Re: [HACKERS] WIP: long transactions on hot standby feedback replica / proof of concept

2017-09-15 Thread i . kartyshov
Alexander Korotkov писал 2017-09-05 00:33: I've following comments on this patch: 1) You shouldn't use ">=" to compare xids. You should use TransactionIdFollowsOrEquals() function which handles transaction id wraparound correctly. I fixed it and as an additional I add GUC parameter that could

Re: [HACKERS] make async slave to wait for lsn to be replayed

2017-09-04 Thread i . kartyshov
I forget to include patch in last letter. Craig Ringer wrote 2017-08-15 05:00: That ship sailed a long time ago unfortunately, they're all over pg_stat_replication and pg_replication_slots and so on. They're already routinely used for monitoring replication lag in bytes, waiting for a peer to

Re: [HACKERS] make async slave to wait for lsn to be replayed

2017-09-04 Thread i . kartyshov
Hello, thank you for your comments over main idea and code. On 13.03.2017 05:20, Thomas Munro wrote: 1) First, I'll restate my view of the syntax-vs-function question: I think an fmgr function is the wrong place to do this, because it doesn't work for our 2 higher isolation levels as

[HACKERS] WIP: long transactions on hot standby feedback replica / proof of concept

2017-09-04 Thread i . kartyshov
Our clients complain about this issue and therefore I want to raise the discussion and suggest several solutions to this problem: I. Why does PG use Fatal when Error is enough to release lock that rises lock conflict? "If (RecoveryConflictPending && DoingCommandRead)" II. Do we really need