Add column primary_key_size to system.parts

docs/en/operations/system-tables/parts.md

@@ -39,6 +39,8 @@ Columns:
 
 - `data_uncompressed_bytes` ([UInt64](../../sql-reference/data-types/int-uint.md)) – Total size of uncompressed data in the data part. All the auxiliary files (for example, files with marks) are not included.
 
+- `primary_key_size` ([UInt64](../../sql-reference/data-types/int-uint.md)) – The amount of memory (in bytes) used by primary key values in the primary.idx/cidx file on disk.
+
 - `marks_bytes` ([UInt64](../../sql-reference/data-types/int-uint.md)) – The size of the file with marks.
 
 - `secondary_indices_compressed_bytes` ([UInt64](../../sql-reference/data-types/int-uint.md)) – Total size of compressed data for secondary indices in the data part. All the auxiliary files (for example, files with marks) are not included.

src/Storages/MergeTree/IMergeTreeDataPart.cpp

@@ -1,5 +1,6 @@
 #include "IMergeTreeDataPart.h"
 #include "Storages/MergeTree/IDataPartStorage.h"
+#include "base/types.h"
 
 #include <optional>
 #include <boost/algorithm/string/join.hpp>
@@ -1803,6 +1804,22 @@ MutableDataPartStoragePtr IMergeTreeDataPart::makeCloneOnDisk(const DiskPtr & di
     return getDataPartStorage().clonePart(path_to_clone, getDataPartStorage().getPartDirectory(), disk, storage.log);
 }
 
+UInt64 IMergeTreeDataPart::getIndexSizeFromFile() const
+{
+    auto metadata_snapshot = storage.getInMemoryMetadataPtr();
+    if (parent_part)
+        metadata_snapshot = metadata_snapshot->projections.get(name).metadata;
+    const auto & pk = metadata_snapshot->getPrimaryKey();
+    if (!pk.column_names.empty())
+    {
+        String file = "primary" + getIndexExtension(false);
+        if (checksums.files.contains("primary" + getIndexExtension(true)))
+            file = "primary" + getIndexExtension(true);
+        return getFileSizeOrZero(file);
+    }
+    return 0;
+}
+
 void IMergeTreeDataPart::checkConsistencyBase() const
 {
     auto metadata_snapshot = storage.getInMemoryMetadataPtr();

src/Storages/MergeTree/IMergeTreeDataPart.h

@@ -346,6 +346,7 @@ class IMergeTreeDataPart : public std::enable_shared_from_this<IMergeTreeDataPar
     UInt64 getIndexSizeInBytes() const;
     UInt64 getIndexSizeInAllocatedBytes() const;
     UInt64 getMarksCount() const;
+    UInt64 getIndexSizeFromFile() const;
 
     UInt64 getBytesOnDisk() const { return bytes_on_disk; }
     void setBytesOnDisk(UInt64 bytes_on_disk_) { bytes_on_disk = bytes_on_disk_; }

src/Storages/System/StorageSystemParts.cpp

@@ -57,6 +57,7 @@ StorageSystemParts::StorageSystemParts(const StorageID & table_id_)
         {"bytes_on_disk",                               std::make_shared<DataTypeUInt64>()},
         {"data_compressed_bytes",                       std::make_shared<DataTypeUInt64>()},
         {"data_uncompressed_bytes",                     std::make_shared<DataTypeUInt64>()},
+        {"primary_key_size",                            std::make_shared<DataTypeUInt64>()},
         {"marks_bytes",                                 std::make_shared<DataTypeUInt64>()},
         {"secondary_indices_compressed_bytes",          std::make_shared<DataTypeUInt64>()},
         {"secondary_indices_uncompressed_bytes",        std::make_shared<DataTypeUInt64>()},
@@ -168,6 +169,8 @@ void StorageSystemParts::processNextStorage(
             columns[res_index++]->insert(columns_size.data_compressed);
         if (columns_mask[src_index++])
             columns[res_index++]->insert(columns_size.data_uncompressed);
+        if (columns_mask[src_index++])
+            columns[res_index++]->insert(part->getIndexSizeFromFile());
         if (columns_mask[src_index++])
             columns[res_index++]->insert(columns_size.marks);
         if (columns_mask[src_index++])

tests/queries/0_stateless/02117_show_create_table_system.reference

@@ -466,6 +466,7 @@ CREATE TABLE system.parts
     `bytes_on_disk` UInt64,
     `data_compressed_bytes` UInt64,
     `data_uncompressed_bytes` UInt64,
+    `primary_key_size` UInt64,
     `marks_bytes` UInt64,
     `secondary_indices_compressed_bytes` UInt64,
     `secondary_indices_uncompressed_bytes` UInt64,