1 files changed, 41 insertions, 0 deletions
diff --git a/src/test/isolation/specs/sequence-ddl.spec b/src/test/isolation/specs/sequence-ddl.spec
new file mode 100644
index 0000000..7ead8af
--- /dev/null
+++ b/src/test/isolation/specs/sequence-ddl.spec
@@ -0,0 +1,41 @@
+# Test sequence usage and concurrent sequence DDL
+
+setup
+{
+    CREATE SEQUENCE seq1;
+}
+
+teardown
+{
+    DROP SEQUENCE seq1;
+}
+
+session s1
+setup           { BEGIN; }
+step s1alter    { ALTER SEQUENCE seq1 MAXVALUE 10; }
+step s1alter2   { ALTER SEQUENCE seq1 MAXVALUE 20; }
+step s1restart  { ALTER SEQUENCE seq1 RESTART WITH 5; }
+step s1commit   { COMMIT; }
+
+session s2
+step s2begin    { BEGIN; }
+step s2nv       { SELECT nextval('seq1') FROM generate_series(1, 15); }
+step s2commit   { COMMIT; }
+
+permutation s1alter s1commit s2nv
+
+# Prior to PG10, the s2nv step would see the uncommitted s1alter
+# change, but now it waits.
+permutation s1alter s2nv s1commit
+
+# Prior to PG10, the s2nv step would see the uncommitted s1restart
+# change, but now it waits.
+permutation s1restart s2nv s1commit
+
+# In contrast to ALTER setval() is non-transactional, so it doesn't
+# have to wait.
+permutation s1restart s2nv s1commit
+
+# nextval doesn't release lock until transaction end, so s1alter2 has
+# to wait for s2commit.
+permutation s2begin s2nv s1alter2 s2commit s1commit