GIN tries to form a tuple with a partial compressedList during insertion

Arseniy Mukhin <arseniy.mukhin.dev@gmail.com>

From: Arseniy Mukhin <arseniy.mukhin.dev@gmail.com>

To: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-04-30T08:40:26Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Avoid unnecessary GinFormTuple() calls for incompressible posting lists.
- 771cfe22a098 19 (unreleased) landed

Attachments

gin_insert_invalid_compressed_list_fix.patch (text/x-patch) patch

Hi,

In the functions addItemPointersToLeafTuple and buildFreshLeafTuple
(in gininsert.c), the result of ginCompressPostingList()
is passed to GinFormTuple without checking whether
ginCompressPostingList() successfully packed all items.
These GinFormTuple calls consistently fail because the resulting
tuples always exceed the maximum size.
While this doesn’t result in data corruption, it might still be worth
addressing.
Additionally, the condition if (compressedList) is unnecessary, since
ginCompressPostingList() never returns NULL.

Please find the attached patch fixing it.

Best regards,
Arseniy Mukhin