diff --git a/regression/expected/denorm_prepared_statements.out b/regression/expected/denorm_prepared_statements.out
index a4f1846..c0b3811 100644
--- a/regression/expected/denorm_prepared_statements.out
+++ b/regression/expected/denorm_prepared_statements.out
@@ -7,6 +7,8 @@ SELECT pg_stat_monitor_reset();
  
 (1 row)
 
+-- First test, execute cheap query then heavy query.
+-- Ensure denormalized heavy query replaces the cheaper one.
 PREPARE prepstmt(TEXT, TEXT, TEXT) AS INSERT INTO t1(a, b, c) VALUES($1, $2, $3);
 EXECUTE prepstmt('A', 'B', 'C');
 SELECT SUBSTRING(query, 0, 128), calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
@@ -25,6 +27,32 @@ SELECT SUBSTRING(query, 0, 128), calls FROM pg_stat_monitor ORDER BY query COLLA
  SELECT pg_stat_monitor_reset()                                                                                                  |     1
 (3 rows)
 
+TRUNCATE TABLE t1;
+SELECT pg_stat_monitor_reset();
+ pg_stat_monitor_reset 
+-----------------------
+ 
+(1 row)
+
+-- Second test, execute heavy query then cheap query.
+-- Ensure denormalized heavy query is not replaced by the cheaper one.
+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 |     1
+ SELECT pg_stat_monitor_reset()                                                                                                  |     1
+(2 rows)
+
+EXECUTE prepstmt('A', 'B', 'C');
+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 SUBSTRING(query, 0, 128), calls FROM pg_stat_monitor ORDER BY query COLLATE "C"                                          |     1
+ SELECT pg_stat_monitor_reset()                                                                                                  |     1
+(3 rows)
+
 DROP TABLE t1;
 SELECT pg_stat_monitor_reset();
  pg_stat_monitor_reset 
diff --git a/regression/sql/denorm_prepared_statements.sql b/regression/sql/denorm_prepared_statements.sql
index 94c6935..440f9a2 100644
--- a/regression/sql/denorm_prepared_statements.sql
+++ b/regression/sql/denorm_prepared_statements.sql
@@ -5,6 +5,8 @@ CREATE TABLE t1 (a TEXT, b TEXT, c TEXT);
 
 SELECT pg_stat_monitor_reset();
 
+-- First test, execute cheap query then heavy query.
+-- Ensure denormalized heavy query replaces the cheaper one.
 PREPARE prepstmt(TEXT, TEXT, TEXT) AS INSERT INTO t1(a, b, c) VALUES($1, $2, $3);
 
 EXECUTE prepstmt('A', 'B', 'C');
@@ -13,6 +15,18 @@ SELECT SUBSTRING(query, 0, 128), calls FROM pg_stat_monitor ORDER BY query COLLA
 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";
 
+TRUNCATE TABLE t1;
+SELECT pg_stat_monitor_reset();
+
+-- Second test, execute heavy query then cheap query.
+-- Ensure denormalized heavy query is not replaced by the cheaper one.
+
+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";
+
+EXECUTE prepstmt('A', 'B', 'C');
+SELECT SUBSTRING(query, 0, 128), calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
+
 DROP TABLE t1;
 
 SELECT pg_stat_monitor_reset();