better

src/Core/Settings.cpp

@@ -2468,7 +2468,7 @@ Possible values:
 
 - default
 
- This is the equivalent of `hash` or `direct`, if possible (same as `direct,hash`)
+ This is the equivalent of `hash`, `parallel_hash` or `direct`, if possible (same as `direct,parallel_hash,hash`)
 
 - grace_hash
 
@@ -2482,11 +2482,13 @@ Possible values:
 
  [Hash join algorithm](https://en.wikipedia.org/wiki/Hash_join) is used. The most generic implementation that supports all combinations of kind and strictness and multiple join keys that are combined with `OR` in the `JOIN ON` section.
 
+ When using the `hash` algorithm, the right part of `JOIN` is uploaded into RAM.
+
 - parallel_hash
 
  A variation of `hash` join that splits the data into buckets and builds several hashtables instead of one concurrently to speed up this process.
 
- When using the `hash` algorithm, the right part of `JOIN` is uploaded into RAM.
+ When using the `parallel_hash` algorithm, the right part of `JOIN` is uploaded into RAM.
 
 - partial_merge
 

src/Interpreters/TableJoin.cpp

@@ -7,7 +7,9 @@
 
 #include <Core/Block.h>
 #include <Core/ColumnsWithTypeAndName.h>
+#include <Core/Joins.h>
 #include <Core/Settings.h>
+#include <Common/logger_useful.h>
 
 #include <DataTypes/DataTypeNullable.h>
 #include <DataTypes/DataTypeTuple.h>
@@ -28,7 +30,6 @@
 #include <Storages/StorageDictionary.h>
 #include <Storages/StorageJoin.h>
 
-#include <Common/logger_useful.h>
 #include <algorithm>
 #include <string>
 #include <type_traits>
@@ -997,8 +998,8 @@ void TableJoin::resetToCross()
 
 bool TableJoin::allowParallelHashJoin() const
 {
-    if (std::ranges::find(join_algorithm, JoinAlgorithm::DEFAULT) == join_algorithm.end()
+    if (std::ranges::none_of(
-        && std::ranges::find(join_algorithm, JoinAlgorithm::PARALLEL_HASH) == join_algorithm.end())
+            join_algorithm, [](auto algo) { return algo == JoinAlgorithm::DEFAULT || algo == JoinAlgorithm::PARALLEL_HASH; }))
         return false;
     if (!right_storage_name.empty())
         return false;

src/Interpreters/TableJoin.h

@@ -1,25 +1,26 @@
 #pragma once
 
+#include <Core/Joins.h>
 #include <Core/Names.h>
 #include <Core/NamesAndTypes.h>
-#include <Parsers/ASTTablesInSelectQuery.h>
-#include <Interpreters/IJoin.h>
-#include <Interpreters/JoinUtils.h>
-#include <QueryPipeline/SizeLimits.h>
 #include <DataTypes/getLeastSupertype.h>
+#include <Interpreters/IJoin.h>
 #include <Interpreters/IKeyValueEntity.h>
+#include <Interpreters/JoinUtils.h>
 #include <Interpreters/TemporaryDataOnDisk.h>
-
+#include <Parsers/ASTTablesInSelectQuery.h>
-#include <Common/Exception.h>
 #include <Parsers/IAST_fwd.h>
+#include <QueryPipeline/SizeLimits.h>
+#include <Common/Exception.h>
 
-#include <cstddef>
-#include <unordered_map>
-
-#include <utility>
-#include <memory>
 #include <base/types.h>
 
+#include <algorithm>
+#include <cstddef>
+#include <memory>
+#include <unordered_map>
+#include <utility>
+
 namespace CurrentMetrics
 {
     extern const Metric TemporaryFilesForJoin;
@@ -285,10 +286,12 @@ public:
 
     bool isEnabledAlgorithm(JoinAlgorithm val) const
     {
-        /// When join_algorithm = 'default' (not specified by user) we use hash or direct algorithm.
+        /// When join_algorithm = 'default' (not specified by user) we use [parallel_]hash or direct algorithm.
         /// It's behaviour that was initially supported by clickhouse.
         bool is_default_enabled = std::find(join_algorithm.begin(), join_algorithm.end(), JoinAlgorithm::DEFAULT) != join_algorithm.end();
-        if (is_default_enabled && (val == JoinAlgorithm::DEFAULT || val == JoinAlgorithm::HASH || val == JoinAlgorithm::DIRECT))
+        constexpr auto default_algorithms = std::array<JoinAlgorithm, 4>{
+            JoinAlgorithm::DEFAULT, JoinAlgorithm::HASH, JoinAlgorithm::PARALLEL_HASH, JoinAlgorithm::DIRECT};
+        if (is_default_enabled && std::ranges::find(default_algorithms, val) != default_algorithms.end())
             return true;
         return std::find(join_algorithm.begin(), join_algorithm.end(), val) != join_algorithm.end();
     }