Re: A assert failure when initdb with track_commit_timestamp=on - Mailing list pgsql-hackers

Fujii Masao <masao.fujii@oss.nttdata.com> writes:
> On 2025/07/04 16:29, Hayato Kuroda (Fujitsu) wrote:
>> If more GUCs were found which cannot be set during the bootstrap mode, how about
>> introducing a new flag like GUC_DEFAULT_WHILE_BOOTSTRAPPING for GUC variables?
>> If the flag is set all setting can be ignored when
>> IsBootstrapProcessingMode() = true.

> If there are many GUCs that behave incorrectly during bootstrap,
> a general mechanism like that might be worth considering. But if
> only a few GUCs are affected, as I believe is the case,
> then such a mechanism may be overkill.

As I remarked in the other thread, I don't like inventing a different
solution for each GUC.  So if there are even two that need something
done, I think Hayato-san's idea has merit.

The core of the patch could be as little as

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 667df448732..43f289924e6 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -3464,6 +3464,15 @@ set_config_with_handle(const char *name, config_handle *handle,
         return 0;
     }

+    /*
+     * Certain GUCs aren't safe to enable during bootstrap mode.  Silently
+     * ignore attempts to set them to non-default values.
+     */
+    if (unlikely(IsBootstrapProcessingMode()) &&
+        (record->flags & GUC_IGNORE_IN_BOOTSTRAP) &&
+        source != PGC_S_DEFAULT)
+        changeVal = false;
+
     /*
      * Check if the option can be set at this time. See guc.h for the precise
      * rules.

If we went this way, we'd presumably revert 5a6c39b6d in favor
of marking track_commit_timestamp with this flag.

            regards, tom lane