Add some pg session function to pg_catalog

src/catalog/default/default_functions.cpp

@@ -27,6 +27,11 @@ static DefaultMacro internal_macros[] = {
 
 	{"pg_catalog", "pg_typeof", {"expression", nullptr}, "lower(typeof(expression))"},  // get the data type of any value
 
+	{"pg_catalog", "current_database", {nullptr}, "current_database()"},  	    // name of current database (called "catalog" in the SQL standard)
+	{"pg_catalog", "current_query", {nullptr}, "current_query()"},  	        // the currently executing query (NULL if not inside a plpgsql function)
+	{"pg_catalog", "current_schema", {nullptr}, "current_schema()"},  	        // name of current schema
+	{"pg_catalog", "current_schemas", {"include_implicit"}, "current_schemas(include_implicit)"},  	// names of schemas in search path
+
 	// privilege functions
 	// {"has_any_column_privilege", {"user", "table", "privilege", nullptr}, "true"},  //boolean  //does user have privilege for any column of table
 	{"pg_catalog", "has_any_column_privilege", {"table", "privilege", nullptr}, "true"},  //boolean  //does current user have privilege for any column of table

test/sql/catalog/test_set_search_path.test

@@ -90,6 +90,11 @@ SELECT MAIN.CURRENT_SCHEMAS(false);
 ----
 [test, test2]
 
+query I
+SELECT pg_catalog.CURRENT_SCHEMAS(false);
+----
+[test, test2]
+
 statement ok
 SET SCHEMA = 'test';
 
@@ -103,6 +108,11 @@ SELECT MAIN.CURRENT_SCHEMA();
 ----
 test
 
+query I
+SELECT pg_catalog.CURRENT_SCHEMA();
+----
+test
+
 query I
 SELECT current_schema();
 ----

test/sql/pg_catalog/system_functions.test

@@ -20,6 +20,11 @@ SELECT CURRENT_DATABASE()
 ----
 memory
 
+query I
+SELECT pg_catalog.CURRENT_DATABASE()
+----
+memory
+
 query I
 SELECT USER
 ----
@@ -38,6 +43,11 @@ SELECT current_query();
 ----
 SELECT current_query();
 
+query I
+SELECT pg_catalog.current_query();
+----
+SELECT pg_catalog.current_query();
+
 query IIII
 SELECT 1, 2, 3, current_query();
 ----