Remove the query_id_squash_values GUC

Commit 62d712ecfd94 introduced the capability to calculate the same
queryId for queries with different lengths of constants in a list for an
IN clause.  This behavior was originally enabled with a GUC
query_id_squash_values.  After a discussion about the value of such a
GUC, it was decided to back out of the use of a GUC and make the
squashing behavior the only available option.

Author: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/Z-LZyygkkNyA8-kR@msg.df7cb.de
Discussion: https://postgr.es/m/CA+q6zcVTK-3C-8NWV1oY2NZrvtnMCDqnyYYyk1T7WMUG65MeOQ@mail.gmail.com

3 files changed, 1 insertions, 44 deletions

diff --git a/contrib/pg_stat_statements/expected/dml.out b/contrib/pg_stat_statements/expected/dml.out
index acc2c5e5241..347cb8699e4 100644
--- a/contrib/pg_stat_statements/expected/dml.out
+++ b/contrib/pg_stat_statements/expected/dml.out
@@ -80,7 +80,7 @@ SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C";
      1 |   10 | INSERT INTO pgss_dml_tab VALUES(generate_series($1, $2), $3)
      1 |   12 | SELECT * FROM pgss_dml_tab ORDER BY a
      2 |    4 | SELECT * FROM pgss_dml_tab WHERE a > $1 ORDER BY a
-     1 |    8 | SELECT * FROM pgss_dml_tab WHERE a IN ($1, $2, $3, $4, $5)
+     1 |    8 | SELECT * FROM pgss_dml_tab WHERE a IN ($1 /*, ... */)
      1 |    1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
      1 |    0 | SET pg_stat_statements.track_utility = $1
      6 |    6 | UPDATE pgss_dml_tab SET b = $1 WHERE a = $2
diff --git a/contrib/pg_stat_statements/expected/squashing.out b/contrib/pg_stat_statements/expected/squashing.out
index 55aa5109433..7b138af098c 100644
--- a/contrib/pg_stat_statements/expected/squashing.out
+++ b/contrib/pg_stat_statements/expected/squashing.out
@@ -4,39 +4,7 @@
 CREATE EXTENSION pg_stat_statements;
 CREATE TABLE test_squash (id int, data int);
 -- IN queries
--- No squashing is performed, as a baseline result
-SELECT pg_stat_statements_reset() IS NOT NULL AS t;
- t 
----
- t
-(1 row)
-
-SELECT * FROM test_squash WHERE id IN (1, 2, 3, 4, 5, 6, 7, 8, 9);
- id | data 
-----+------
-(0 rows)
-
-SELECT * FROM test_squash WHERE id IN (1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
- id | data 
-----+------
-(0 rows)
-
-SELECT * FROM test_squash WHERE id IN (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11);
- id | data 
-----+------
-(0 rows)
-
-SELECT query, calls FROM pg_stat_statements ORDER BY query COLLATE "C";
-                                        query                                         | calls 
---------------------------------------------------------------------------------------+-------
- SELECT * FROM test_squash WHERE id IN ($1, $2, $3, $4, $5, $6, $7, $8, $9)           |     1
- SELECT * FROM test_squash WHERE id IN ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)      |     1
- SELECT * FROM test_squash WHERE id IN ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11) |     1
- SELECT pg_stat_statements_reset() IS NOT NULL AS t                                   |     1
-(4 rows)
-
 -- Normal scenario, too many simple constants for an IN query
-SET query_id_squash_values = on;
 SELECT pg_stat_statements_reset() IS NOT NULL AS t;
  t 
 ---
@@ -461,4 +429,3 @@ SELECT query, calls FROM pg_stat_statements ORDER BY query COLLATE "C";
  SELECT pg_stat_statements_reset() IS NOT NULL AS t |     1
 (2 rows)
 
-RESET query_id_squash_values;
diff --git a/contrib/pg_stat_statements/sql/squashing.sql b/contrib/pg_stat_statements/sql/squashing.sql
index 56ee8ccb9a1..908be81ff2b 100644
--- a/contrib/pg_stat_statements/sql/squashing.sql
+++ b/contrib/pg_stat_statements/sql/squashing.sql
@@ -7,16 +7,7 @@ CREATE TABLE test_squash (id int, data int);
 
 -- IN queries
 
--- No squashing is performed, as a baseline result
-SELECT pg_stat_statements_reset() IS NOT NULL AS t;
-SELECT * FROM test_squash WHERE id IN (1, 2, 3, 4, 5, 6, 7, 8, 9);
-SELECT * FROM test_squash WHERE id IN (1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
-SELECT * FROM test_squash WHERE id IN (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11);
-SELECT query, calls FROM pg_stat_statements ORDER BY query COLLATE "C";
-
 -- Normal scenario, too many simple constants for an IN query
-SET query_id_squash_values = on;
-
 SELECT pg_stat_statements_reset() IS NOT NULL AS t;
 SELECT * FROM test_squash WHERE id IN (1);
 SELECT * FROM test_squash WHERE id IN (1, 2, 3);
@@ -177,4 +168,3 @@ SELECT pg_stat_statements_reset() IS NOT NULL AS t;
 SELECT ARRAY[1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
 SELECT query, calls FROM pg_stat_statements ORDER BY query COLLATE "C";
 
-RESET query_id_squash_values;