Re: snapshot too old issues, first around wraparound and then more.
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Thomas Munro <thomas.munro@gmail.com>, Andres Freund <andres@anarazel.de>,
Peter Geoghegan <pg@bowt.ie>,
"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>,
Kevin Grittner <kgrittn@gmail.com>
Date: 2021-06-15T19:49:03Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes: > My general point here is that I would like to know whether we have a > finite number of reasonably localized bugs or a three-ring disaster > that is unrecoverable no matter what we do. Andres seems to think it > is the latter, and I *think* Peter Geoghegan agrees, but I think that > the point might be worth a little more discussion. TBH, I am not clear on that either. > I'm unclear whether > Tom's dislike for the feature represents hostility to the concept - > with which I would have to disagree - or a judgement on the quality of > the implementation - which might be justified. I think it's a klugy, unprincipled solution to a valid real-world problem. I suspect the implementation issues are not unrelated to the kluginess of the concept. Thus, I would really like to see us throw this away and find something better. I admit I have nothing to offer about what a better solution to the problem would look like. But I would really like it to not involve random-seeming query failures. regards, tom lane
Commits
-
Remove the "snapshot too old" feature.
- f691f5b80a85 17.0 landed
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Improve timeout.c's handling of repeated timeout set/cancel.
- 09cf1d522676 14.0 cited
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Fix two bugs in MaintainOldSnapshotTimeMapping.
- 55b7e2f4d78d 14.0 cited