Add query denormalization regression test for prepared statements

Ensures that the denormalization of prepared statements is working, also
ensure that a query which takes more time to execute replaces the
previous denormalized query.

Makefile

@@ -12,7 +12,7 @@ LDFLAGS_SL += $(filter -lm, $(LIBS))
 
 TAP_TESTS = 1
 REGRESS_OPTS = --temp-config $(top_srcdir)/contrib/pg_stat_monitor/pg_stat_monitor.conf --inputdir=regression
-REGRESS = basic version guc pgsm_query_id functions counters relations database error_insert application_name application_name_unique top_query cmd_type error rows tags user level_tracking
+REGRESS = basic version guc pgsm_query_id functions counters relations database error_insert application_name application_name_unique top_query cmd_type error rows tags user level_tracking denorm_prepared_statements
 
 # Disabled because these tests require "shared_preload_libraries=pg_stat_statements",
 # which typical installcheck users do not have (e.g. buildfarm clients).

regression/expected/denorm_prepared_statements.out

@@ -0,0 +1,35 @@
+CREATE EXTENSION pg_stat_monitor;
+Set pg_stat_monitor.pgsm_normalized_query='off';
+CREATE TABLE t1 (a TEXT, b TEXT, c TEXT);
+SELECT pg_stat_monitor_reset();
+ pg_stat_monitor_reset 
+-----------------------
+
+(1 row)
+
+PREPARE prepstmt(TEXT, TEXT, TEXT) AS INSERT INTO t1(a, b, c) VALUES($1, $2, $3);
+EXECUTE prepstmt('A', 'B', 'C');
+SELECT query, calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
+                                     query                                      | calls 
+--------------------------------------------------------------------------------+-------
+ PREPARE prepstmt(TEXT, TEXT, TEXT) AS INSERT INTO t1(a, b, c) VALUES(A, B, C); |     1
+ SELECT pg_stat_monitor_reset()                                                 |     1
+(2 rows)
+
+EXECUTE prepstmt(REPEAT('XYZ', 8192), md5(random()::text), REPEAT('RANDOM', 4096));
+SELECT SUBSTRING(query, 0, 128), calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
+                                                            substring                                                            | calls 
+---------------------------------------------------------------------------------------------------------------------------------+-------
+ PREPARE prepstmt(TEXT, TEXT, TEXT) AS INSERT INTO t1(a, b, c) VALUES(XYZXYZXYZXYZXYZXYZXYZXYZXYZXYZXYZXYZXYZXYZXYZXYZXYZXYZXYZX |     2
+ SELECT pg_stat_monitor_reset()                                                                                                  |     1
+ SELECT query, calls FROM pg_stat_monitor ORDER BY query COLLATE "C"                                                             |     1
+(3 rows)
+
+DROP TABLE t1;
+SELECT pg_stat_monitor_reset();
+ pg_stat_monitor_reset 
+-----------------------
+
+(1 row)
+
+DROP EXTENSION pg_stat_monitor;

regression/sql/denorm_prepared_statements.sql

@@ -0,0 +1,19 @@
+CREATE EXTENSION pg_stat_monitor;
+Set pg_stat_monitor.pgsm_normalized_query='off';
+
+CREATE TABLE t1 (a TEXT, b TEXT, c TEXT);
+
+SELECT pg_stat_monitor_reset();
+
+PREPARE prepstmt(TEXT, TEXT, TEXT) AS INSERT INTO t1(a, b, c) VALUES($1, $2, $3);
+
+EXECUTE prepstmt('A', 'B', 'C');
+SELECT query, calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
+
+EXECUTE prepstmt(REPEAT('XYZ', 8192), md5(random()::text), REPEAT('RANDOM', 4096));
+SELECT SUBSTRING(query, 0, 128), calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
+
+DROP TABLE t1;
+
+SELECT pg_stat_monitor_reset();
+DROP EXTENSION pg_stat_monitor;