Re: Dump-restore loosing 'attnotnull' bit for DEFERRABLE PRIMARY KEY column(s).

On 2024-Mar-04, Dean Rasheed wrote:

> I don't think that this is the right fix. ISTM that the real issue is
> that dropping a NOT NULL constraint should not mark the column as
> nullable if it is part of a PK, whether or not that PK is deferrable
> -- a deferrable PK still marks a column as not nullable.

Yeah. As I said upthread, a good fix seems to require no longer relying
on RelationGetIndexAttrBitmap to obtain the columns in the primary key,
because that function does not include deferred primary keys. I came up
with the attached POC, which seems to fix the reported problem, but of
course it needs more polish, a working test case, and verifying whether
the new function should be used in more places -- in particular, whether
it can be used to revert the changes to RelationGetIndexList that
b0e96f311985 did.

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