TTL Expressions WHERE and GROUP BY draft

src/DataStreams/TTLBlockInputStream.cpp

@@ -67,6 +67,30 @@ TTLBlockInputStream::TTLBlockInputStream(
             default_expr_list, storage.getColumns().getAllPhysical());
         defaults_expression = ExpressionAnalyzer{default_expr_list, syntax_result, storage.global_context}.getActions(true);
     }
+
+    if (storage.hasRowsTTL() && !storage.rows_ttl_entry.group_by_keys.empty())
+    {
+        ColumnNumbers keys;
+        for (const auto & key : storage.rows_ttl_entry.group_by_keys)
+            keys.push_back(header.getPositionByName(key));
+        agg_key_columns.resize(storage.rows_ttl_entry.group_by_keys.size());
+
+        AggregateDescriptions aggregates = storage.rows_ttl_entry.aggregate_descriptions;
+        for (auto & descr : aggregates)
+            if (descr.arguments.empty())
+                for (const auto & name : descr.argument_names)
+                    descr.arguments.push_back(header.getPositionByName(name));
+        agg_aggregate_columns.resize(storage.rows_ttl_entry.aggregate_descriptions.size());
+
+        const Settings & settings = storage.global_context.getSettingsRef();
+
+        Aggregator::Params params(header, keys, aggregates,
+            false, settings.max_rows_to_group_by, settings.group_by_overflow_mode,
+            SettingUInt64(0), SettingUInt64(0),
+            settings.max_bytes_before_external_group_by, settings.empty_result_for_aggregation_by_empty_set,
+            storage.global_context.getTemporaryVolume(), settings.max_threads, settings.min_free_disk_space_for_temporary_data);
+        aggregator = std::make_unique<Aggregator>(params);
+    }
 }
 
 bool TTLBlockInputStream::isTTLExpired(time_t ttl) const
@@ -77,7 +101,8 @@ bool TTLBlockInputStream::isTTLExpired(time_t ttl) const
 Block TTLBlockInputStream::readImpl()
 {
     /// Skip all data if table ttl is expired for part
-    if (storage.hasRowsTTL() && isTTLExpired(old_ttl_infos.table_ttl.max))
+    if (storage.hasRowsTTL() && !storage.rows_ttl_entry.where_expression &&
+        storage.rows_ttl_entry.group_by_keys.empty() && isTTLExpired(old_ttl_infos.table_ttl.max))
     {
         rows_removed = data_part->rows_count;
         return {};
@@ -85,7 +110,43 @@ Block TTLBlockInputStream::readImpl()
 
     Block block = children.at(0)->read();
     if (!block)
+    {
+        if (aggregator && !agg_result.empty())
+        {
+            MutableColumns result_columns;
+            const auto & column_names = header.getNames();
+            for (const auto & column_name : column_names)
+            {
+                const IColumn * values_column = header.getByName(column_name).column.get();
+                MutableColumnPtr result_column = values_column->cloneEmpty();
+                result_columns.emplace_back(std::move(result_column));
+            }
+
+            auto aggregated_res = aggregator->convertToBlocks(agg_result, true, 1);
+            for (auto & agg_block : aggregated_res)
+            {
+                for (const auto & [name, actions] : storage.rows_ttl_entry.group_by_aggregations)
+                    actions->execute(agg_block);
+                for (const auto & name : storage.rows_ttl_entry.group_by_keys)
+                {
+                    const IColumn * values_column = agg_block.getByName(name).column.get();
+                    auto & result_column = result_columns[header.getPositionByName(name)];
+                    result_column->insertRangeFrom(*values_column, 0, agg_block.rows());
+                }
+                for (const auto & [name, res_column] : storage.rows_ttl_entry.group_by_aggregations_res_column)
+                {
+                    const IColumn * values_column = agg_block.getByName(res_column).column.get();
+                    auto & result_column = result_columns[header.getPositionByName(name)];
+                    result_column->insertRangeFrom(*values_column, 0, agg_block.rows());
+                }
+            }
+
+            block = header.cloneWithColumns(std::move(result_columns));
+            agg_result.invalidate();
+        }
+
         return block;
+    }
 
     if (storage.hasRowsTTL() && (force || isTTLExpired(old_ttl_infos.table_ttl.min)))
         removeRowsWithExpiredTableTTL(block);
@@ -114,14 +175,21 @@ void TTLBlockInputStream::readSuffixImpl()
 void TTLBlockInputStream::removeRowsWithExpiredTableTTL(Block & block)
 {
     storage.rows_ttl_entry.expression->execute(block);
+    if (storage.rows_ttl_entry.where_expression)
+        storage.rows_ttl_entry.where_expression->execute(block);
 
     const IColumn * ttl_column =
         block.getByName(storage.rows_ttl_entry.result_column).column.get();
 
+    const IColumn * where_filter_column = storage.rows_ttl_entry.where_expression ?
+        block.getByName(storage.rows_ttl_entry.where_filter_column).column.get() : nullptr;
+
     const auto & column_names = header.getNames();
+
+    if (!aggregator)
+    {
         MutableColumns result_columns;
         result_columns.reserve(column_names.size());
-
         for (auto it = column_names.begin(); it != column_names.end(); ++it)
         {
             const IColumn * values_column = block.getByName(*it).column.get();
@@ -131,7 +199,8 @@ void TTLBlockInputStream::removeRowsWithExpiredTableTTL(Block & block)
             for (size_t i = 0; i < block.rows(); ++i)
             {
                 UInt32 cur_ttl = getTimestampByIndex(ttl_column, i);
-            if (!isTTLExpired(cur_ttl))
+                bool where_filter_passed = !where_filter_column || where_filter_column->getBool(i);
+                if (!isTTLExpired(cur_ttl) || !where_filter_passed)
                 {
                     new_ttl_infos.table_ttl.update(cur_ttl);
                     result_column->insertFrom(*values_column, i);
@@ -141,9 +210,137 @@ void TTLBlockInputStream::removeRowsWithExpiredTableTTL(Block & block)
             }
             result_columns.emplace_back(std::move(result_column));
         }
+        block = header.cloneWithColumns(std::move(result_columns));
+    }
+    else
+    {
+        MutableColumns result_columns;
+        MutableColumns aggregate_columns;
+
+        for (const auto & column_name : column_names)
+        {
+            const IColumn * values_column = block.getByName(column_name).column.get();
+            MutableColumnPtr result_column = values_column->cloneEmpty();
+            result_column->reserve(block.rows());
+            result_columns.emplace_back(std::move(result_column));
+
+            MutableColumnPtr aggregate_column = values_column->cloneEmpty();
+            aggregate_column->reserve(block.rows());
+            aggregate_columns.emplace_back(std::move(aggregate_column));
+        }
+
+        size_t rows_aggregated = 0;
+        size_t current_key_start = 0;
+        size_t rows_with_current_key = 0; 
+        for (size_t i = 0; i < block.rows(); ++i)
+        {
+            UInt32 cur_ttl = getTimestampByIndex(ttl_column, i);
+            bool where_filter_passed = !where_filter_column || where_filter_column->getBool(i);
+            bool ttl_expired = isTTLExpired(cur_ttl) && where_filter_passed;
+
+            bool same_as_current = true;
+            if (current_key_value.empty())
+            {
+                same_as_current = false;
+                current_key_value.resize(storage.rows_ttl_entry.group_by_keys.size());
+            }
+            for (size_t j = 0; j < storage.rows_ttl_entry.group_by_keys.size(); ++j)
+            {
+                const String & key_column = storage.rows_ttl_entry.group_by_keys[j];
+                const IColumn * values_column = block.getByName(key_column).column.get();
+                if (!same_as_current)
+                    values_column->get(i, current_key_value[j]);
+                else
+                {
+                    Field value;
+                    values_column->get(i, value);
+                    if (value != current_key_value[j])
+                    {
+                        current_key_value[j] = value;
+                        same_as_current = false;
+                    }
+                }
+            }
+            if (!same_as_current)
+            {
+                if (rows_with_current_key)
+                {
+                    Columns aggregate_chunk;
+                    aggregate_chunk.reserve(aggregate_columns.size());
+                    for (const auto & name : column_names)
+                    {
+                        const auto & column = aggregate_columns[header.getPositionByName(name)];
+                        ColumnPtr chunk_column = column->cut(current_key_start, rows_with_current_key);
+                        aggregate_chunk.emplace_back(std::move(chunk_column));
+                    }
+                    aggregator->executeOnBlock(aggregate_chunk, rows_with_current_key, agg_result, agg_key_columns,
+                                            agg_aggregate_columns, agg_no_more_keys);
+                }
+                if (!agg_result.empty())
+                {
+                    auto aggregated_res = aggregator->convertToBlocks(agg_result, true, 1);
+                    for (auto & agg_block : aggregated_res)
+                    {
+                        for (const auto & [name, actions] : storage.rows_ttl_entry.group_by_aggregations)
+                            actions->execute(agg_block);
+                        for (const auto & name : storage.rows_ttl_entry.group_by_keys)
+                        {
+                            const IColumn * values_column = agg_block.getByName(name).column.get();
+                            auto & result_column = result_columns[header.getPositionByName(name)];
+                            result_column->insertRangeFrom(*values_column, 0, agg_block.rows());
+                        }
+                        for (const auto & [name, res_column] : storage.rows_ttl_entry.group_by_aggregations_res_column)
+                        {
+                            const IColumn * values_column = agg_block.getByName(res_column).column.get();
+                            auto & result_column = result_columns[header.getPositionByName(name)];
+                            result_column->insertRangeFrom(*values_column, 0, agg_block.rows());
+                        }
+                    }
+                }
+                agg_result.invalidate();
+                current_key_start = rows_aggregated;
+                rows_with_current_key = 0;
+            }
+            if (ttl_expired)
+            {
+                ++rows_with_current_key;
+                ++rows_aggregated;
+                for (const auto & name : column_names)
+                {
+                    const IColumn * values_column = block.getByName(name).column.get();
+                    auto & column = aggregate_columns[header.getPositionByName(name)];
+                    column->insertFrom(*values_column, i);
+                }
+            }
+            else
+            {
+                new_ttl_infos.table_ttl.update(cur_ttl);
+                for (const auto & name : column_names)
+                {
+                    const IColumn * values_column = block.getByName(name).column.get();
+                    auto & column = result_columns[header.getPositionByName(name)];
+                    column->insertFrom(*values_column, i);
+                }
+            }
+        }
+
+        if (rows_with_current_key)
+        {
+            Columns aggregate_chunk;
+            aggregate_chunk.reserve(aggregate_columns.size());
+            for (const auto & name : column_names)
+            {
+                const auto & column = aggregate_columns[header.getPositionByName(name)];
+                ColumnPtr chunk_column = column->cut(current_key_start, rows_with_current_key);
+                aggregate_chunk.emplace_back(std::move(chunk_column));
+            }
+            aggregator->executeOnBlock(aggregate_chunk, rows_with_current_key, agg_result, agg_key_columns,
+                                       agg_aggregate_columns, agg_no_more_keys);
+        }
 
         block = header.cloneWithColumns(std::move(result_columns));
     }
+}
 
 void TTLBlockInputStream::removeValuesWithExpiredColumnTTL(Block & block)
 {

src/DataStreams/TTLBlockInputStream.h

@@ -3,6 +3,7 @@
 #include <Storages/MergeTree/MergeTreeData.h>
 #include <Storages/MergeTree/IMergeTreeDataPart.h>
 #include <Core/Block.h>
+#include <Interpreters/Aggregator.h>
 
 #include <common/DateLUT.h>
 
@@ -39,6 +40,13 @@ private:
     time_t current_time;
     bool force;
 
+    std::unique_ptr<Aggregator> aggregator;
+    std::vector<Field> current_key_value;
+    AggregatedDataVariants agg_result;
+    ColumnRawPtrs agg_key_columns; 
+    Aggregator::AggregateColumns agg_aggregate_columns;
+    bool agg_no_more_keys;
+
     IMergeTreeDataPart::TTLInfos old_ttl_infos;
     IMergeTreeDataPart::TTLInfos new_ttl_infos;
     NameSet empty_columns;

src/Interpreters/ExpressionAnalyzer.cpp

@@ -192,10 +192,10 @@ void ExpressionAnalyzer::analyzeAggregation()
 
     if (has_aggregation)
     {
-        getSelectQuery(); /// assertSelect()
+        // getSelectQuery(); /// assertSelect()
 
         /// Find out aggregation keys.
-        if (select_query->groupBy())
+        if (select_query && select_query->groupBy())
         {
             NameSet unique_keys;
             ASTs & group_asts = select_query->groupBy()->children;
@@ -926,7 +926,10 @@ void ExpressionAnalyzer::appendExpression(ExpressionActionsChain & chain, const
 
 ExpressionActionsPtr ExpressionAnalyzer::getActions(bool add_aliases, bool project_result)
 {
-    ExpressionActionsPtr actions = std::make_shared<ExpressionActions>(sourceColumns(), context);
+    NamesAndTypesList columns(sourceColumns());
+    for (const auto & col : aggregated_columns)
+        columns.push_back(col);
+    ExpressionActionsPtr actions = std::make_shared<ExpressionActions>(columns, context);
     NamesWithAliases result_columns;
     Names result_names;
 

src/Interpreters/SyntaxAnalyzer.cpp

@@ -839,7 +839,7 @@ SyntaxAnalyzerResultPtr SyntaxAnalyzer::analyzeSelect(
     return std::make_shared<const SyntaxAnalyzerResult>(result);
 }
 
-SyntaxAnalyzerResultPtr SyntaxAnalyzer::analyze(ASTPtr & query, const NamesAndTypesList & source_columns, ConstStoragePtr storage) const
+SyntaxAnalyzerResultPtr SyntaxAnalyzer::analyze(ASTPtr & query, const NamesAndTypesList & source_columns, ConstStoragePtr storage, bool allow_aggregates) const
 {
     if (query->as<ASTSelectQuery>())
         throw Exception("Not select analyze for select asts.", ErrorCodes::LOGICAL_ERROR);
@@ -855,7 +855,20 @@ SyntaxAnalyzerResultPtr SyntaxAnalyzer::analyze(ASTPtr & query, const NamesAndTy
 
     optimizeIf(query, result.aliases, settings.optimize_if_chain_to_miltiif);
 
+    if (allow_aggregates) 
+    {
+        GetAggregatesVisitor::Data data;
+        GetAggregatesVisitor(data).visit(query);
+
+        /// There can not be other aggregate functions within the aggregate functions.
+        for (const ASTFunction * node : data.aggregates)
+            for (auto & arg : node->arguments->children)
+                assertNoAggregates(arg, "inside another aggregate function");
+        result.aggregates = data.aggregates;
+    }
+    else 
         assertNoAggregates(query, "in wrong place");
+
     result.collectUsedColumns(query);
     return std::make_shared<const SyntaxAnalyzerResult>(result);
 }

src/Interpreters/SyntaxAnalyzer.h

@@ -86,7 +86,7 @@ public:
     {}
 
     /// Analyze and rewrite not select query
-    SyntaxAnalyzerResultPtr analyze(ASTPtr & query, const NamesAndTypesList & source_columns_, ConstStoragePtr storage = {}) const;
+    SyntaxAnalyzerResultPtr analyze(ASTPtr & query, const NamesAndTypesList & source_columns_, ConstStoragePtr storage = {}, bool allow_aggregations = false) const;
 
     /// Analyze and rewrite select query
     SyntaxAnalyzerResultPtr analyzeSelect(

src/Parsers/ASTTTLElement.cpp

@@ -7,21 +7,80 @@
 namespace DB
 {
 
+ASTPtr ASTTTLElement::clone() const 
+{
+    auto clone = std::make_shared<ASTTTLElement>(*this);
+    clone->children.clear();
+    clone->positions.clear();
+    
+    for (auto expr : {Expression::TTL, Expression::WHERE})
+        clone->setExpression(expr, getExpression(expr, true));
+
+    for (auto & [name, expr] : clone->group_by_aggregations)
+        expr = expr->clone();
+
+    return clone;
+}
+
 void ASTTTLElement::formatImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const
 {
-    children.front()->formatImpl(settings, state, frame);
-    if (destination_type == PartDestinationType::DISK)
+    ttl()->formatImpl(settings, state, frame);
+    if (mode == Mode::MOVE && destination_type == PartDestinationType::DISK)
     {
         settings.ostr << " TO DISK " << quoteString(destination_name);
     }
-    else if (destination_type == PartDestinationType::VOLUME)
+    else if (mode == Mode::MOVE && destination_type == PartDestinationType::VOLUME)
     {
         settings.ostr << " TO VOLUME " << quoteString(destination_name);
     }
-    else if (destination_type == PartDestinationType::DELETE)
+    else if (mode == Mode::GROUP_BY)
+    {
+        settings.ostr << " GROUP BY ";
+        for (size_t i = 0; i < group_by_key_columns.size(); ++i)
+        {
+            settings.ostr << group_by_key_columns[i];
+            if (i + 1 != group_by_key_columns.size())
+                settings.ostr << ", ";
+        }
+        settings.ostr << " SET ";
+        for (size_t i =  0; i < group_by_aggregations.size(); ++i)
+        {
+            settings.ostr << group_by_aggregations[i].first << " = ";
+            group_by_aggregations[i].second->formatImpl(settings, state, frame);
+            if (i + 1 != group_by_aggregations.size())
+                settings.ostr << ", ";
+        }
+    }
+    else if (mode == Mode::DELETE)
     {
         /// It would be better to output "DELETE" here but that will break compatibility with earlier versions.
     }
+
+    if (where()) 
+    {
+        settings.ostr << " WHERE ";
+        where()->formatImpl(settings, state, frame);
+    }
+}
+
+void ASTTTLElement::setExpression(Expression expr, ASTPtr && ast) 
+{
+    auto it = positions.find(expr);
+    if (it == positions.end())
+    {
+        positions[expr] = children.size();
+        children.emplace_back(ast);
+    }
+    else
+        children[it->second] = ast;
+}
+
+ASTPtr ASTTTLElement::getExpression(Expression expr, bool clone) const
+{
+    auto it = positions.find(expr);
+    if (it != positions.end())
+        return clone ? children[it->second]->clone() : children[it->second];
+    return {};
 }
 
 }

src/Parsers/ASTTTLElement.h

@@ -6,31 +6,53 @@
 
 namespace DB
 {
+
 /** Element of TTL expression.
   */
 class ASTTTLElement : public IAST
 {
 public:
+    enum class Expression : uint8_t
+    {
+        TTL,
+        WHERE
+    };
+
+    enum class Mode : uint8_t
+    {
+        DELETE,
+        MOVE,
+        GROUP_BY
+    };
+
+    Mode mode;
     PartDestinationType destination_type;
     String destination_name;
+    std::vector<String> group_by_key_columns;
+    std::vector<std::pair<String, ASTPtr>> group_by_aggregations;
 
-    ASTTTLElement(PartDestinationType destination_type_, const String & destination_name_)
-        : destination_type(destination_type_)
+    ASTTTLElement(Mode mode_, PartDestinationType destination_type_, const String & destination_name_)
+        : mode(mode_) 
+        , destination_type(destination_type_)
         , destination_name(destination_name_)
     {
     }
 
     String getID(char) const override { return "TTLElement"; }
 
-    ASTPtr clone() const override
-    {
-        auto clone = std::make_shared<ASTTTLElement>(*this);
-        clone->cloneChildren();
-        return clone;
-    }
+    ASTPtr clone() const override;
+
+    const ASTPtr ttl() const { return getExpression(Expression::TTL); }
+    const ASTPtr where() const { return getExpression(Expression::WHERE); }
+
+    void setExpression(Expression expr, ASTPtr && ast);
+    ASTPtr getExpression(Expression expr, bool clone = false) const;
 
 protected:
     void formatImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const override;
+
+private:
+    std::unordered_map<Expression, size_t> positions;
 };
 
 }

src/Parsers/ExpressionElementParsers.cpp

@@ -1455,23 +1455,50 @@ bool ParserTTLElement::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
     ParserKeyword s_to_disk("TO DISK");
     ParserKeyword s_to_volume("TO VOLUME");
     ParserKeyword s_delete("DELETE");
+    ParserKeyword s_where("WHERE");
+    ParserKeyword s_group_by("GROUP BY");
+    ParserKeyword s_set("SET");
+    ParserToken s_comma(TokenType::Comma);
+    ParserToken s_eq(TokenType::Equals);
+    ParserIdentifier parser_identifier;
     ParserStringLiteral parser_string_literal;
     ParserExpression parser_exp;
+    ParserIdentifierList parser_identifier_list;
 
-    ASTPtr expr_elem;
-    if (!parser_exp.parse(pos, expr_elem, expected))
+
+    ASTPtr ttl_expr;
+    if (!parser_exp.parse(pos, ttl_expr, expected))
         return false;
 
+    ASTPtr where_expr;
+
+    std::vector<String> group_by_key_columns;
+    std::vector<std::pair<String, ASTPtr>> group_by_aggregations;
+
+    ASTTTLElement::Mode mode;
     PartDestinationType destination_type = PartDestinationType::DELETE;
     String destination_name;
     if (s_to_disk.ignore(pos))
+    {
+        mode = ASTTTLElement::Mode::MOVE;
         destination_type = PartDestinationType::DISK;
+    }
     else if (s_to_volume.ignore(pos))
+    {
+        mode = ASTTTLElement::Mode::MOVE;
         destination_type = PartDestinationType::VOLUME;
+    }
+    else if (s_group_by.ignore(pos)) 
+    {
+        mode = ASTTTLElement::Mode::GROUP_BY;
+    }
     else
+    {
         s_delete.ignore(pos);
+        mode = ASTTTLElement::Mode::DELETE;
+    }
 
-    if (destination_type == PartDestinationType::DISK || destination_type == PartDestinationType::VOLUME)
+    if (mode == ASTTTLElement::Mode::MOVE)
     {
         ASTPtr ast_space_name;
         if (!parser_string_literal.parse(pos, ast_space_name, expected))
@@ -1479,10 +1506,57 @@ bool ParserTTLElement::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
 
         destination_name = ast_space_name->as<ASTLiteral &>().value.get<const String &>();
     }
+    else if (mode == ASTTTLElement::Mode::GROUP_BY)
+    {
+        ASTPtr ast_group_by_key_columns;
+        if (!parser_identifier_list.parse(pos, ast_group_by_key_columns, expected))
+            return false;
+        for (const auto identifier : ast_group_by_key_columns->children)
+        {
+            String identifier_str;
+            if (!tryGetIdentifierNameInto(identifier, identifier_str))
+                return false;
+            group_by_key_columns.emplace_back(std::move(identifier_str));
+        }        
 
-    node = std::make_shared<ASTTTLElement>(destination_type, destination_name);
-    node->children.push_back(expr_elem);
+        if (!s_set.ignore(pos))
+            return false;
+        while (true)
+        {
+            if (!group_by_aggregations.empty() && !s_comma.ignore(pos))
+                break;
             
+            ASTPtr name;
+            ASTPtr value;
+            if (!parser_identifier.parse(pos, name, expected))
+                return false;
+            if (!s_eq.ignore(pos))
+                return false;
+            if (!parser_exp.parse(pos, value, expected))
+                return false;
+
+            String name_str;
+            if (!tryGetIdentifierNameInto(name, name_str))
+                return false;
+            group_by_aggregations.emplace_back(name_str, std::move(value));
+        }
+    }
+
+    if ((mode == ASTTTLElement::Mode::MOVE || mode == ASTTTLElement::Mode::DELETE) && s_where.ignore(pos))
+    {
+        if (!parser_exp.parse(pos, where_expr, expected))
+            return false;
+    }
+
+    auto ttl_element = std::make_shared<ASTTTLElement>(mode, destination_type, destination_name);
+    ttl_element->setExpression(ASTTTLElement::Expression::TTL, std::move(ttl_expr));
+    if (where_expr)
+        ttl_element->setExpression(ASTTTLElement::Expression::WHERE, std::move(where_expr));
+
+    ttl_element->group_by_key_columns = std::move(group_by_key_columns);
+    ttl_element->group_by_aggregations = std::move(group_by_aggregations);
+
+    node = ttl_element;
     return true;
 }
 

src/Parsers/ExpressionListParsers.cpp

@@ -742,4 +742,13 @@ bool ParserKeyValuePairsList::parseImpl(Pos & pos, ASTPtr & node, Expected & exp
     return parser.parse(pos, node, expected);
 }
 
+
+bool ParserIdentifierList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
+{
+    return ParserList(
+        std::make_unique<ParserIdentifier>(),
+        std::make_unique<ParserToken>(TokenType::Comma))
+        .parse(pos, node, expected);
+}
+
 }

src/Parsers/ExpressionListParsers.h

@@ -421,4 +421,13 @@ protected:
     bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) override;
 };
 
+
+/** A comma-separated list of identifiers, probably empty. */
+class ParserIdentifierList : public IParserBase
+{
+protected:
+    const char * getName() const override { return "list of identifiers"; }
+    bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) override;
+};
+
 }

src/Storages/MergeTree/MergeTreeData.cpp

@@ -615,19 +615,50 @@ void MergeTreeData::setTTLExpressions(const ColumnsDescription & new_columns,
 
     auto new_column_ttls = new_columns.getColumnTTLs();
 
-    auto create_ttl_entry = [this, &new_columns](ASTPtr ttl_ast)
+    auto create_ttl_entry = [this, &new_columns](ASTPtr ttl_expr_ast)
     {
         TTLEntry result;
 
-        auto syntax_result = SyntaxAnalyzer(global_context).analyze(ttl_ast, new_columns.getAllPhysical());
-        result.expression = ExpressionAnalyzer(ttl_ast, syntax_result, global_context).getActions(false);
+        auto ttl_syntax_result = SyntaxAnalyzer(global_context).analyze(ttl_expr_ast, new_columns.getAllPhysical());
+        result.expression = ExpressionAnalyzer(ttl_expr_ast, ttl_syntax_result, global_context).getActions(false);
+        result.result_column = ttl_expr_ast->getColumnName();
+
         result.destination_type = PartDestinationType::DELETE;
-        result.result_column = ttl_ast->getColumnName();
 
         checkTTLExpression(result.expression, result.result_column);
         return result;
     };
 
+    auto create_rows_ttl_entry = [this, &new_columns, &create_ttl_entry](const ASTTTLElement * ttl_element)
+    {
+        auto result = create_ttl_entry(ttl_element->ttl());
+        if (ttl_element->mode == ASTTTLElement::Mode::DELETE || ttl_element->mode ==ASTTTLElement::Mode::MOVE)         
+        {
+            if (ASTPtr where_expr_ast = ttl_element->where()) 
+            {
+                auto where_syntax_result = SyntaxAnalyzer(global_context).analyze(where_expr_ast, new_columns.getAllPhysical());
+                result.where_expression = ExpressionAnalyzer(where_expr_ast, where_syntax_result, global_context).getActions(false);
+                result.where_filter_column = where_expr_ast->getColumnName();
+            }
+        }
+        else if (ttl_element->mode == ASTTTLElement::Mode::GROUP_BY) 
+        {
+            result.group_by_keys = ttl_element->group_by_key_columns;
+            for (auto [name, value] : ttl_element->group_by_aggregations)
+            {
+                auto syntax_result = SyntaxAnalyzer(global_context).analyze(value, new_columns.getAllPhysical(), {}, true);
+                auto expr_analyzer = ExpressionAnalyzer(value, syntax_result, global_context);
+
+                result.group_by_aggregations.emplace_back(name, expr_analyzer.getActions(false));
+                result.group_by_aggregations_res_column.emplace_back(name, value->getColumnName());
+
+                for (const auto descr : expr_analyzer.getAnalyzedData().aggregate_descriptions)
+                    result.aggregate_descriptions.push_back(descr);
+            }
+        }
+        return result;
+    };
+
     if (!new_column_ttls.empty())
     {
         NameSet columns_ttl_forbidden;
@@ -672,7 +703,8 @@ void MergeTreeData::setTTLExpressions(const ColumnsDescription & new_columns,
                     throw Exception("More than one DELETE TTL expression is not allowed", ErrorCodes::BAD_TTL_EXPRESSION);
                 }
 
-                auto new_rows_ttl_entry = create_ttl_entry(ttl_element->children[0]);
+                LOG_DEBUG(log, "ttl_element->size is " << ttl_element->size());
+                auto new_rows_ttl_entry = create_rows_ttl_entry(ttl_element);
                 if (!only_check)
                     update_rows_ttl_entry = new_rows_ttl_entry;
 
@@ -680,7 +712,7 @@ void MergeTreeData::setTTLExpressions(const ColumnsDescription & new_columns,
             }
             else
             {
-                auto new_ttl_entry = create_ttl_entry(ttl_element->children[0]);
+                auto new_ttl_entry = create_rows_ttl_entry(ttl_element);
 
                 new_ttl_entry.entry_ast = ttl_element_ptr;
                 new_ttl_entry.destination_type = ttl_element->destination_type;

src/Storages/MergeTree/MergeTreeData.h

@@ -20,6 +20,7 @@
 #include <Storages/MergeTree/MergeTreePartsMover.h>
 #include <Interpreters/PartLog.h>
 #include <Disks/StoragePolicy.h>
+#include <Interpreters/Aggregator.h>
 
 #include <boost/multi_index_container.hpp>
 #include <boost/multi_index/ordered_index.hpp>
@@ -652,6 +653,14 @@ public:
         ExpressionActionsPtr expression;
         String result_column;
 
+        ExpressionActionsPtr where_expression;
+        String where_filter_column;
+
+        Names group_by_keys;
+        std::vector<std::pair<String, ExpressionActionsPtr>> group_by_aggregations;
+        std::vector<std::pair<String, String>> group_by_aggregations_res_column;
+        AggregateDescriptions aggregate_descriptions;
+
         /// Name and type of a destination are only valid in table-level context.
         PartDestinationType destination_type;
         String destination_name;