Backport #46771 to 23.2: More concise logging at trace level for PREWHERE steps

src/Storages/MergeTree/MergeTreeBaseSelectProcessor.cpp

@@ -79,7 +79,13 @@ IMergeTreeSelectAlgorithm::IMergeTreeSelectAlgorithm(
     result_header = header_without_const_virtual_columns;
     injectPartConstVirtualColumns(0, result_header, nullptr, partition_value_type, virt_column_names);
 
-    LOG_TEST(log, "PREWHERE actions: {}", (prewhere_actions ? prewhere_actions->dump() : std::string("<nullptr>")));
+    if (prewhere_actions)
+        LOG_TRACE(log, "PREWHERE condition was split into {} steps: {}", prewhere_actions->steps.size(), prewhere_actions->dumpConditions());
+
+    if (prewhere_info)
+        LOG_TEST(log, "Original PREWHERE DAG:\n{}\nPREWHERE actions:\n{}",
+            (prewhere_info->prewhere_actions ? prewhere_info->prewhere_actions->dumpDAG(): std::string("<nullptr>")),
+            (prewhere_actions ? prewhere_actions->dump() : std::string("<nullptr>")));
 }
 
 bool tryBuildPrewhereSteps(PrewhereInfoPtr prewhere_info, const ExpressionActionsSettings & actions_settings, PrewhereExprInfo & prewhere);

src/Storages/MergeTree/MergeTreeRangeReader.cpp

@@ -1430,4 +1430,14 @@ std::string PrewhereExprInfo::dump() const
     return s.str();
 }
 
+std::string PrewhereExprInfo::dumpConditions() const
+{
+    WriteBufferFromOwnString s;
+
+    for (size_t i = 0; i < steps.size(); ++i)
+        s << (i == 0 ? "\"" : ", \"") << steps[i].column_name << "\"";
+
+    return s.str();
+}
+
 }

src/Storages/MergeTree/MergeTreeRangeReader.h

@@ -35,6 +35,8 @@ struct PrewhereExprInfo
     std::vector<PrewhereExprStep> steps;
 
     std::string dump() const;
+
+    std::string dumpConditions() const;
 };
 
 class FilterWithCachedCount

src/Storages/MergeTree/MergeTreeSplitPrewhereIntoReadSteps.cpp

@@ -197,10 +197,6 @@ bool tryBuildPrewhereSteps(PrewhereInfoPtr prewhere_info, const ExpressionAction
     if (!prewhere_info || !prewhere_info->prewhere_actions)
         return true;
 
-    Poco::Logger * log = &Poco::Logger::get("tryBuildPrewhereSteps");
-
-    LOG_TRACE(log, "Original PREWHERE DAG:\n{}", prewhere_info->prewhere_actions->dumpDAG());
-
     /// 1. List all condition nodes that are combined with AND into PREWHERE condition
     const auto & condition_root = prewhere_info->prewhere_actions->findInOutputs(prewhere_info->prewhere_column_name);
     const bool is_conjunction = (condition_root.type == ActionsDAG::ActionType::FUNCTION && condition_root.function_base->getName() == "and");
@@ -339,8 +335,6 @@ bool tryBuildPrewhereSteps(PrewhereInfoPtr prewhere_info, const ExpressionAction
         prewhere.steps.back().need_filter = prewhere_info->need_filter;
     }
 
-    LOG_TRACE(log, "Resulting PREWHERE:\n{}", prewhere.dump());
-
     return true;
 }
 

tests/queries/0_stateless/02532_send_logs_level_test.reference

@@ -1,3 +1,2 @@
-<Test> MergeTreeBaseSelectProcessor: PREWHERE actions: <nullptr>
 <Test> MergeTreeRangeReader: First reader returned: num_rows: 1, columns: 1, total_rows_per_granule: 1, no filter, column[0]:  Int32(size = 1), requested columns: key
 <Test> MergeTreeRangeReader: read() returned num_rows: 1, columns: 1, total_rows_per_granule: 1, no filter, column[0]:  Int32(size = 1), sample block key