On 2026-07-20 Mo 2:52 AM, Rafia Sabih wrote:
On Thu, 16 Jul 2026 at 20:02, Andrew Dunstan <[email protected]> wrote:
On Thu, Jul 16, 2026 at 9:37 AM Rafia Sabih
<[email protected]> wrote:
On Thu, 4 Jun 2026 at 04:32, Andrew Dunstan
<[email protected]> wrote:
On 2025-05-26 Mo 7:06 AM, Julien Tachoires wrote:
> On Sat, Mar 29, 2025 at 08:46:01AM +0100, Julien
Tachoires wrote:
>> On Sun, Mar 02, 2025 at 02:23:54PM +0100, Julien
Tachoires wrote:
>>> On Sun, Mar 02, 2025 at 09:56:41AM +0100, Julien
Tachoires wrote:
>>>> With the help of the new TAM routine
'relation_options', table access
>>>> methods can with this patch define their own reloptions
>>>> parser/validator.
>>>>
>>>> These reloptions can be set via the following commands:
>>>> 1. CREATE TABLE ... USING table_am
>>>> WITH (option1='value1', option2='value2');
>>>> 2. ALTER TABLE ...
>>>> SET (option1 'value1', option2 'value2');
>>>> 3. ALTER TABLE ... SET ACCESS METHOD table_am
>>>> OPTIONS (option1 'value1', option2 'value2');
>>>>
>>>> When changing table's access method, the settings
inherited from the
>>>> former TAM can be dropped (if not supported by the
new TAM) via: DROP
>>>> option, or, updated via: SET option 'value'.
>>>>
>>>> Currently, tables using different TAMs than heap are
able to use heap's
>>>> reloptions (fillfactor, toast_tuple_target, etc...).
With this patch
>>>> applied, this is not the case anymore: if the TAM
needs to have access
>>>> to similar settings to heap ones, they have to
explicitly define them.
>>>>
>>>> The 2nd patch file includes a new test module
'dummy_table_am' which
>>>> implements a dummy table access method utilized to
exercise TAM
>>>> reloptions. This test module is strongly based on
what we already have
>>>> in 'dummy_index_am'. 'dummy_table_am' provides a
complete example of TAM
>>>> reloptions definition.
>>>>
>>>> This work is directly derived from SadhuPrasad's
patch here [2]. Others
>>>> attempts were posted here [1] and here [3].
>>>>
>>>> [1]
https://www.postgresql.org/message-id/flat/429fb58fa3218221bb17c7bf9e70e1aa6cfc6b5d.camel%40j-davis.com
>>>> [2]
https://www.postgresql.org/message-id/flat/caff0-cg4kzhdtyhmsonwixnzj16gwzpduxan8yf7pddub+g...@mail.gmail.com
>>>> [3]
https://www.postgresql.org/message-id/flat/AMUA1wBBBxfc3tKRLLdU64rb.1.1683276279979.Hmail.wuhao%40hashdata.cn
>>> Please find a new version including minor fixes: 'TAM'
terms are
>>> replaced by 'table AM'
>> Please find a new rebased version.
> New rebased version.
>
This thread seems to have gone dormant, sadly. Here's a
fresh attempt I
made (with assistance from Claude), before I was aware of
the existence
of this and other efforts. I think it meets most of the
previous
objections, and is in line with what we do for Index AMs.
I was testing this patch and found this issue,
CREATE EXTENSION dummy_table_am;
CREATE TABLE t (a int) USING dummy_table_am WITH (option_int =
42);
ALTER TABLE t SET ACCESS METHOD heap;
SELECT reloptions FROM pg_class WHERE oid = 't'::regclass;
reloptions
-----------------
{option_int=42}
(1 row)
ALTER TABLE t SET (fillfactor = 50);
2026-07-16 19:01:36.060 IST [95058] ERROR: unrecognized
parameter "option_int"
2026-07-16 19:01:36.060 IST [95058] STATEMENT: ALTER TABLE t
SET (fillfactor = 50);
ERROR: unrecognized parameter "option_int"
Basically, the option is left behind after changing the
tableam to heap, I think that isn't intentional.
Thanks for reviewing. Good catch!
Basically the code had an early exit in the validation code that
shouldn't have been there.
v2 attached with a fix for that, plus a regression test covering this
direction (dummy_table_am -> heap with a still-set AM-specific
option),
which I verified fails against v1 and passes with the fix. I also
folded the two independent access-method-resolution code paths in
DefineRelation into one and added the new test module's typedefs to
typedefs.list
I can confirm that on the new patch, the alter command gives error and
the one with the RESET does the job,
ALTER TABLE t SET ACCESS METHOD heap;
2026-07-17 12:55:04.244 IST [55465] ERROR: unrecognized parameter
"option_int"
2026-07-17 12:55:04.244 IST [55465] STATEMENT: ALTER TABLE t SET
ACCESS METHOD heap;
ALTER TABLE t SET ACCESS METHOD heap, RESET(option_int);
ALTER TABLE
However, I encountered another issues now, this time with partitioning,
CREATE TABLE parted(a int) PARTITION BY RANGE(a);
CREATE TABLE parted_p1 PARTITION OF parted for values from (1) to (10)
WITH (option_int=50); 2026-07-20
12:20:54.137 IST [55465] ERROR: unrecognized parameter "option_int"
2026-07-20 12:20:54.137 IST [55465] STATEMENT: CREATE TABLE parted_p1
PARTITION OF parted for values from (1) to (10) WITH (option_int=50);
ERROR: unrecognized parameter "option_int"
So basically partitioned table is not able to read the new reloption.
I think this is a test issue rather than a patch issue. Neither
statement names an access method: "parted" is a plain partitioned table
with no USING, so it falls back to default_table_access_method, i.e.
heap; parted_p1 doesn't override that either. heap has no idea what
option_int is, so the error is correct -- dummy_table_am was never in
the picture for either table.
If I add USING dummy_table_am to the parent, it works as expected:
CREATE TABLE parted(a int) PARTITION BY RANGE(a) USING dummy_table_am;
CREATE TABLE parted_p1 PARTITION OF parted FOR VALUES FROM (1) TO (10)
WITH (option_int=50);
-- CREATE TABLE, no error; reloptions = {option_int=50}
cheers
andrew
--
Andrew Dunstan
EDB:https://www.enterprisedb.com
