Re: REPACK (CONCURRENTLY) might keep dropped-column data

Hello Radim, thanks for testing!

On 2026-Sep-30, Radim Marek wrote:

> Aha, so on my way to office I started thinking and got more silly ideas,
> and now can confirm this is more widespread than logical subscriber use
> case.

Oh, thanks for the simplified test case. We can fix this easily by
setting the column to null in the tuple to write out, as in the attached
patch. The adjust_toast_pointers() function should perhaps be renamed,
and the comment rewritten, since it's no longer just about toast ...
I didn't do that though.

I put together a crude test case to verify with isolationtester.
Without the fix, this reproduces the bloat you saw; with the fix, the
toast table's size after the repack is zero. This needs some more
boiling before being committable, but it suffices to show the problem.

Regards

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