Re: POC: Cleaning up orphaned files using undo logs

On Fri, 19 Jul 2019 at 17:24, Amit Khandekar <amitdkhan(dot)pg(at)gmail(dot)com> wrote:
>
> On Thu, 9 May 2019 at 12:04, Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
>
> > Patches can be applied on top of undo branch [1] commit:
> > (cb777466d008e656f03771cf16ec7ef9d6f2778b)
> >
> > [1] https://github.com/EnterpriseDB/zheap/tree/undo
>
> Below are some review points for 0009-undo-page-consistency-checker.patch :

Another point that I missed :

+ * Process the undo record of the page and mask their cid filed.
+ */
+ while (next_record < page_end)
+ {
+ UndoRecordHeader *header = (UndoRecordHeader *) next_record;
+
+ /* If this undo record has cid present, then mask it */
+ if ((header->urec_info & UREC_INFO_CID) != 0)

Here, even though next record starts in the current page, the
urec_info itself may or may not lie on this page.

I hope this possibility is also considered when populating the
partial-record-specific details in the page header.

--
Thanks,
-Amit Khandekar
EnterpriseDB Corporation
The Postgres Database Company