From f37599112a9a6e8949db03eee65681d2588c0061 Mon Sep 17 00:00:00 2001
From: Maksim Kita <kitaetoya@gmail.com>
Date: Mon, 26 Apr 2021 23:36:15 +0300
Subject: [PATCH] Added EXCHANGE DICTIONARIES query support

---
 src/Databases/DatabaseAtomic.cpp  | 14 +++++++++-----
 src/Parsers/ParserRenameQuery.cpp |  6 ++++++
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/Databases/DatabaseAtomic.cpp b/src/Databases/DatabaseAtomic.cpp
index 2a22b08627c..9a40c6550e8 100644
--- a/src/Databases/DatabaseAtomic.cpp
+++ b/src/Databases/DatabaseAtomic.cpp
@@ -159,8 +159,6 @@ void DatabaseAtomic::renameTable(ContextPtr local_context, const String & table_
         return;
     }
 
-    if (exchange && dictionary)
-        throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Cannot exchange dictionaries");
     if (exchange && !supportsRenameat2())
         throw Exception(ErrorCodes::NOT_IMPLEMENTED, "RENAME EXCHANGE is not supported");
 
@@ -230,9 +228,15 @@ void DatabaseAtomic::renameTable(ContextPtr local_context, const String & table_
 
     StoragePtr table = getTableUnlocked(table_name, db_lock);
 
-    if (dictionary != table->isDictionary())
-        throw Exception(ErrorCodes::INCORRECT_QUERY,
-                        "Use RENAME DICTIONARY for dictionaries and RENAME TABLE for tables.");
+    if (table->isDictionary() && !dictionary)
+    {
+        if (exchange)
+            throw Exception(ErrorCodes::INCORRECT_QUERY,
+                "Use EXCHANGE DICTIONARIES for dictionaries and EXCAHNGE TABLES for tables.");
+        else
+            throw Exception(ErrorCodes::INCORRECT_QUERY,
+                "Use RENAME DICTIONARY for dictionaries and RENAME TABLE for tables.");
+    }
 
     table->checkTableCanBeRenamed();
     assert_can_move_mat_view(table);
diff --git a/src/Parsers/ParserRenameQuery.cpp b/src/Parsers/ParserRenameQuery.cpp
index 7fa4e6e5408..e3b35249cd6 100644
--- a/src/Parsers/ParserRenameQuery.cpp
+++ b/src/Parsers/ParserRenameQuery.cpp
@@ -42,6 +42,7 @@ bool ParserRenameQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
     ParserKeyword s_rename_table("RENAME TABLE");
     ParserKeyword s_exchange_tables("EXCHANGE TABLES");
     ParserKeyword s_rename_dictionary("RENAME DICTIONARY");
+    ParserKeyword s_exchange_dictionaries("EXCHANGE DICTIONARIES");
     ParserKeyword s_rename_database("RENAME DATABASE");
     ParserKeyword s_to("TO");
     ParserKeyword s_and("AND");
@@ -56,6 +57,11 @@ bool ParserRenameQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
         exchange = true;
     else if (s_rename_dictionary.ignore(pos, expected))
         dictionary = true;
+    else if (s_exchange_dictionaries.ignore(pos, expected))
+    {
+        exchange = true;
+        dictionary = true;
+    }
     else if (s_rename_database.ignore(pos, expected))
     {
         ASTPtr from_db;