Don't limit the size of internal queries (this is for cache dictionaries with...

Don't limit the size of internal queries (this is for cache dictionaries with ClickHouse source) [#CLICKHOUSE-2].

dbms/src/Dictionaries/ClickHouseDictionarySource.cpp

@@ -97,7 +97,7 @@ std::string ClickHouseDictionarySource::toString() const
 }
 
 
-BlockInputStreamPtr ClickHouseDictionarySource::createStreamForSelectiveLoad(const std::string query)
+BlockInputStreamPtr ClickHouseDictionarySource::createStreamForSelectiveLoad(const std::string & query)
 {
     if (is_local)
         return executeQuery(query, context, true).in;

dbms/src/Dictionaries/ClickHouseDictionarySource.h

@@ -41,7 +41,7 @@ public:
     std::string toString() const override;
 
 private:
-    BlockInputStreamPtr createStreamForSelectiveLoad(const std::string query);
+    BlockInputStreamPtr createStreamForSelectiveLoad(const std::string & query);
 
     const DictionaryStructure dict_struct;
     const std::string host;

dbms/src/Interpreters/executeQuery.cpp

@@ -135,10 +135,15 @@ static std::tuple<ASTPtr, BlockIO> executeQueryImpl(
     ParserQuery parser(end);
     ASTPtr ast;
     size_t query_size;
-    size_t max_query_size = settings.max_query_size;
+
+    /// Don't limit the size of internal queries.
+    size_t max_query_size = 0;
+    if (!internal)
+        max_query_size = settings.max_query_size;
 
     try
     {
+        /// TODO Parser should fail early when max_query_size limit is reached.
         ast = parseQuery(parser, begin, end, "");
 
         /// Copy query into string. It will be written to log and presented in processlist. If an INSERT query, string will not include data to insertion.
@@ -150,9 +155,9 @@ static std::tuple<ASTPtr, BlockIO> executeQueryImpl(
     }
     catch (...)
     {
-        /// Anyway log query.
         if (!internal)
         {
+            /// Anyway log the query.
             String query = String(begin, begin + std::min(end - begin, static_cast<ptrdiff_t>(max_query_size)));
             logQuery(query.substr(0, settings.log_queries_cut_to_length), context);
             onExceptionBeforeStart(query, context, current_time);