrapProcessingMode() since we otherwise can generate oids below
FirstNormalObjectId in --single mode. Imo that should be fixed
independently though, given the comment it looks like either an
oversight or the check predating the existance of
IsBootstrapProcessingMode().
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services