fix sample with final

src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp

@@ -601,6 +601,11 @@ Pipes MergeTreeDataSelectExecutor::readFromParts(
         .save_marks_in_cache = true
     };
 
+    /// Projection, that needed to drop columns, which have appeared by execution
+    /// of some extra expressions, and to allow execute the same expressions later.
+    /// NOTE: It may lead to double computation of expressions.
+    ExpressionActionsPtr result_projection;
+
     if (select.final())
     {
         /// Add columns needed to calculate the sorting expression and the sign.
@@ -623,7 +628,8 @@ Pipes MergeTreeDataSelectExecutor::readFromParts(
             query_info,
             virt_column_names,
             settings,
-            reader_settings);
+            reader_settings,
+            result_projection);
     }
     else if (settings.optimize_read_in_order && query_info.input_sorting_info)
     {
@@ -644,7 +650,8 @@ Pipes MergeTreeDataSelectExecutor::readFromParts(
             sorting_key_prefix_expr,
             virt_column_names,
             settings,
-            reader_settings);
+            reader_settings,
+            result_projection);
     }
     else
     {
@@ -667,6 +674,13 @@ Pipes MergeTreeDataSelectExecutor::readFromParts(
                     pipe.getHeader(), filter_expression, filter_function->getColumnName(), false));
     }
 
+    if (result_projection)
+    {
+        for (auto & pipe : res)
+            pipe.addSimpleTransform(std::make_shared<ExpressionTransform>(
+                pipe.getHeader(), result_projection));
+    }
+
     /// By the way, if a distributed query or query to a Merge table is made, then the `_sample_factor` column can have different values.
     if (sample_factor_column_queried)
     {
@@ -831,7 +845,8 @@ Pipes MergeTreeDataSelectExecutor::spreadMarkRangesAmongStreamsWithOrder(
     const ExpressionActionsPtr & sorting_key_prefix_expr,
     const Names & virt_columns,
     const Settings & settings,
-    const MergeTreeReaderSettings & reader_settings) const
+    const MergeTreeReaderSettings & reader_settings,
+    ExpressionActionsPtr & out_projection) const
 {
     size_t sum_marks = 0;
     const InputSortingInfoPtr & input_sorting_info = query_info.input_sorting_info;
@@ -1007,19 +1022,14 @@ Pipes MergeTreeDataSelectExecutor::spreadMarkRangesAmongStreamsWithOrder(
                 sort_description.emplace_back(data.sorting_key_columns[j],
                     input_sorting_info->direction, 1);
 
-            /// Project input columns to drop columns from sorting_key_prefix_expr
+            out_projection = createProjection(pipes.back(), data);
-            /// to allow execute the same expression later.
-            /// NOTE: It may lead to double computation of expression.
-            auto projection = createProjection(pipes.back(), data);
             for (auto & pipe : pipes)
                 pipe.addSimpleTransform(std::make_shared<ExpressionTransform>(pipe.getHeader(), sorting_key_prefix_expr));
 
             auto merging_sorted = std::make_shared<MergingSortedTransform>(
                 pipes.back().getHeader(), pipes.size(), sort_description, max_block_size);
 
-            Pipe merged(std::move(pipes), std::move(merging_sorted));
+            res.emplace_back(std::move(pipes), std::move(merging_sorted));
-            merged.addSimpleTransform(std::make_shared<ExpressionTransform>(merged.getHeader(), projection));
-            res.emplace_back(std::move(merged));
         }
         else
             res.emplace_back(std::move(pipes.front()));
@@ -1037,7 +1047,8 @@ Pipes MergeTreeDataSelectExecutor::spreadMarkRangesAmongStreamsFinal(
     const SelectQueryInfo & query_info,
     const Names & virt_columns,
     const Settings & settings,
-    const MergeTreeReaderSettings & reader_settings) const
+    const MergeTreeReaderSettings & reader_settings,
+    ExpressionActionsPtr & out_projection) const
 {
     const auto data_settings = data.getSettings();
     size_t sum_marks = 0;
@@ -1065,10 +1076,6 @@ Pipes MergeTreeDataSelectExecutor::spreadMarkRangesAmongStreamsFinal(
         use_uncompressed_cache = false;
 
     Pipes pipes;
-    /// Project input columns to drop columns from sorting_key_expr
-    /// to allow execute the same expression later.
-    /// NOTE: It may lead to double computation of expression.
-    ExpressionActionsPtr projection;
 
     for (const auto & part : parts)
     {
@@ -1079,8 +1086,8 @@ Pipes MergeTreeDataSelectExecutor::spreadMarkRangesAmongStreamsFinal(
             virt_columns, part.part_index_in_query);
 
         Pipe pipe(std::move(source_processor));
-        if (!projection)
+        if (!out_projection)
-            projection = createProjection(pipe, data);
+            out_projection = createProjection(pipe, data);
 
         pipe.addSimpleTransform(std::make_shared<ExpressionTransform>(pipe.getHeader(), data.sorting_key_expr));
         pipes.emplace_back(std::move(pipe));
@@ -1154,7 +1161,6 @@ Pipes MergeTreeDataSelectExecutor::spreadMarkRangesAmongStreamsFinal(
     if (merged_processor)
     {
         Pipe pipe(std::move(pipes), std::move(merged_processor));
-        pipe.addSimpleTransform(std::make_shared<ExpressionTransform>(pipe.getHeader(), projection));
         pipes = Pipes();
         pipes.emplace_back(std::move(pipe));
     }

src/Storages/MergeTree/MergeTreeDataSelectExecutor.h

@@ -67,7 +67,8 @@ private:
         const ExpressionActionsPtr & sorting_key_prefix_expr,
         const Names & virt_columns,
         const Settings & settings,
-        const MergeTreeReaderSettings & reader_settings) const;
+        const MergeTreeReaderSettings & reader_settings,
+        ExpressionActionsPtr & out_projection) const;
 
     Pipes spreadMarkRangesAmongStreamsFinal(
         RangesInDataParts && parts,
@@ -77,7 +78,8 @@ private:
         const SelectQueryInfo & query_info,
         const Names & virt_columns,
         const Settings & settings,
-        const MergeTreeReaderSettings & reader_settings) const;
+        const MergeTreeReaderSettings & reader_settings,
+        ExpressionActionsPtr & out_projection) const;
 
     /// Get the approximate value (bottom estimate - only by full marks) of the number of rows falling under the index.
     size_t getApproximateTotalRowsToRead(

tests/queries/0_stateless/01137_sample_final.reference

@@ -0,0 +1,10 @@
+8	8
+9	9
+10	10
+14	14
+15	15
+9140302661501632497
+9199082625845137542
+8769270213041934496
+4926958392161000708
+89922286675368115

tests/queries/0_stateless/01137_sample_final.sql

@@ -0,0 +1,13 @@
+drop table if exists tab;
+
+create table tab (x UInt64, v UInt64) engine = ReplacingMergeTree(v) order by (x, sipHash64(x)) sample by sipHash64(x);
+insert into tab select number, number from numbers(1000);
+select * from tab final sample 1/2 order by x limit 5;
+
+drop table tab;
+
+create table tab (x UInt64, v UInt64) engine = ReplacingMergeTree(v) order by (x, sipHash64(x)) sample by sipHash64(x);
+insert into tab select number, number from numbers(1000);
+select sipHash64(x) from tab sample 1/2 order by x, sipHash64(x) limit 5;
+
+drop table tab;