Fix deadlock hazard in CREATE INDEX CONCURRENTLY Multiple sessions doing CREATE INDEX CONCURRENTLY simultaneously are supposed to be able to work in parallel, as evidenced by fixes in commit c3d09b3bd23f specifically to support this case. In reality, one of the sessions would be aborted by a misterious "deadlock detected" error.
Jeff Janes diagnosed that this is because of leftover snapshots used for system catalog scans -- this was broken by 8aa3e47510b9 keeping track of (registering) the catalog snapshot. To fix the deadlocks, it's enough to de-register that snapshot prior to waiting. Backpatch to 9.4, which introduced MVCC catalog scans. Include an isolationtester spec that 8 out of 10 times reproduces the deadlock with the unpatched code for me (Álvaro). Author: Jeff Janes Diagnosed-by: Jeff Janes Reported-by: Jeremy Finzel Discussion: https://postgr.es/m/CAMa1XUhHjCv8Qkx0WOr1Mpm_R4qxN26EibwCrj0Oor2YBUFUTg%40mail.gmail.com Branch ------ REL9_5_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/82f1c3b7d1e0a7ec6687a5d1c3ee76bb3927cf8f Modified Files -------------- src/backend/commands/indexcmds.c | 3 +++ src/test/isolation/expected/multiple-cic.out | 19 +++++++++++++ src/test/isolation/isolation_schedule | 1 + src/test/isolation/specs/multiple-cic.spec | 40 ++++++++++++++++++++++++++++ 4 files changed, 63 insertions(+)
