[PATCH] Resolve unknown-type literals in GRAPH_TABLE COLUMNS

Hi SATYANARAYANA,

On Sun, Apr 26, 2026 at 3:53 AM SATYANARAYANA NARLAPURAM
<satyanarlapuram@gmail.com> wrote:

Hi hackers,

transformRangeGraphTable() calls transformExpr() and
assign_list_collations() for COLUMNS expressions but missed calling
resolveTargetListUnknowns(). As a result, literals such as 'val1'
in a COLUMNS clause retained type "unknown", causing failures with
ORDER BY, UNION, and output conversions.

Fix by calling resolveTargetListUnknowns() on the columns target
list right after assign_list_collations(), similar to SELECT target lists in
transformSelectStmt().

Attached a patch to fix this, which also includes test cases to reproduce.

I can reproduce this and the patch fixes it.

One question: why is resolveTargetListUnknowns called after
assign_list_collations?

I'm asking because in transformSelectStmt, resolveTargetListUnknowns
is invoked before assign_query_collations. It might not matter, but keeping
the order consistent would be good for readers.

Thanks,
Satya

--
Regards
Junwang Zhao

Hi,

On Sun, Apr 26, 2026 at 8:10 AM Junwang Zhao <zhjwpku@gmail.com> wrote:

Hi SATYANARAYANA,

On Sun, Apr 26, 2026 at 3:53 AM SATYANARAYANA NARLAPURAM
<satyanarlapuram@gmail.com> wrote:

Hi hackers,

transformRangeGraphTable() calls transformExpr() and
assign_list_collations() for COLUMNS expressions but missed calling
resolveTargetListUnknowns(). As a result, literals such as 'val1'
in a COLUMNS clause retained type "unknown", causing failures with
ORDER BY, UNION, and output conversions.

Fix by calling resolveTargetListUnknowns() on the columns target
list right after assign_list_collations(), similar to SELECT target

lists in

transformSelectStmt().

Attached a patch to fix this, which also includes test cases to

reproduce.

I can reproduce this and the patch fixes it.

One question: why is resolveTargetListUnknowns called after
assign_list_collations?

I'm asking because in transformSelectStmt, resolveTargetListUnknowns
is invoked before assign_query_collations. It might not matter, but keeping
the order consistent would be good for readers.

Updated the patch. It should be before.

Thanks,
Satya

On Mon, Apr 27, 2026 at 11:34 AM SATYANARAYANA NARLAPURAM
<satyanarlapuram@gmail.com> wrote:

Hi,

On Sun, Apr 26, 2026 at 8:10 AM Junwang Zhao <zhjwpku@gmail.com> wrote:

Hi SATYANARAYANA,

On Sun, Apr 26, 2026 at 3:53 AM SATYANARAYANA NARLAPURAM
<satyanarlapuram@gmail.com> wrote:

Hi hackers,

transformRangeGraphTable() calls transformExpr() and
assign_list_collations() for COLUMNS expressions but missed calling
resolveTargetListUnknowns(). As a result, literals such as 'val1'
in a COLUMNS clause retained type "unknown", causing failures with
ORDER BY, UNION, and output conversions.

Fix by calling resolveTargetListUnknowns() on the columns target
list right after assign_list_collations(), similar to SELECT target lists in
transformSelectStmt().

Attached a patch to fix this, which also includes test cases to reproduce.

I can reproduce this and the patch fixes it.

One question: why is resolveTargetListUnknowns called after
assign_list_collations?

I'm asking because in transformSelectStmt, resolveTargetListUnknowns
is invoked before assign_query_collations. It might not matter, but keeping
the order consistent would be good for readers.

Updated the patch. It should be before.

Do we really need a test for ORDER BY on a literal column? I replaced
all the test queries with a single one which covers all the scenarios
covered by those queries.

The patch needed to consider pstate->p_resolve_unknowns. Unknown
literals are not resolved as text always. See the test query.

--
Best Wishes,
Ashutosh Bapat

On 29.04.26 16:09, Ashutosh Bapat wrote:

On Mon, Apr 27, 2026 at 11:34 AM SATYANARAYANA NARLAPURAM
<satyanarlapuram@gmail.com> wrote:

Hi,

On Sun, Apr 26, 2026 at 8:10 AM Junwang Zhao <zhjwpku@gmail.com> wrote:

Hi SATYANARAYANA,

On Sun, Apr 26, 2026 at 3:53 AM SATYANARAYANA NARLAPURAM
<satyanarlapuram@gmail.com> wrote:

Hi hackers,

transformRangeGraphTable() calls transformExpr() and
assign_list_collations() for COLUMNS expressions but missed calling
resolveTargetListUnknowns(). As a result, literals such as 'val1'
in a COLUMNS clause retained type "unknown", causing failures with
ORDER BY, UNION, and output conversions.

Fix by calling resolveTargetListUnknowns() on the columns target
list right after assign_list_collations(), similar to SELECT target lists in
transformSelectStmt().

Attached a patch to fix this, which also includes test cases to reproduce.

I can reproduce this and the patch fixes it.

One question: why is resolveTargetListUnknowns called after
assign_list_collations?

I'm asking because in transformSelectStmt, resolveTargetListUnknowns
is invoked before assign_query_collations. It might not matter, but keeping
the order consistent would be good for readers.

Updated the patch. It should be before.

Do we really need a test for ORDER BY on a literal column? I replaced
all the test queries with a single one which covers all the scenarios
covered by those queries.

The patch needed to consider pstate->p_resolve_unknowns. Unknown
literals are not resolved as text always. See the test query.

I couldn't find a commit to apply this patch cleanly (the subject says
patch 5/5, so maybe you had some unpublished local changes?). After
applying the test case manually, it looks like the test output is
already correct without the code change. So if this patch is still
required, we need a better test case.

On Mon, May 4, 2026 at 8:42 PM Peter Eisentraut <peter@eisentraut.org> wrote:

On 29.04.26 16:09, Ashutosh Bapat wrote:

On Mon, Apr 27, 2026 at 11:34 AM SATYANARAYANA NARLAPURAM
<satyanarlapuram@gmail.com> wrote:

Hi,

On Sun, Apr 26, 2026 at 8:10 AM Junwang Zhao <zhjwpku@gmail.com> wrote:

Hi SATYANARAYANA,

On Sun, Apr 26, 2026 at 3:53 AM SATYANARAYANA NARLAPURAM
<satyanarlapuram@gmail.com> wrote:

Hi hackers,

transformRangeGraphTable() calls transformExpr() and
assign_list_collations() for COLUMNS expressions but missed calling
resolveTargetListUnknowns(). As a result, literals such as 'val1'
in a COLUMNS clause retained type "unknown", causing failures with
ORDER BY, UNION, and output conversions.

Fix by calling resolveTargetListUnknowns() on the columns target
list right after assign_list_collations(), similar to SELECT target lists in
transformSelectStmt().

Attached a patch to fix this, which also includes test cases to reproduce.

I can reproduce this and the patch fixes it.

One question: why is resolveTargetListUnknowns called after
assign_list_collations?

I'm asking because in transformSelectStmt, resolveTargetListUnknowns
is invoked before assign_query_collations. It might not matter, but keeping
the order consistent would be good for readers.

Updated the patch. It should be before.

Do we really need a test for ORDER BY on a literal column? I replaced
all the test queries with a single one which covers all the scenarios
covered by those queries.

The patch needed to consider pstate->p_resolve_unknowns. Unknown
literals are not resolved as text always. See the test query.

I couldn't find a commit to apply this patch cleanly (the subject says
patch 5/5, so maybe you had some unpublished local changes?).

I am maintaining all the SQL/PGQ fixes in the same branch and creating
patches from that branch. Hence 5/5. But still it shouldn't have
applied cleanly. Both git cherry-pick and git am <attached patch
file>, on a fresh branch succeeded. Please let me know if you still
face the issue.

After
applying the test case manually, it looks like the test output is
already correct without the code change. So if this patch is still
required, we need a better test case.

Yes, the test query doesn't reproduce the bug. Actually all but only
two queries from the Satya's patch show the bug. I have included a
test query which fails, with expected error message, without code
changes now. Also I don't think we need a separate section for this
test query. Included the query in one of the earliest sections in the
file.

--
Best Wishes,
Ashutosh Bapat