PG16 - Add rules option to CREATE COLLATION (#7185)

Relevant PG commit:
https://github.com/postgres/postgres/commit/30a53b7
30a53b7

src/backend/distributed/commands/collation.c

@@ -188,7 +188,16 @@ CreateCollationDDLInternal(Oid collationId, Oid *collowner, char **quotedCollati
 	pfree(collcollate);
 	pfree(collctype);
 #endif
-
+#if PG_VERSION_NUM >= PG_VERSION_16
+	char *collicurules = NULL;
+	datum = SysCacheGetAttr(COLLOID, heapTuple, Anum_pg_collation_collicurules, &isnull);
+	if (!isnull)
+	{
+		collicurules = TextDatumGetCString(datum);
+		appendStringInfo(&collationNameDef, ", rules = %s",
+						 quote_literal_cstr(collicurules));
+	}
+#endif
 	if (!collisdeterministic)
 	{
 		appendStringInfoString(&collationNameDef, ", deterministic = false");

src/test/regress/expected/pg16.out

@@ -313,6 +313,90 @@ SELECT result FROM run_command_on_workers
  DROP DATABASE
 (2 rows)
 
+SET search_path TO pg16;
+-- New rules option added to CREATE COLLATION
+-- Similar to above test with CREATE DATABASE
+-- Relevant PG commit:
+-- https://github.com/postgres/postgres/commit/30a53b7
+CREATE COLLATION default_rule (provider = icu, locale = '');
+NOTICE:  using standard form "und" for ICU locale ""
+CREATE COLLATION special_rule (provider = icu, locale = '', rules = '&a < g');
+NOTICE:  using standard form "und" for ICU locale ""
+CREATE TABLE test_collation_rules (a text);
+SELECT create_distributed_table('test_collation_rules', 'a');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+INSERT INTO test_collation_rules VALUES ('Abernathy'), ('apple'), ('bird'), ('Boston'), ('Graham'), ('green');
+SELECT collname, collprovider, colliculocale, collicurules
+FROM pg_collation
+WHERE collname like '%_rule%'
+ORDER BY 1;
+   collname   | collprovider | colliculocale | collicurules
+---------------------------------------------------------------------
+ default_rule | i            | und           |
+ special_rule | i            | und           | &a < g
+(2 rows)
+
+SELECT * FROM test_collation_rules ORDER BY a COLLATE default_rule;
+     a
+---------------------------------------------------------------------
+ Abernathy
+ apple
+ bird
+ Boston
+ Graham
+ green
+(6 rows)
+
+SELECT * FROM test_collation_rules ORDER BY a COLLATE special_rule;
+     a
+---------------------------------------------------------------------
+ Abernathy
+ apple
+ green
+ bird
+ Boston
+ Graham
+(6 rows)
+
+\c - - - :worker_1_port
+SET search_path TO pg16;
+SELECT collname, collprovider, colliculocale, collicurules
+FROM pg_collation
+WHERE collname like '%_rule%'
+ORDER BY 1;
+   collname   | collprovider | colliculocale | collicurules
+---------------------------------------------------------------------
+ default_rule | i            | und           |
+ special_rule | i            | und           | &a < g
+(2 rows)
+
+SELECT * FROM test_collation_rules ORDER BY a COLLATE default_rule;
+     a
+---------------------------------------------------------------------
+ Abernathy
+ apple
+ bird
+ Boston
+ Graham
+ green
+(6 rows)
+
+SELECT * FROM test_collation_rules ORDER BY a COLLATE special_rule;
+     a
+---------------------------------------------------------------------
+ Abernathy
+ apple
+ green
+ bird
+ Boston
+ Graham
+(6 rows)
+
+\c - - - :master_port
 SET search_path TO pg16;
 SET citus.next_shard_id TO 951000;
 -- Foreign table TRUNCATE trigger

src/test/regress/sql/pg16.sql

@@ -146,6 +146,40 @@ DROP DATABASE test_db;
 SELECT result FROM run_command_on_workers
 ($$DROP DATABASE test_db$$);
 SET search_path TO pg16;
+
+-- New rules option added to CREATE COLLATION
+-- Similar to above test with CREATE DATABASE
+-- Relevant PG commit:
+-- https://github.com/postgres/postgres/commit/30a53b7
+
+CREATE COLLATION default_rule (provider = icu, locale = '');
+CREATE COLLATION special_rule (provider = icu, locale = '', rules = '&a < g');
+
+CREATE TABLE test_collation_rules (a text);
+SELECT create_distributed_table('test_collation_rules', 'a');
+INSERT INTO test_collation_rules VALUES ('Abernathy'), ('apple'), ('bird'), ('Boston'), ('Graham'), ('green');
+
+SELECT collname, collprovider, colliculocale, collicurules
+FROM pg_collation
+WHERE collname like '%_rule%'
+ORDER BY 1;
+
+SELECT * FROM test_collation_rules ORDER BY a COLLATE default_rule;
+SELECT * FROM test_collation_rules ORDER BY a COLLATE special_rule;
+
+\c - - - :worker_1_port
+SET search_path TO pg16;
+
+SELECT collname, collprovider, colliculocale, collicurules
+FROM pg_collation
+WHERE collname like '%_rule%'
+ORDER BY 1;
+
+SELECT * FROM test_collation_rules ORDER BY a COLLATE default_rule;
+SELECT * FROM test_collation_rules ORDER BY a COLLATE special_rule;
+
+\c - - - :master_port
+SET search_path TO pg16;
 SET citus.next_shard_id TO 951000;
 
 -- Foreign table TRUNCATE trigger