On Fri, Dec 8, 2023 at 11:46 AM Kartyshov Ivan <i.kartys...@postgrespro.ru> wrote: > > Should rise disscusion on separate utility statement or find > case where procedure version is failed. > > 1) Classic (wait_classic_v3.patch) > https://www.postgresql.org/message-id/3cc883048264c2e9af022033925ff8db%40postgrespro.ru > ========== > advantages: multiple wait events, separate WAIT FOR statement > disadvantages: new words in grammar > > > > WAIT FOR [ANY | ALL] event [, ...] > BEGIN [ WORK | TRANSACTION ] [ transaction_mode [, ...] ] > [ WAIT FOR [ANY | ALL] event [, ...]] > event: > LSN value > TIMEOUT number_of_milliseconds > timestamp
Nice, but as you stated requires new keywords. > 2) After style: Kyotaro and Freund (wait_after_within_v2.patch) > https://www.postgresql.org/message-id/d3ff2e363af60b345f82396992595a03%40postgrespro.ru > ========== > advantages: no new words in grammar > disadvantages: a little harder to understand > > > > AFTER lsn_event [ WITHIN delay_milliseconds ] [, ...] > BEGIN [ WORK | TRANSACTION ] [ transaction_mode [, ...] ] > [ AFTER lsn_event [ WITHIN delay_milliseconds ]] > START [ WORK | TRANSACTION ] [ transaction_mode [, ...] ] > [ AFTER lsn_event [ WITHIN delay_milliseconds ]] +1 from me > 3) Procedure style: Tom Lane and Kyotaro (wait_proc_v7.patch) > https://www.postgresql.org/message-id/27171.1586439221%40sss.pgh.pa.us > https://www.postgresql.org/message-id/20210121.173009.235021120161403875.horikyota.ntt%40gmail.com > ========== > advantages: no new words in grammar,like it made in > pg_last_wal_replay_lsn > disadvantages: use snapshot xmin trick > SELECT pg_waitlsn(‘LSN’, timeout); > SELECT pg_waitlsn_infinite(‘LSN’); > SELECT pg_waitlsn_no_wait(‘LSN’); Nice, because simplicity. But only safe if called within the simple query containing nothing else. Validating this from the function kills the simplicity. ------ Regards, Alexander Korotkov
