Re: Assertion failure in smgr.c when using pg_prewarm with partitioned tables

On 2025/05/15 18:20, Dilip Kumar wrote:
> On Thu, May 15, 2025 at 2:22 PM Masahiro Ikeda <ikedamsh(at)oss(dot)nttdata(dot)com> wrote:
>>
>> Hi,
>>
>> I encountered an assertion failure when a partitioned table is specified
>> as an argument to pg_prewarm. Below are the steps to reproduce the
>> issue:

Thanks for the report!

This assertion failure can also occur when pg_prewarm() is run on objects like
foreign tables, plain views, or other relations that don't have storage - not just
partitioned tables.

>> $ pgbench -i -s 1 --partitions=3
>> $ psql <<EOF
>> CREATE EXTENSION pg_prewarm;
>> SELECT pg_prewarm('pgbench_accounts');
>> EOF
>>
>> The following assertion failure occurs:
>>
>> TRAP: failed Assert("RelFileNumberIsValid(rlocator.relNumber)"), File:
>> "smgr.c", Line: 246, PID: 1246282
>> postgres: ikeda postgres [local]
>> SELECT(ExceptionalCondition+0xbb)[0x55edd16725c1]
>> postgres: ikeda postgres [local] SELECT(smgropen+0x5e)[0x55edd145c1ff]
>>
>>
>> It looks like this may have been overlooked in commit 049ef33.
>> What do you think?
>
> Yeah, this should be fixed, don't you think that instead of checking
> the relnumber is valid,

+1

How about adding a check to see whether the target relation has storage,
using something like RELKIND_HAS_STORAGE()?

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION