Attempt to fix regression: missing support for remote tables in IN section when querying Distributed tables [#CLICKHOUSE-2]

dbms/src/Interpreters/ExpressionAnalyzer.cpp

@@ -61,6 +61,8 @@
 #include <DataTypes/DataTypeFunction.h>
 #include <Functions/FunctionsMiscellaneous.h>
 
+#include <Core/iostream_debug_helpers.h>
+
 
 namespace DB
 {
@@ -2438,6 +2440,9 @@ bool ExpressionAnalyzer::appendWhere(ExpressionActionsChain & chain, bool only_t
     initChain(chain, source_columns);
     ExpressionActionsChain::Step & step = chain.steps.back();
 
+    DUMP(only_types);
+    DUMP(StackTrace().toString());
+
     step.required_output.push_back(select_query->where_expression->getColumnName());
     getRootActions(select_query->where_expression, only_types, false, step.actions);
 

dbms/src/Interpreters/InterpreterSelectQuery.cpp

@@ -676,7 +676,8 @@ QueryProcessingStage::Enum InterpreterSelectQuery::executeFetchColumns(Pipeline
             pipeline.streams = storage->read(required_columns, query_info, context, from_stage, max_block_size, max_streams);
 
         if (pipeline.streams.empty())
-            pipeline.streams.emplace_back(std::make_shared<NullBlockInputStream>(storage->getSampleBlockForColumns(required_columns)));
+            pipeline.streams.emplace_back(std::make_shared<NullBlockInputStream>(
+                storage->analyze(required_columns, query_info, context, from_stage)));
 
         pipeline.transform([&](auto & stream)
         {

dbms/src/Storages/IStorage.h

@@ -180,6 +180,20 @@ public:
         throw Exception("Method read is not supported by storage " + getName(), ErrorCodes::NOT_IMPLEMENTED);
     }
 
+    /** Without executing a query determine,
+      *  what structure of result and what query processed stage
+      *  we will get if we will call 'read' method.
+      */
+    virtual Block analyze(
+        const Names & column_names,
+        const SelectQueryInfo & /*query_info*/,
+        const Context & /*context*/,
+        QueryProcessingStage::Enum & processed_stage)
+    {
+        processed_stage = QueryProcessingStage::FetchColumns;
+        return getSampleBlockForColumns(column_names);
+    }
+
     /** Writes the data to a table.
       * Receives a description of the query, which can contain information about the data write method.
       * Returns an object by which you can write data sequentially.

dbms/src/Storages/StorageDistributed.cpp

@@ -197,6 +197,26 @@ BlockInputStreams StorageDistributed::read(
 }
 
 
+Block StorageDistributed::analyze(
+    const Names & /*column_names*/,
+    const SelectQueryInfo & query_info,
+    const Context & context,
+    QueryProcessingStage::Enum & processed_stage)
+{
+    auto cluster = getCluster();
+
+    const Settings & settings = context.getSettingsRef();
+
+    size_t result_size = (cluster->getRemoteShardCount() * settings.max_parallel_replicas) + cluster->getLocalShardCount();
+
+    processed_stage = result_size == 1 || settings.distributed_group_by_no_merge
+        ? QueryProcessingStage::Complete
+        : QueryProcessingStage::WithMergeableState;
+
+    return materializeBlock(InterpreterSelectQuery(query_info.query, context, {}, processed_stage).getSampleBlock());
+}
+
+
 BlockOutputStreamPtr StorageDistributed::write(const ASTPtr & query, const Settings & settings)
 {
     auto cluster = (owned_cluster) ? owned_cluster : context.getCluster(cluster_name);

dbms/src/Storages/StorageDistributed.h

@@ -60,6 +60,12 @@ public:
         size_t max_block_size,
         unsigned num_streams) override;
 
+    Block analyze(
+        const Names & column_names,
+        const SelectQueryInfo & query_info,
+        const Context & context,
+        QueryProcessingStage::Enum & processed_stage) override;
+
     BlockOutputStreamPtr write(const ASTPtr & query, const Settings & settings) override;
 
     void drop() override {}