BUG #18514: Encountering an error invalid DSA memory alloc request size 1811939328 when executing script

The following bug has been logged on the website:

Bug reference: 18514
Logged by: iwebcas
Email address: iwebcas(at)gmail(dot)com
PostgreSQL version: 16.3
Operating system: Debian 8.3.0-6 (PostgreSQL 16.3)
Description:

Issue Report: Invalid DSA Memory Allocation Request Size

Summary:
Encountering an error invalid DSA memory alloc request size 1811939328 when
executing a prepared statement after multiple runs. The error occurs due to
a different execution plan being chosen on the 6th attempt.

Description:
I have a prepared query that executes successfully using a specific
execution plan for the first five attempts. However, on the 6th execution, a
different plan is chosen, resulting in an error and the query failing.

Steps to Reproduce:

Prepare the query:

sql
PREPARE testQuery (timestamp) AS
SELECT
"SuDocumentOneC"."Id" AS "Id",
"SuDocumentBase"."Id" AS "SuDocumentBase.Id"
FROM
"public"."SuDocumentOneC" "SuDocumentOneC"
LEFT OUTER JOIN "public"."SuDocumentOneC" "SuDocumentBase"
ON ("SuDocumentBase"."Id" = "SuDocumentOneC"."SuDocumentBaseId")
WHERE
("SuDocumentOneC"."ModifiedOn" < $1)
ORDER BY
"Id" ASC NULLS FIRST;
Execute the query multiple times:

sql
Копировать код
EXPLAIN (ANALYZE, BUFFERS) EXECUTE testQuery ('2024-06-05 10:24:39');
EXPLAIN (BUFFERS) EXECUTE testQuery ('2024-06-05 10:24:39');

The query runs correctly the first five times, using the following plan:
sql
Gather Merge (cost=25656.39..47885.28 rows=190520 width=32)
Workers Planned: 2
-> Sort (cost=24656.37..24894.52 rows=95260 width=32)
Sort Key: "SuDocumentOneC"."Id" NULLS FIRST
-> Parallel Hash Left Join (cost=4811.69..15441.97 rows=95260
width=32)
Hash Cond: ("SuDocumentOneC"."SuDocumentBaseId" =
"SuDocumentBase"."Id")
-> Parallel Seq Scan on "SuDocumentOneC" (cost=0.00..8608.22
rows=95260 width=32)
Filter: ("ModifiedOn" < '2024-06-05 10:24:39'::timestamp
without time zone)
-> Parallel Hash (cost=3147.46..3147.46 rows=95698
width=16)
-> Parallel Index Only Scan using
"PKfh5fLg2Fg2F9m8kIjOIQ2e4Rc" on "SuDocumentOneC" "SuDocumentBase"
(cost=0.42..3147.46 rows=95698 width=16)
Planning:
Buffers: shared hit=581

On the 6th attempt, a different execution plan is used, resulting in the
error:
sql
Gather Merge (cost=12352.45..19796.07 rows=63798 width=32)
Workers Planned: 2
-> Sort (cost=11352.43..11432.18 rows=31899 width=32)
Sort Key: "SuDocumentOneC"."Id" NULLS FIRST
-> Parallel Hash Right Join (cost=4945.70..8517.24 rows=31899
width=32)
Hash Cond: ("SuDocumentBase"."Id" =
"SuDocumentOneC"."SuDocumentBaseId")
-> Parallel Index Only Scan using
"PKfh5fLg2Fg2F9m8kIjOIQ2e4Rc" on "SuDocumentOneC" "SuDocumentBase"
(cost=0.42..3147.46 rows=95698 width=16)
-> Parallel Hash (cost=4546.54..4546.54 rows=31899
width=32)
-> Parallel Index Scan using
"IX_SuDocumentOneC_ModifiedOn_V2" on "SuDocumentOneC" (cost=0.42..4546.54
rows=31899 width=32)
Index Cond: ("ModifiedOn" < $1)
Planning:
Buffers: shared hit=34

ERROR: invalid DSA memory alloc request size 1811939328
CONTEXT: parallel worker
SQL state: XX000
System Details:

PostgreSQL version: "PostgreSQL 16.3 (Debian 16.3-1.pgdg100+1) on
x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit"
Version on which the error is not reproduced: "PostgreSQL 16.2 (Debian
16.2-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6)
8.3.0, 64-bit"
Request for Help:
Could you please assist in understanding why the execution plan changes and
how to resolve the error invalid DSA memory alloc request size 1811939328?
Any guidance or recommendations would be greatly appreciated.