Re: [BUG]Update Toast data failure in logical replication - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: [BUG]Update Toast data failure in logical replication
Date
Msg-id CAA4eK1+md80OOpv39ii6W14ah1gan8SH7zx__qFkNd_Fh6sOhw@mail.gmail.com
Whole thread Raw
In response to Re: [BUG]Update Toast data failure in logical replication  (Dilip Kumar <dilipbalaut@gmail.com>)
Responses RE: [BUG]Update Toast data failure in logical replication  ("tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>)
List pgsql-hackers
On Mon, Feb 7, 2022 at 1:27 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Mon, Feb 7, 2022 at 12:25 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > Attached please find the modified patches.
>
> I have looked into the latest modification and back branch patches and
> they look fine to me.
>

Today, while looking at this patch again, I think I see one problem
with the below change (referring pg10 patch):
+ if (attrnum < 0)
+ {
+ if (attrnum != ObjectIdAttributeNumber &&
+ attrnum != TableOidAttributeNumber)
+ {
+ modified = bms_add_member(modified,
+   attrnum -
+   FirstLowInvalidHeapAttributeNumber);
+ continue;
+ }
+ }
...
...
+ /* No need to check attributes that can't be stored externally. */
+ if (isnull1 || TupleDescAttr(tupdesc, attrnum - 1)->attlen != -1)
+ continue;

I think it is possible that we use TupleDescAttr for system attribute
(in this case ObjectIdAttributeNumber/TableOidAttributeNumber) which
will be wrong as it contains only user attributes, not system
attributes. See comments atop TupleDescData.

I think this check should be modified to  if (attrnum < 0 || isnull1
|| TupleDescAttr(tupdesc, attrnum - 1)->attlen != -1). What do you
think?

* Another minor comment:
+ if (!heap_attr_equals(RelationGetDescr(relation), attrnum, value1,
+   value2, isnull1, isnull2))

I think here we can directly use tupdesc instead of RelationGetDescr(relation).

-- 
With Regards,
Amit Kapila.



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