On Fri, Oct 1, 2021 at 5:05 AM Peter Eisentraut <peter.eisentr...@enterprisedb.com> wrote: > > On 30.09.21 07:45, Masahiko Sawada wrote: > > I've attached updated patches that incorporate all comments I got so > > far. Please review them. > > I'm uneasy about the way the xids-to-be-skipped are presented as > subscriptions options, similar to settings such as "binary". I see how > that is convenient, but it's not really the same thing, in how you use > it, is it? Even if we share some details internally, I feel that there > should be a separate syntax somehow.
Since I was thinking that ALTER SUBSCRIPTION ... SET is used to alter parameters originally set by CREATE SUBSCRIPTION, in the first several version patches it added a separate syntax for this feature like ALTER SUBSCRIPTION ... SET SKIP TRANSACTION xxx. But Amit was concerned about an additional syntax and consistency with disable_on_error[1] which is proposed by Mark Diliger[2], so I’ve changed it to a subscription option. I tried to find a policy of that by checking the existing syntaxes but I could not find, and interestingly when it comes to ALTER SUBSCRIPTION syntax, we support both ENABLE/DISABLE syntax and SET (enabled = on/off) option. > Also, what happens when you forget to reset the xid after it has passed? > Will it get skipped again after wraparound? Yes. Currently it's a user's responsibility. We thoroughly documented the risk of this feature and thus it should be used as a last resort since it may easily make the subscriber inconsistent, especially if a user specifies the wrong transaction ID. Regards, [1] https://www.postgresql.org/message-id/CAA4eK1LjrU8x%2Bx%3DbFazVD10pgOVy0PEE8mpz3nQhDG%2BmmU8ivQ%40mail.gmail.com [2] https://www.postgresql.org/message-id/DB35438F-9356-4841-89A0-412709EBD3AB%40enterprisedb.com -- Masahiko Sawada EDB: https://www.enterprisedb.com/
