From 409aba3d997e97287bc67467ef437164c9e70b96 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Vicen=C8=9Biu=20Ciorbaru?= Date: Thu, 16 Jan 2020 12:40:45 +0200 Subject: [PATCH] Improve documentation of Unique class * size represents the size of an element in the Unique class * full_size is used when the Unique class counts the number of duplicates stored per element. This requires additional space per Unique element. --- sql/sql_class.h | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/sql/sql_class.h b/sql/sql_class.h index 4a390545593..2fac8d4e87f 100644 --- a/sql/sql_class.h +++ b/sql/sql_class.h @@ -3923,16 +3923,21 @@ class user_var_entry 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 */ ulonglong max_in_memory_size; IO_CACHE file; TREE tree; uchar *record_pointers; + /* Number of elements filtered out due to min_dupl_count when storing results + to table. See Unique::get */ ulong filtered_out_elems; bool flush(); - uint size; - uint full_size; - uint min_dupl_count; /* always 0 for unions, > 0 for intersections */ + uint size; /* Size of element stored in unique object. */ + 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 merge(TABLE *table, uchar *buff, bool without_last_merge);