Follow @dyemanov suggestions.

src/jrd/sort.cpp

@@ -2195,7 +2195,7 @@ void SortOwner::unlinkAll()
 
 	if (buffers.hasData())
 	{
-		// Here we cache blocks to be reused later
+		// Move cached buffers to the database level cache to be reused later by other attachments
 
 		const size_t MAX_CACHED_SORT_BUFFERS = 8; // 1MB
 

src/jrd/sort.h

@@ -431,7 +431,7 @@ public:
 
 private:
 	MemoryPool& pool;
-	Database* dbb;
+	Database* const dbb;
 	Firebird::SortedArray<Sort*> sorts;
 	Firebird::HalfStaticArray<UCHAR*, 4> buffers;
 };