Cleanup and fix some regression tests

Makefile

@@ -31,7 +31,8 @@ REGRESS = basic \
 	user \
 	level_tracking \
 	decode_error_level \
-	parallel
+	parallel \
+	histogram
 
 # Disabled because these tests require "shared_preload_libraries=pg_stat_statements",
 # which typical installcheck users do not have (e.g. buildfarm clients).

regression/expected/histogram.out

@@ -1,16 +1,15 @@
 CREATE OR REPLACE FUNCTION generate_histogram()
     RETURNS TABLE (
-    range TEXT, freq INT, bar TEXT
+    RANGE TEXT, freq INT, bar TEXT
   )  AS $$
-Declare
+DECLARE
     bucket_id integer;
-    query_id text;
+    query_id int8;
 BEGIN
-    select bucket into bucket_id from pg_stat_monitor order by calls desc limit 1;
-    select queryid into query_id from pg_stat_monitor order by calls desc limit 1;
-    --RAISE INFO 'bucket_id %', bucket_id;
-    --RAISE INFO 'query_id %', query_id;
-    return query
+    SELECT bucket, queryid INTO bucket_id, query_id FROM pg_stat_monitor ORDER BY calls DESC LIMIT 1;
+    -- RAISE INFO 'bucket_id %', bucket_id;
+    -- RAISE INFO 'query_id %', query_id;
+    RETURN query
     SELECT * FROM histogram(bucket_id, query_id) AS a(range TEXT, freq INT, bar TEXT);
 END;
 $$ LANGUAGE plpgsql;
@@ -19,53 +18,85 @@ DECLARE
     loops ALIAS FOR $1;
 BEGIN
     FOR i IN 1..loops LOOP
-	--RAISE INFO 'Current timestamp: %', timeofday()::TIMESTAMP;
-	RAISE INFO 'Sleep % seconds', i;
-	PERFORM pg_sleep(i);
+	-- RAISE INFO 'Current timestamp: %', timeofday()::TIMESTAMP;
+    -- 0.4 seconds step used here to hit the same histogram buckets consistently.
+    -- See histogram buckets timing distribution.
+	PERFORM pg_sleep(0.4 * i);
     END LOOP;
 END;
 $$ LANGUAGE 'plpgsql' STRICT;
+CREATE OR REPLACE FUNCTION wait_for_new_bucket() RETURNS VOID AS $$
+DECLARE
+    bucket_left_time int;
+BEGIN
+    -- This test works correctly only if the bucket duration is default (60 seconds).
+    SELECT 60 - EXTRACT(
+        SECOND FROM(
+            SELECT CURRENT_TIMESTAMP(0) bucket_start_time FROM pg_stat_monitor ORDER BY bucket_start_time DESC LIMIT 1
+        )
+    )::int INTO bucket_left_time; 
+
+    -- If the bucket lifetime is less than 10 seconds, we would not fit.
+    IF bucket_left_time <= 4 THEN
+        -- RAISE NOTICE 'Bucket lifetime comes to an end → sleeping 4 seconds...';
+        PERFORM pg_sleep(4);
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
 CREATE EXTENSION pg_stat_monitor;
+SELECT wait_for_new_bucket();
+ wait_for_new_bucket 
+---------------------
+
+(1 row)
+
 SELECT pg_stat_monitor_reset();
  pg_stat_monitor_reset 
 -----------------------
 
 (1 row)
 
-Set pg_stat_monitor.pgsm_track='all';
-select run_pg_sleep(5);
-INFO:  Sleep 1 seconds
-INFO:  Sleep 2 seconds
-INFO:  Sleep 3 seconds
-INFO:  Sleep 4 seconds
-INFO:  Sleep 5 seconds
+SET pg_stat_monitor.pgsm_track='all';
+SELECT run_pg_sleep(5);
  run_pg_sleep 
 --------------
 
 (1 row)
 
-SELECT substr(query, 0,50) as query, calls, resp_calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
-                query                 | calls |      resp_calls       
---------------------------------------+-------+-----------------------
- SELECT pg_sleep(i)                   |     5 | {0,0,0,0,0,0,3,2,0,0}
- SELECT pg_stat_monitor_reset()       |     1 | {1,0,0,0,0,0,0,0,0,0}
- Set pg_stat_monitor.pgsm_track='all' |     1 | {1,0,0,0,0,0,0,0,0,0}
- select run_pg_sleep(5)               |     1 | {0,0,0,0,0,0,0,0,1,0}
+SELECT substr(query, 0, 50) as query, calls, resp_calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
+                query                 | calls |                  resp_calls                   
+--------------------------------------+-------+-----------------------------------------------
+ SELECT pg_sleep(0.4 * i)             |     5 | {0,0,0,0,0,0,0,0,0,0,0,1,1,2,1,0,0,0,0,0,0,0}
+ SELECT pg_stat_monitor_reset()       |     1 | {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
+ SELECT run_pg_sleep(5)               |     1 | {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0}
+ SET pg_stat_monitor.pgsm_track='all' |     1 | {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
 (4 rows)
 
-select * from generate_histogram();
-       range        | freq |              bar               
---------------------+------+--------------------------------
- (0 - 3)}           |    0 | 
-  (3 - 10)}         |    0 | 
-  (10 - 31)}        |    0 | 
-  (31 - 100)}       |    0 | 
-  (100 - 316)}      |    0 | 
-  (316 - 1000)}     |    0 | 
-  (1000 - 3162)}    |    3 | ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
-  (3162 - 10000)}   |    2 | ■■■■■■■■■■■■■■■■■■■■
-  (10000 - 31622)}  |    0 | 
-  (31622 - 100000)} |    0 | 
-(10 rows)
+SELECT * FROM generate_histogram();
+           range           | freq |              bar               
+---------------------------+------+--------------------------------
+ {{0.000 - 1.000}          |    0 | 
+  (1.000 - 2.778}          |    0 | 
+  (2.778 - 4.162}          |    0 | 
+  (4.162 - 6.623}          |    0 | 
+  (6.623 - 11.000}         |    0 | 
+  (11.000 - 18.783}        |    0 | 
+  (18.783 - 32.623}        |    0 | 
+  (32.623 - 57.234}        |    0 | 
+  (57.234 - 101.000}       |    0 | 
+  (101.000 - 178.827}      |    0 | 
+  (178.827 - 317.226}      |    0 | 
+  (317.226 - 563.338}      |    1 | ■■■■■■■■■■■■■■■
+  (563.338 - 1000.994}     |    1 | ■■■■■■■■■■■■■■■
+  (1000.994 - 1779.268}    |    2 | ■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
+  (1779.268 - 3163.256}    |    1 | ■■■■■■■■■■■■■■■
+  (3163.256 - 5624.371}    |    0 | 
+  (5624.371 - 10000.920}   |    0 | 
+  (10000.920 - 17783.643}  |    0 | 
+  (17783.643 - 31623.492}  |    0 | 
+  (31623.492 - 56234.598}  |    0 | 
+  (56234.598 - 100000.000} |    0 | 
+  (100000.000 - ...}}      |    0 | 
+(22 rows)
 
 DROP EXTENSION pg_stat_monitor;

regression/expected/parallel_1.out

@@ -37,3 +37,4 @@ SELECT query,
 (1 row)
 
 DROP TABLE pgsm_parallel_tab;
+DROP EXTENSION pg_stat_monitor;

regression/sql/histogram.sql

@@ -1,16 +1,15 @@
 CREATE OR REPLACE FUNCTION generate_histogram()
     RETURNS TABLE (
-    range TEXT, freq INT, bar TEXT
+    RANGE TEXT, freq INT, bar TEXT
   )  AS $$
-Declare
+DECLARE
     bucket_id integer;
-    query_id text;
+    query_id int8;
 BEGIN
-    select bucket into bucket_id from pg_stat_monitor order by calls desc limit 1;
-    select queryid into query_id from pg_stat_monitor order by calls desc limit 1;
-    --RAISE INFO 'bucket_id %', bucket_id;
-    --RAISE INFO 'query_id %', query_id;
-    return query
+    SELECT bucket, queryid INTO bucket_id, query_id FROM pg_stat_monitor ORDER BY calls DESC LIMIT 1;
+    -- RAISE INFO 'bucket_id %', bucket_id;
+    -- RAISE INFO 'query_id %', query_id;
+    RETURN query
     SELECT * FROM histogram(bucket_id, query_id) AS a(range TEXT, freq INT, bar TEXT);
 END;
 $$ LANGUAGE plpgsql;
@@ -20,20 +19,41 @@ DECLARE
     loops ALIAS FOR $1;
 BEGIN
     FOR i IN 1..loops LOOP
-	--RAISE INFO 'Current timestamp: %', timeofday()::TIMESTAMP;
-	RAISE INFO 'Sleep % seconds', i;
-	PERFORM pg_sleep(i);
+	-- RAISE INFO 'Current timestamp: %', timeofday()::TIMESTAMP;
+    -- 0.4 seconds step used here to hit the same histogram buckets consistently.
+    -- See histogram buckets timing distribution.
+	PERFORM pg_sleep(0.4 * i);
     END LOOP;
 END;
 $$ LANGUAGE 'plpgsql' STRICT;
 
+CREATE OR REPLACE FUNCTION wait_for_new_bucket() RETURNS VOID AS $$
+DECLARE
+    bucket_left_time int;
+BEGIN
+    -- This test works correctly only if the bucket duration is default (60 seconds).
+    SELECT 60 - EXTRACT(
+        SECOND FROM(
+            SELECT CURRENT_TIMESTAMP(0) bucket_start_time FROM pg_stat_monitor ORDER BY bucket_start_time DESC LIMIT 1
+        )
+    )::int INTO bucket_left_time; 
+
+    -- If the bucket lifetime is less than 10 seconds, we would not fit.
+    IF bucket_left_time <= 4 THEN
+        -- RAISE NOTICE 'Bucket lifetime comes to an end → sleeping 4 seconds...';
+        PERFORM pg_sleep(4);
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
 CREATE EXTENSION pg_stat_monitor;
+SELECT wait_for_new_bucket();
 SELECT pg_stat_monitor_reset();
-Set pg_stat_monitor.pgsm_track='all';
-select run_pg_sleep(5);
+SET pg_stat_monitor.pgsm_track='all';
+SELECT run_pg_sleep(5);
 
-SELECT substr(query, 0,50) as query, calls, resp_calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
+SELECT substr(query, 0, 50) as query, calls, resp_calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
 
-select * from generate_histogram();
+SELECT * FROM generate_histogram();
 
 DROP EXTENSION pg_stat_monitor;

regression/sql/parallel.sql

@@ -30,3 +30,4 @@ SELECT query,
   ORDER BY query COLLATE "C";
 
 DROP TABLE pgsm_parallel_tab;
+DROP EXTENSION pg_stat_monitor;