1 files changed, 48 insertions, 0 deletions
diff --git a/src/test/isolation/specs/vacuum-reltuples.spec b/src/test/isolation/specs/vacuum-reltuples.spec
new file mode 100644
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+++ b/src/test/isolation/specs/vacuum-reltuples.spec
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+# Test for vacuum's handling of reltuples when pages are skipped due
+# to page pins. We absolutely need to avoid setting reltuples=0 in
+# such cases, since that interferes badly with planning.
+#
+# Expected result in second permutation is 20 tuples rather than 21 as
+# for the others, because vacuum should leave the previous result
+# (from before the insert) in place.
+
+setup {
+    create table smalltbl
+        as select i as id from generate_series(1,20) i;
+    alter table smalltbl set (autovacuum_enabled = off);
+}
+setup {
+    vacuum analyze smalltbl;
+}
+
+teardown {
+    drop table smalltbl;
+}
+
+session worker
+step open {
+    begin;
+    declare c1 cursor for select 1 as dummy from smalltbl;
+}
+step fetch1 {
+    fetch next from c1;
+}
+step close {
+    commit;
+}
+step stats {
+    select relpages, reltuples from pg_class
+     where oid='smalltbl'::regclass;
+}
+
+session vacuumer
+step vac {
+    vacuum smalltbl;
+}
+step modify {
+    insert into smalltbl select max(id)+1 from smalltbl;
+}
+
+permutation modify vac stats
+permutation modify open fetch1 vac close stats
+permutation modify vac stats