Re: amcheck (B-Tree integrity checking tool)

On Mon, Feb 29, 2016 at 4:09 PM, Peter Geoghegan <pg(at)heroku(dot)com> wrote:
> To recap, the extension adds some SQL-callable functions that verify
> certain invariant conditions hold within some particular B-Tree index.
> These are the conditions that index scans rely on always being true.
> The tool's scope may eventually cover other AMs, including heapam, but
> nbtree seems like the best place to start.

Noah and I discussed possible future directions for amcheck in person
recently. I would like to get Noah's thoughts again here on how a tool
like amcheck might reasonably target other access methods for
verification. In particular, the heapam. MultiXacts were mentioned as
a structure that could receive verification in a future iteration of
this tool, but I lack expertise there.

I've placed a lot of emphasis on the importance of having a
low-overhead verification process, particularly in terms of the
strength of heavyweight lock that the verification process requires.
Ideally, it would be possible to run any new verification process in a
fairly indiscriminate way with only limited impact on live production
systems.

--
Peter Geoghegan