Re: cache lookup failed for collation 0

On Thu, Apr 11, 2019 at 10:50 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Jeevan Chalke <jeevan.chalke@enterprisedb.com> writes:
> > Do you mean, the code in get_collation_isdeterministic() should look like
> > something like below?
>
> > If colloid = InvalidOid then
> >   return TRUE
> > ELSE IF tuple is valid then
> >   return collisdeterministic from the tuple
> > ELSE
> >  return FALSE
>
> I think it's appropriate to fail if we don't find a tuple, for any
> collation oid other than zero.  Again, if you trace through the
> behavior of the longstanding collation check functions like
> lc_ctype_is_c(), you'll see that that's what happens (except for
> some hardwired OIDs that they have fast paths for).
>

OK.

Attached patch which treats "collation 0" as deterministic in
get_collation_isdeterministic() and returns true, keeping rest of the code
as is.


>                         regards, tom lane
>


-- 
Jeevan Chalke
Technical Architect, Product Development
EnterpriseDB Corporation
The Enterprise PostgreSQL Company