Horton

Re: [HACKERS] [COMMITTERS] pgsql: Fix freezing of a dead HOT-updated tuple

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Peter Geoghegan <pg@bowt.ie>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, "Wood, Dan" <hexpert@amazon.com>, pgsql-committers@postgresql.org, "Wong, Yi Wen" <yiwong@amazon.com>, Michael Paquier <michael.paquier@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2017-12-15T18:58:11Z
Lists: pgsql-hackers 
On 2017-12-15 10:46:05 -0800, Peter Geoghegan wrote:
> On Thu, Dec 14, 2017 at 6:30 PM, Andres Freund <andres@anarazel.de> wrote:
> > Pushed this way.  Moved some more relfrozenxid/relminmxid tests outside
> > of the cutoff changes, polished some error messages.
> >
> >
> > Alvaro, Michael, Peter, and everyone else I'd greatly appreciate if you
> > could have a look at the backported version, just about everything but
> > v10 had conflicts, some of them not insubstantial.
> 
> I have one minor piece of feedback on the upgrading of assertions to
> ereport()s with ERRCODE_DATA_CORRUPTION: It would be nice if you could
> upgrade the raw elog() "can't happen" error within
> IndexBuildHeapRangeScan() to be an ereport() with
> ERRCODE_DATA_CORRUPTION. I'm referring to the "failed to find parent
> tuple for heap-only tuple" error, which I think merits being a real
> user-visible error, just like the relfrozenxid/relminmxid tests are
> now. As you know, the enhanced amcheck will sometimes detect
> corruption due to this bug by hitting that error.

I'm not opposed to that, it just seems independent from this thread. Not
sure I really want to go around and backpatch such a change, that code
has changed a bit between branches. Happy to do so on master.

Greetings,

Andres Freund

Commits

  1. Backport addition of rs_old_rel to rewriteheap's state.

  2. Perform a lot more sanity checks when freezing tuples.

  3. Revert bogus fixes of HOT-freezing bug

  4. Fix traversal of half-frozen update chains

  5. Fix freezing of a dead HOT-updated tuple

  6. During index build, check and elog (not just Assert) for broken HOT chain.

  7. Fix WAL replay of locking an updated tuple

  8. Change the way we mark tuples as frozen.