support SHOW CHANGED SETTINGS query and add test cases, also do code changes to compile SHOW SETTINGS PROFILES.

src/Interpreters/InterpreterShowTablesQuery.cpp

@@ -85,10 +85,13 @@ String InterpreterShowTablesQuery::getRewrittenQuery()
         WriteBufferFromOwnString rewritten_query;
         rewritten_query << "SELECT name, type, value FROM system.settings";
 
+        if (query.changed)
+            rewritten_query << " WHERE changed = 1";
+
         if (!query.like.empty())
         {
             rewritten_query
-                << " WHERE name "
+                << (query.changed ? " AND name " : " WHERE name ")
                 << (query.case_insensitive_like ? "ILIKE " : "LIKE ")
                 << DB::quote << query.like;
         }

src/Parsers/ASTShowTablesQuery.cpp

@@ -57,7 +57,8 @@ void ASTShowTablesQuery::formatQueryImpl(const FormatSettings & settings, Format
     }
     else if (m_settings)
     {
-        settings.ostr << (settings.hilite ? hilite_keyword : "") << "SHOW SETTINGS" << (settings.hilite ? hilite_none : "");
+        settings.ostr << (settings.hilite ? hilite_keyword : "") << "SHOW " << (changed ? "CHANGED " : "") << "SETTINGS" <<
+            (settings.hilite ? hilite_none : "");
         formatLike(settings);
     }
     else

src/Parsers/ASTShowTablesQuery.h

@@ -19,6 +19,7 @@ public:
     bool cluster{false};
     bool dictionaries{false};
     bool m_settings{false};
+    bool changed{false};
     bool temporary{false};
 
     String cluster_str;

src/Parsers/ParserShowTablesQuery.cpp

@@ -25,6 +25,7 @@ bool ParserShowTablesQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expec
     ParserKeyword s_cluster("CLUSTER");
     ParserKeyword s_dictionaries("DICTIONARIES");
     ParserKeyword s_settings("SETTINGS");
+    ParserKeyword s_changed("CHANGED");
     ParserKeyword s_from("FROM");
     ParserKeyword s_in("IN");
     ParserKeyword s_not("NOT");
@@ -100,11 +101,19 @@ bool ParserShowTablesQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expec
 
         query->cluster_str = std::move(cluster_str);
     }
-    else if (s_settings.ignore(pos))
+    else if (bool changed = s_changed.ignore(pos); changed || s_settings.ignore(pos))
     {
         query->m_settings = true;
 
-        if (bool insensitive = s_ilike.ignore(pos, expected); insensitive || s_like.ignore(pos, expected))
+        if (changed)
+        {
+            query->changed = true;
+            if (!s_settings.ignore(pos, expected))
+                return false;
+        }
+
+        /// Not expected due to "SHOW SETTINGS PROFILES"
+        if (bool insensitive = s_ilike.ignore(pos); insensitive || s_like.ignore(pos))
         {
             if (insensitive)
                 query->case_insensitive_like = true;
@@ -112,6 +121,8 @@ bool ParserShowTablesQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expec
             if (!like_p.parse(pos, like, expected))
                 return false;
         }
+        else
+            return false;
     }
     else
     {

tests/queries/0_stateless/01293_show_settings.reference

@@ -1 +1,12 @@
 send_timeout	Seconds	300
+insert_in_memory_parts_timeout	Milliseconds	600000
+distributed_aggregation_memory_efficient	Bool	0
+aggregation_memory_efficient_merge_threads	UInt64	0
+memory_tracker_fault_probability	Float	0
+max_memory_usage	UInt64	10000000000
+max_memory_usage_for_user	UInt64	0
+max_untracked_memory	UInt64	4194304
+memory_profiler_step	UInt64	0
+memory_profiler_sample_probability	Float	0
+max_memory_usage_for_all_queries	UInt64	0
+max_memory_usage	UInt64	10000000000

tests/queries/0_stateless/01293_show_settings.sql

@@ -1 +1,5 @@
 show settings like 'send_timeout';
+SHOW SETTINGS ILIKE '%MEMORY%';
+SHOW CHANGED SETTINGS ILIKE '%MEMORY%';
+
+