> On Apr 29, 2026, at 15:15, Bharath Rupireddy
> <[email protected]> wrote:
>
> Hi,
>
> On Tue, Apr 28, 2026 at 8:28 PM shveta malik <[email protected]> wrote:
>>
>> On Wed, Apr 29, 2026 at 7:12 AM Ajin Cherian <[email protected]> wrote:
>>
>>> One small comment. The includes need to be in alphabetical order.
>>> injection_point.h should come after fmgroids.h
>>>
>>> +#include "utils/injection_point.h"
>>> #include "utils/syscache.h"
>>
>> Also there is a trailing whitespace issue while applying the patch.
>> Other than these, the patch looks good.
>
> Fixed. Please find the attached v5 patch.
>
> The fix is needed only for PG16 and later, not PG15 or PG14. The bug
> was introduced by b7ae03953690 [1] in PG16, which added a table_open()
> call in pg_get_publication_tables(). PG15 and earlier only use
> get_rel_namespace() and syscache lookups, both of which gracefully
> handle dropped relations (returning InvalidOid/false rather than
> erroring).
>
> I verified the bug and the fix on all affected branches. Please find
> the attached version-specific patches for backpatching. Thank you!
>
> [1] b7ae03953690 - Ignore dropped and generated columns from the column list
>
> --
> Bharath Rupireddy
> Amazon Web Services: https://aws.amazon.com
> <v5-0001-PG16-Fix-pg_get_publication_tables-race-with-conc.txt><v5-0001-Fix-pg_get_publication_tables-race-with-concurren.patch><v5-0001-PG18-Fix-pg_get_publication_tables-race-with-conc.txt><v5-0001-PG17-Fix-pg_get_publication_tables-race-with-conc.txt>
I am afraid this is only a partial fix.
```
@@ -1599,12 +1621,18 @@ pg_get_publication_tables(FunctionCallInfo fcinfo,
ArrayType *pubnames,
/* Show all columns when the column list is not specified. */
if (nulls[2])
{
- Relation rel = table_open(relid,
AccessShareLock);
+ Relation rel = try_table_open(relid,
AccessShareLock);
int nattnums = 0;
int16 *attnums;
- TupleDesc desc = RelationGetDescr(rel);
+ TupleDesc desc;
int i;
+ /* Skip if the relation has been concurrently dropped.
*/
+ if (rel == NULL)
+ continue;
```
This change uses try_table_open() to detect whether a table has been dropped,
but try_table_open() is only called when the column list is not specified. If a
table is included in the publication with an explicit column list, then even if
it is dropped concurrently, it may still be returned by
pg_get_publication_tables().
So this patch removes the “could not open relation with OID” error, but it does
not fully ensure the accuracy of the returned table list. It also introduces
inconsistent behavior between tables published with and without column lists.
To resolve the race condition completely, I think we should try to open the
table regardless of whether a column list is specified.
Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/
