Add ALTER TABLE UNFREEZE command.

src/Access/AccessType.h

@@ -63,7 +63,7 @@ enum class AccessType
     M(ALTER_SETTINGS, "ALTER SETTING, ALTER MODIFY SETTING, MODIFY SETTING", TABLE, ALTER_TABLE) /* allows to execute ALTER MODIFY SETTING */\
     M(ALTER_MOVE_PARTITION, "ALTER MOVE PART, MOVE PARTITION, MOVE PART", TABLE, ALTER_TABLE) \
     M(ALTER_FETCH_PARTITION, "FETCH PARTITION", TABLE, ALTER_TABLE) \
-    M(ALTER_FREEZE_PARTITION, "FREEZE PARTITION", TABLE, ALTER_TABLE) \
+    M(ALTER_FREEZE_PARTITION, "FREEZE PARTITION, UNFREEZE", TABLE, ALTER_TABLE) \
     \
     M(ALTER_TABLE, "", GROUP, ALTER) \
     \

src/Interpreters/InterpreterAlterQuery.cpp

@@ -298,7 +298,8 @@ AccessRightsElements InterpreterAlterQuery::getRequiredAccessForCommand(const AS
             break;
         }
         case ASTAlterCommand::FREEZE_PARTITION: [[fallthrough]];
-        case ASTAlterCommand::FREEZE_ALL:
+        case ASTAlterCommand::FREEZE_ALL: [[fallthrough]];
+        case ASTAlterCommand::UNFREEZE:
         {
             required_access.emplace_back(AccessType::ALTER_FREEZE_PARTITION, database, table);
             break;

src/Parsers/ASTAlterQuery.cpp

@@ -271,6 +271,15 @@ void ASTAlterCommand::formatImpl(
                           << " " << DB::quote << with_name;
         }
     }
+    else if (type == ASTAlterCommand::UNFREEZE)
+    {
+        settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << "UNFREEZE";
+
+        if (!with_name.empty())
+        {
+            settings.ostr << " " << DB::quote << with_name;
+        }
+    }
     else if (type == ASTAlterCommand::DELETE)
     {
         settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << "DELETE" << (settings.hilite ? hilite_none : "");
@@ -368,7 +377,8 @@ bool ASTAlterQuery::isSettingsAlter() const
 
 bool ASTAlterQuery::isFreezeAlter() const
 {
-    return isOneCommandTypeOnly(ASTAlterCommand::FREEZE_PARTITION) || isOneCommandTypeOnly(ASTAlterCommand::FREEZE_ALL);
+    return isOneCommandTypeOnly(ASTAlterCommand::FREEZE_PARTITION) || isOneCommandTypeOnly(ASTAlterCommand::FREEZE_ALL)
+        || isOneCommandTypeOnly(ASTAlterCommand::UNFREEZE);
 }
 
 /** Get the text that identifies this element. */

src/Parsers/ASTAlterQuery.h

@@ -54,6 +54,7 @@ public:
         FETCH_PARTITION,
         FREEZE_PARTITION,
         FREEZE_ALL,
+        UNFREEZE,
 
         DELETE,
         UPDATE,
@@ -153,7 +154,9 @@ public:
      */
     String from;
 
-    /** For FREEZE PARTITION - place local backup to directory with specified name.
+    /**
+     * For FREEZE PARTITION - place local backup to directory with specified name.
+     * For UNFREEZE - delete local backup at directory with specified name.
      */
     String with_name;
 

src/Parsers/New/AST/AlterTableQuery.h

@@ -137,6 +137,7 @@ class AlterTableClause : public INode
             DROP_INDEX,
             DROP_PARTITION,
             FREEZE_PARTITION,
+            UNFREEZE,
             MODIFY,
             MOVE_PARTITION_TO_DISK,
             MOVE_PARTITION_TO_TABLE,

src/Parsers/ParserAlterQuery.cpp

@@ -63,6 +63,7 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
     ParserKeyword s_fetch_partition("FETCH PARTITION");
     ParserKeyword s_replace_partition("REPLACE PARTITION");
     ParserKeyword s_freeze("FREEZE");
+    ParserKeyword s_unfreeze("UNFREEZE");
     ParserKeyword s_partition("PARTITION");
 
     ParserKeyword s_first("FIRST");
@@ -454,6 +455,16 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
                 command->with_name = ast_with_name->as<ASTLiteral &>().value.get<const String &>();
             }
         }
+        else if (s_unfreeze.ignore(pos, expected))
+        {
+            command->type = ASTAlterCommand::UNFREEZE;
+
+            ASTPtr ast_with_name;
+            if (!parser_string_literal.parse(pos, ast_with_name, expected))
+                return false;
+
+            command->with_name = ast_with_name->as<ASTLiteral &>().value.get<const String &>();
+        }
         else if (s_modify_column.ignore(pos, expected))
         {
             if (s_if_exists.ignore(pos, expected))

src/Storages/MergeTree/MergeTreeData.cpp

@@ -2920,6 +2920,14 @@ Pipe MergeTreeData::alterPartition(
                 current_command_results = freezeAll(command.with_name, metadata_snapshot, query_context, lock);
             }
             break;
+
+            case PartitionCommand::UNFREEZE_PARTITIONS:
+            {
+                auto lock = lockForShare(query_context.getCurrentQueryId(), query_context.getSettingsRef().lock_acquire_timeout);
+                current_command_results = unfreeze(command.with_name, query_context, lock);
+            }
+
+            break;
         }
         for (auto & command_result : current_command_results)
             command_result.command_type = command.typeToString();
@@ -3727,6 +3735,23 @@ PartitionCommandsResultInfo MergeTreeData::freezePartitionsByMatcher(MatcherFn m
     return result;
 }
 
+PartitionCommandsResultInfo MergeTreeData::unfreeze(
+    const String & backup_name,
+    const Context & context,
+    TableLockHolder & ) const
+{
+    String clickhouse_path = Poco::Path(context.getPath()).makeAbsolute().toString();
+    String backup_path = clickhouse_path + "shadow/" + backup_name + "/" + relative_data_path;
+
+    PartitionCommandsResultInfo result;
+
+    for (const auto & disk : getStoragePolicy()->getDisks())
+        if (disk->exists(backup_path))
+            disk->removeRecursive(backup_path);
+
+    return result;
+}
+
 bool MergeTreeData::canReplacePartition(const DataPartPtr & src_part) const
 {
     const auto settings = getSettings();

src/Storages/MergeTree/MergeTreeData.h

@@ -553,6 +553,10 @@ public:
       */
     PartitionCommandsResultInfo freezePartition(const ASTPtr & partition, const StorageMetadataPtr & metadata_snapshot, const String & with_name, const Context & context, TableLockHolder & table_lock_holder);
 
+    PartitionCommandsResultInfo unfreeze(
+        const String & backup_name,
+        const Context & context,
+        TableLockHolder & table_lock_holder) const;
 
 public:
     /// Moves partition to specified Disk

src/Storages/PartitionCommands.cpp

@@ -99,6 +99,13 @@ std::optional<PartitionCommand> PartitionCommand::parse(const ASTAlterCommand *
         command.with_name = command_ast->with_name;
         return command;
     }
+    else if (command_ast->type == ASTAlterCommand::UNFREEZE)
+    {
+        PartitionCommand command;
+        command.type = PartitionCommand::UNFREEZE_PARTITIONS;
+        command.with_name = command_ast->with_name;
+        return command;
+    }
     else
         return {};
 }
@@ -130,6 +137,8 @@ std::string PartitionCommand::typeToString() const
         return "FREEZE ALL";
     case PartitionCommand::Type::FREEZE_PARTITION:
         return "FREEZE PARTITION";
+    case PartitionCommand::Type::UNFREEZE_PARTITIONS:
+        return "UNFREEZE";
     case PartitionCommand::Type::REPLACE_PARTITION:
         return "REPLACE PARTITION";
     }

src/Storages/PartitionCommands.h

@@ -27,6 +27,7 @@ struct PartitionCommand
         FETCH_PARTITION,
         FREEZE_ALL_PARTITIONS,
         FREEZE_PARTITION,
+        UNFREEZE_PARTITIONS,
         REPLACE_PARTITION,
     };
 
@@ -52,7 +53,7 @@ struct PartitionCommand
     /// For FETCH PARTITION - path in ZK to the shard, from which to download the partition.
     String from_zookeeper_path;
 
-    /// For FREEZE PARTITION
+    /// For FREEZE PARTITION and UNFREEZE
     String with_name;
 
     enum MoveDestinationType

tests/integration/test_merge_tree_s3/test.py

@@ -333,3 +333,26 @@ def test_move_replace_partition_to_another_table(cluster):
 
     for obj in list(minio.list_objects(cluster.minio_bucket, 'data/')):
         minio.remove_object(cluster.minio_bucket, obj.object_name)
+
+
+def test_freeze_unfreeze(cluster):
+    create_table(cluster, "s3_test")
+
+    node = cluster.instances["node"]
+    minio = cluster.minio_client
+
+    node.query("INSERT INTO s3_test VALUES {}".format(generate_values('2020-01-03', 4096)))
+    assert len(
+        list(minio.list_objects(cluster.minio_bucket, 'data/'))) == FILES_OVERHEAD + FILES_OVERHEAD_PER_PART_WIDE
+
+    node.query("ALTER TABLE s3_test FREEZE WITH NAME 'backup1'")
+    assert len(
+        list(minio.list_objects(cluster.minio_bucket, 'data/'))) == FILES_OVERHEAD + FILES_OVERHEAD_PER_PART_WIDE
+
+    node.query("TRUNCATE TABLE s3_test")
+    assert len(
+        list(minio.list_objects(cluster.minio_bucket, 'data/'))) == FILES_OVERHEAD + FILES_OVERHEAD_PER_PART_WIDE
+
+    node.query("ALTER TABLE s3_test UNFREEZE 'backup1'")
+    assert len(
+        list(minio.list_objects(cluster.minio_bucket, 'data/'))) == FILES_OVERHEAD