Improve schema inference for insert select from table functions

src/Interpreters/Context.cpp

@@ -31,6 +31,7 @@
 #include <Disks/DiskLocal.h>
 #include <Disks/IDiskRemote.h>
 #include <TableFunctions/TableFunctionFactory.h>
+#include <TableFunctions/TableFunctionInput.h>
 #include <Interpreters/ActionLocksManager.h>
 #include <Interpreters/ExternalLoaderXMLConfigRepository.h>
 #include <Core/Settings.h>
@@ -1092,6 +1093,17 @@ StoragePtr Context::executeTableFunction(const ASTPtr & table_expression)
     if (!res)
     {
         TableFunctionPtr table_function_ptr = TableFunctionFactory::instance().get(table_expression, shared_from_this());
+        if (table_function_ptr->needStructureHint())
+        {
+            const auto & insertion_table = getInsertionTable();
+            if (!insertion_table.empty())
+            {
+                const auto & structure_hint
+                    = DatabaseCatalog::instance().getTable(insertion_table, shared_from_this())->getInMemoryMetadataPtr()->columns;
+                table_function_ptr->setStructureHint(structure_hint);
+            }
+        }
+
         res = table_function_ptr->execute(table_expression, shared_from_this(), table_function_ptr->getName());
 
         /// Since ITableFunction::parseArguments() may change table_expression, i.e.:

src/Interpreters/Context.h

@@ -15,6 +15,7 @@
 #include <Common/isLocalAddress.h>
 #include <base/types.h>
 #include <Storages/MergeTree/ParallelReplicasReadingCoordinator.h>
+#include <Storages/ColumnsDescription.h>
 
 
 #include "config_core.h"

src/TableFunctions/TableFunctionInput.cpp

@@ -18,6 +18,7 @@ namespace ErrorCodes
 {
     extern const int LOGICAL_ERROR;
     extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
+    extern const int CANNOT_EXTRACT_TABLE_STRUCTURE;
 }
 
 void TableFunctionInput::parseArguments(const ASTPtr & ast_function, ContextPtr context)
@@ -29,6 +30,12 @@ void TableFunctionInput::parseArguments(const ASTPtr & ast_function, ContextPtr
 
     auto args = function->arguments->children;
 
+    if (args.empty())
+    {
+        structure = "auto";
+        return;
+    }
+
     if (args.size() != 1)
         throw Exception("Table function '" + getName() + "' requires exactly 1 argument: structure",
             ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
@@ -38,6 +45,16 @@ void TableFunctionInput::parseArguments(const ASTPtr & ast_function, ContextPtr
 
 ColumnsDescription TableFunctionInput::getActualTableStructure(ContextPtr context) const
 {
+    if (structure == "auto")
+    {
+        if (structure_hint.empty())
+            throw Exception(
+                ErrorCodes::CANNOT_EXTRACT_TABLE_STRUCTURE,
+                "Table function '{}' was used without structure argument but structure could not be determined automatically. Please, "
+                "provide structure manually",
+                getName());
+        return structure_hint;
+    }
     return parseColumnsListFromString(structure, context);
 }
 

src/TableFunctions/TableFunctionInput.h

@@ -16,6 +16,8 @@ class TableFunctionInput : public ITableFunction
     static constexpr auto name = "input";
     std::string getName() const override { return name; }
     bool hasStaticStructure() const override { return true; }
+    bool needStructureHint() const override { return true; }
+    void setStructureHint(const ColumnsDescription & structure_hint_) override { structure_hint = structure_hint_; }
 
 private:
     StoragePtr executeImpl(const ASTPtr & ast_function, ContextPtr context, const std::string & table_name, ColumnsDescription cached_columns) const override;
@@ -25,6 +27,7 @@ class TableFunctionInput : public ITableFunction
     void parseArguments(const ASTPtr & ast_function, ContextPtr context) override;
 
     String structure;
+    ColumnsDescription structure_hint;
 };
 
 }

tests/queries/0_stateless/01825_type_json_schema_inference.reference

@@ -5,4 +5,4 @@ Tuple(k1 Int8, k2 Tuple(k3 String, k4 Nested(k5 Int8, k6 Int8)), some Int8)
 {"id":"2","obj":"bbb","s":"bar"}
 {"map":{"k1":1,"k2":2},"obj":{"k1":1,"k2.k3":2},"map_type":"Map(String, Nullable(Float64))","obj_type":"Object('json')"}
 {"obj":{"k1":1,"k2":2},"map":{"k1":"1","k2":"2"}}
-Tuple(k1 Float64, k2 Float64)
+Tuple(k1 Int8, k2 Int8)

tests/queries/0_stateless/02249_insert_select_from_input_schema_inference.reference

@@ -0,0 +1,2 @@
+1	string1
+2	string2

tests/queries/0_stateless/02249_insert_select_from_input_schema_inference.sql

@@ -0,0 +1,5 @@
+drop table if exists test_02249;
+create table test_02249 (x UInt32, y String) engine=Memory();
+insert into test_02249 select * from input() format JSONEachRow {"x" : 1, "y" : "string1"}, {"y" : "string2", "x" : 2};
+select * from test_02249;
+drop table test_02249;

tests/queries/0_stateless/02250_insert_select_from_file_schema_inference.reference

@@ -0,0 +1 @@
+\N

tests/queries/0_stateless/02250_insert_select_from_file_schema_inference.sql

@@ -0,0 +1,6 @@
+insert into table function file('data_02250.jsonl') select NULL as x settings engine_file_truncate_on_insert=1;
+drop table if exists test_02250;
+create table test_02250 (x Nullable(UInt32)) engine=Memory();
+insert into test_02250 select * from file('data_02250.jsonl');
+select * from test_02250;
+drop table test_02250;