Injection points for hash aggregation.

Requires adding a guard against shift-by-32. Previously, that was
impossible because the number of partitions was always greater than 1,
but a new injection point can force the number of partitions to 1.

Discussion: https://postgr.es/m/ff4e59305e5d689e03cd256a736348d3e7958f8f.camel@j-davis.com

1 files changed, 26 insertions, 0 deletions

diff --git a/src/test/modules/injection_points/sql/hashagg.sql b/src/test/modules/injection_points/sql/hashagg.sql
new file mode 100644
index 00000000000..51d814623fc
--- /dev/null
+++ b/src/test/modules/injection_points/sql/hashagg.sql
@@ -0,0 +1,26 @@
+-- Test for hash aggregation
+CREATE EXTENSION injection_points;
+
+SELECT injection_points_set_local();
+
+SELECT injection_points_attach('hash-aggregate-enter-spill-mode', 'notice');
+SELECT injection_points_attach('hash-aggregate-process-batch', 'notice');
+
+-- force partition fan-out to 1
+SELECT injection_points_attach('hash-aggregate-single-partition', 'notice');
+
+-- force spilling after 1000 groups
+SELECT injection_points_attach('hash-aggregate-spill-1000', 'notice');
+
+CREATE TABLE hashagg_ij(x INTEGER);
+INSERT INTO hashagg_ij SELECT g FROM generate_series(1,5100) g;
+
+SET max_parallel_workers=0;
+SET max_parallel_workers_per_gather=0;
+SET enable_sort=FALSE;
+SET work_mem='4MB';
+
+SELECT COUNT(*) FROM (SELECT DISTINCT x FROM hashagg_ij) s;
+
+DROP TABLE hashagg_ij;
+DROP EXTENSION injection_points;