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  1. doc: Fix a couple of mistakes in pgplanadvice.sgml

  1. DOCS: pg_plan_advice minor doc fixes

    Lakshmi N <lakshmin.jhs@gmail.com> — 2026-04-08T07:09:23Z

    Hi hackers,

I noticed the following minor discrepancy in the pg_plan_advice docs,
attached a patch to address this.

(1) FOREIGN SCAN should be FOREIGN JOIN in the scan method advice tag. I
tested with FOREIGN SCAN and can confirm it gives a syntax error while the
other one works correctly.

postgres=# SET pg_plan_advice.advice = 'FOREIGN_JOIN((t1 t2))';
EXPLAIN (COSTS OFF, PLAN_ADVICE)
    SELECT * FROM fdw_t1 t1 JOIN fdw_t2 t2 ON t1.id = t2.t1_id;

SET
                   QUERY PLAN
-------------------------------------------------
 Foreign Scan
   Relations: (fdw_t1 t1) INNER JOIN (fdw_t2 t2)
 Supplied Plan Advice:
   FOREIGN_JOIN((t1 t2)) /* matched */
 Generated Plan Advice:
   FOREIGN_JOIN((t1 t2))
   NO_GATHER(t1 t2)
(7 rows)


(2) NESTED_LOOP_MEMOIZE is missing from the join method list in the doc
though it is supported.  Verified this by running below:

postgres=# SET pg_plan_advice.advice = 'NESTED_LOOP_MEMOIZE(d)';
SET
postgres=# EXPLAIN (COSTS OFF, PLAN_ADVICE) select * from t1 f JOIN t2 ON
f.id = t2.t1_id;
                 QUERY PLAN
--------------------------------------------
 Hash Join
   Hash Cond: (t2.t1_id = f.id)
   ->  Seq Scan on t2
   ->  Hash
         ->  Seq Scan on t1 f
 Supplied Plan Advice:
   NESTED_LOOP_MEMOIZE(d) /* not matched */
 Generated Plan Advice:
   JOIN_ORDER(t2 f)
   HASH_JOIN(f)
   SEQ_SCAN(t2 f)
   NO_GATHER(f t2)
(12 rows)

Regards,
Lakshmi

  2. Re: DOCS: pg_plan_advice minor doc fixes

    jie wang <jugierwang@gmail.com> — 2026-04-08T07:52:10Z

    Lakshmi N <lakshmin.jhs@gmail.com> 于2026年4月8日周三 15:09写道：

> Hi hackers,
>
> I noticed the following minor discrepancy in the pg_plan_advice docs,
> attached a patch to address this.
>
> (1) FOREIGN SCAN should be FOREIGN JOIN in the scan method advice tag. I
> tested with FOREIGN SCAN and can confirm it gives a syntax error while the
> other one works correctly.
>
> postgres=# SET pg_plan_advice.advice = 'FOREIGN_JOIN((t1 t2))';
> EXPLAIN (COSTS OFF, PLAN_ADVICE)
>     SELECT * FROM fdw_t1 t1 JOIN fdw_t2 t2 ON t1.id = t2.t1_id;
>
> SET
>                    QUERY PLAN
> -------------------------------------------------
>  Foreign Scan
>    Relations: (fdw_t1 t1) INNER JOIN (fdw_t2 t2)
>  Supplied Plan Advice:
>    FOREIGN_JOIN((t1 t2)) /* matched */
>  Generated Plan Advice:
>    FOREIGN_JOIN((t1 t2))
>    NO_GATHER(t1 t2)
> (7 rows)
>
>
> (2) NESTED_LOOP_MEMOIZE is missing from the join method list in the doc
> though it is supported.  Verified this by running below:
>
> postgres=# SET pg_plan_advice.advice = 'NESTED_LOOP_MEMOIZE(d)';
> SET
> postgres=# EXPLAIN (COSTS OFF, PLAN_ADVICE) select * from t1 f JOIN t2 ON
> f.id = t2.t1_id;
>                  QUERY PLAN
> --------------------------------------------
>  Hash Join
>    Hash Cond: (t2.t1_id = f.id)
>    ->  Seq Scan on t2
>    ->  Hash
>          ->  Seq Scan on t1 f
>  Supplied Plan Advice:
>    NESTED_LOOP_MEMOIZE(d) /* not matched */
>  Generated Plan Advice:
>    JOIN_ORDER(t2 f)
>    HASH_JOIN(f)
>    SEQ_SCAN(t2 f)
>    NO_GATHER(f t2)
> (12 rows)
>
> Regards,
> Lakshmi
>


Hi,

I found that this patch is not fully modified and is missing a part:
`Foreign Scan` --->  `Foreign Join`

Best regards,
--
wang jie

  3. Re: DOCS: pg_plan_advice minor doc fixes

    Lakshmi N <lakshmin.jhs@gmail.com> — 2026-04-09T06:47:48Z

    Hi Jie,

On Wed, Apr 8, 2026 at 12:52 AM jie wang <jugierwang@gmail.com> wrote:

>
>
> Lakshmi N <lakshmin.jhs@gmail.com> 于2026年4月8日周三 15:09写道：
>
>> Hi hackers,
>>
>> I noticed the following minor discrepancy in the pg_plan_advice docs,
>> attached a patch to address this.
>>
>> (1) FOREIGN SCAN should be FOREIGN JOIN in the scan method advice tag. I
>> tested with FOREIGN SCAN and can confirm it gives a syntax error while the
>> other one works correctly.
>>
>> postgres=# SET pg_plan_advice.advice = 'FOREIGN_JOIN((t1 t2))';
>> EXPLAIN (COSTS OFF, PLAN_ADVICE)
>>     SELECT * FROM fdw_t1 t1 JOIN fdw_t2 t2 ON t1.id = t2.t1_id;
>>
>> SET
>>                    QUERY PLAN
>> -------------------------------------------------
>>  Foreign Scan
>>    Relations: (fdw_t1 t1) INNER JOIN (fdw_t2 t2)
>>  Supplied Plan Advice:
>>    FOREIGN_JOIN((t1 t2)) /* matched */
>>  Generated Plan Advice:
>>    FOREIGN_JOIN((t1 t2))
>>    NO_GATHER(t1 t2)
>> (7 rows)
>>
>>
>> (2) NESTED_LOOP_MEMOIZE is missing from the join method list in the doc
>> though it is supported.  Verified this by running below:
>>
>> postgres=# SET pg_plan_advice.advice = 'NESTED_LOOP_MEMOIZE(d)';
>> SET
>> postgres=# EXPLAIN (COSTS OFF, PLAN_ADVICE) select * from t1 f JOIN t2 ON
>> f.id = t2.t1_id;
>>                  QUERY PLAN
>> --------------------------------------------
>>  Hash Join
>>    Hash Cond: (t2.t1_id = f.id)
>>    ->  Seq Scan on t2
>>    ->  Hash
>>          ->  Seq Scan on t1 f
>>  Supplied Plan Advice:
>>    NESTED_LOOP_MEMOIZE(d) /* not matched */
>>  Generated Plan Advice:
>>    JOIN_ORDER(t2 f)
>>    HASH_JOIN(f)
>>    SEQ_SCAN(t2 f)
>>    NO_GATHER(f t2)
>> (12 rows)
>>
>> Regards,
>> Lakshmi
>>
>
>
> Hi,
>
> I found that this patch is not fully modified and is missing a part:
> `Foreign Scan` --->  `Foreign Join`
>

LGTM.

Regards,
Lakshmi

>

  4. Re: DOCS: pg_plan_advice minor doc fixes

    Robert Haas <robertmhaas@gmail.com> — 2026-04-13T16:49:43Z

    On Wed, Apr 8, 2026 at 3:52 AM jie wang <jugierwang@gmail.com> wrote:
> I found that this patch is not fully modified and is missing a part:
> `Foreign Scan` --->  `Foreign Join`

I believe you're wrong about this. EXPLAIN shows "Foreign Scan", not
"Foreign Join".

Committed without this change.

-- 
Robert Haas
EDB: http://www.enterprisedb.com