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# Test for interactions of tuple freezing with dead, as well as recently-dead
# tuples using multixacts via FOR KEY SHARE.
setup
{
CREATE TABLE tab_freeze (
id int PRIMARY KEY,
name char(3),
x int);
INSERT INTO tab_freeze VALUES (1, '111', 0);
INSERT INTO tab_freeze VALUES (3, '333', 0);
}
teardown
{
DROP TABLE tab_freeze;
}
session "s1"
step "s1_begin" { BEGIN; }
step "s1_update" { UPDATE tab_freeze SET x = x + 1 WHERE id = 3; }
step "s1_commit" { COMMIT; }
step "s1_selectone" {
BEGIN;
SET LOCAL enable_seqscan = false;
SET LOCAL enable_bitmapscan = false;
SELECT * FROM tab_freeze WHERE id = 3;
COMMIT;
}
step "s1_selectall" { SELECT * FROM tab_freeze ORDER BY name, id; }
session "s2"
step "s2_begin" { BEGIN; }
step "s2_key_share" { SELECT id FROM tab_freeze WHERE id = 3 FOR KEY SHARE; }
step "s2_commit" { COMMIT; }
step "s2_vacuum" { VACUUM FREEZE tab_freeze; }
session "s3"
step "s3_begin" { BEGIN; }
step "s3_key_share" { SELECT id FROM tab_freeze WHERE id = 3 FOR KEY SHARE; }
step "s3_commit" { COMMIT; }
# This permutation verifies that a previous bug
# https://postgr.es/m/E5711E62-8FDF-4DCA-A888-C200BF6B5742@amazon.com
# https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
# is not reintroduced. We used to make wrong pruning / freezing
# decision for multixacts, which could lead to a) broken hot chains b)
# dead rows being revived.
permutation "s1_begin" "s2_begin" "s3_begin" # start transactions
"s1_update" "s2_key_share" "s3_key_share" # have xmax be a multi with an updater, updater being oldest xid
"s1_update" # create additional row version that has multis
"s1_commit" "s2_commit" # commit both updater and share locker
"s2_vacuum" # due to bug in freezing logic, we used to *not* prune updated row, and then froze it
"s1_selectone" # if hot chain is broken, the row can't be found via index scan
"s3_commit" # commit remaining open xact
"s2_vacuum" # pruning / freezing in broken hot chains would unset xmax, reviving rows
"s1_selectall" # show borkedness
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