Re: incremental backup mishandles XLOG_DBASE_CREATE_FILE_COPY

On Sat, Feb 24, 2024 at 10:05 AM Noah Misch <noah(at)leadboat(dot)com> wrote:
> Regarding records the summarizer potentially can't ignore that don't deal in
> relfilenodes, these come to mind:
>
> XLOG_DBASE_DROP - covered in this thread's patch
> XLOG_RELMAP_UPDATE
> XLOG_TBLSPC_CREATE
> XLOG_TBLSPC_DROP
> XLOG_XACT_PREPARE

At present, only relation data files are ever sent incrementally; I
don't think any of these touch those.

> Also, any record that writes XIDs needs to update nextXid; likewise for other
> ID spaces. See the comment at "XLOG stuff" in heap_lock_tuple(). Perhaps you
> don't summarize past a checkpoint, making that irrelevant.

I'm not quite following this. It's true that we summarize from one
redo pointer to the next; but also, our summary is only trying to
ascertain which relation data blocks have been modified. Therefore, I
don't understand the relevance of nextXid here.

--
Robert Haas
EDB: http://www.enterprisedb.com