1 files changed, 9 insertions, 3 deletions
diff --git a/sql/uniques.h b/sql/uniques.h
index f83eac36855..663d5c1682a 100644
--- a/sql/uniques.h
+++ b/sql/uniques.h
@@ -29,14 +29,20 @@
 class Unique :public Sql_alloc
 {
   DYNAMIC_ARRAY file_ptrs;
-  ulong max_elements;
+  ulong max_elements;   /* Total number of elements that will be stored in-memory */
   size_t max_in_memory_size;
   IO_CACHE file;
   TREE tree;
+ /* Number of elements filtered out due to min_dupl_count when storing results
+    to table. See Unique::get */
   ulong filtered_out_elems;
   uint size;
-  uint full_size;
-  uint min_dupl_count;   /* always 0 for unions, > 0 for intersections */
+
+  uint full_size;   /* Size of element + space needed to store the number of
+                       duplicates found for the element. */
+  uint min_dupl_count;   /* Minimum number of occurences of element required for
+                            it to be written to record_pointers.
+                            always 0 for unions, > 0 for intersections */
   bool with_counters;
 
   bool merge(TABLE *table, uchar *buff, size_t size, bool without_last_merge);