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Diffstat (limited to '')
| -rw-r--r-- | src/test/isolation/specs/freeze-the-dead.spec | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/src/test/isolation/specs/freeze-the-dead.spec b/src/test/isolation/specs/freeze-the-dead.spec new file mode 100644 index 0000000..6c34904 --- /dev/null +++ b/src/test/isolation/specs/freeze-the-dead.spec @@ -0,0 +1,56 @@ +# 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 |