Many files:

  Fix Bug #1942: do not retrieve all columns in a table if we only need the 'ref' of the row (usually, the PRIMARY KEY) to calculate an ORDER BY


innobase/dict/dict0dict.c:
  Fix Bug #1942: do not retrieve all columns in a table if we only need the 'ref' of the row (usually, the PRIMARY KEY) to calculate an ORDER BY
innobase/include/dict0dict.h:
  Fix Bug #1942: do not retrieve all columns in a table if we only need the 'ref' of the row (usually, the PRIMARY KEY) to calculate an ORDER BY
innobase/include/row0mysql.h:
  Fix Bug #1942: do not retrieve all columns in a table if we only need the 'ref' of the row (usually, the PRIMARY KEY) to calculate an ORDER BY
sql/ha_innodb.cc:
  Fix Bug #1942: do not retrieve all columns in a table if we only need the 'ref' of the row (usually, the PRIMARY KEY) to calculate an ORDER BY
sql/sql_select.cc:
  Fix Bug #1942: do not retrieve all columns in a table if we only need the 'ref' of the row (usually, the PRIMARY KEY) to calculate an ORDER BY
include/my_base.h:
  Fix Bug #1942: do not retrieve all columns in a table if we only need the 'ref' of the row (usually, the PRIMARY KEY) to calculate an ORDER BY

2 files changed, 25 insertions, 7 deletions

diff --git a/innobase/include/dict0dict.h b/innobase/include/dict0dict.h
index 534c9e380b8..688685cff8b 100644
--- a/innobase/include/dict0dict.h
+++ b/innobase/include/dict0dict.h
@@ -493,6 +493,17 @@ dict_table_get_sys_col_no(
 				/* out: column number */
 	dict_table_t*	table,	/* in: table */
 	ulint		sys);	/* in: DATA_ROW_ID, ... */
+/************************************************************************
+Checks if a column is in the ordering columns of the clustered index of a
+table. Column prefixes are treated like whole columns. */
+
+ibool
+dict_table_col_in_clustered_key(
+/*============================*/
+				/* out: TRUE if the column, or its prefix, is
+				in the clustered key */
+	dict_table_t*	table,	/* in: table */
+	ulint		n);	/* in: column number */
 /***********************************************************************
 Copies types of columns contained in table to tuple. */
 
diff --git a/innobase/include/row0mysql.h b/innobase/include/row0mysql.h
index fade3709631..32a0c8b5d75 100644
--- a/innobase/include/row0mysql.h
+++ b/innobase/include/row0mysql.h
@@ -510,13 +510,15 @@ struct row_prebuilt_struct {
 	byte*		ins_upd_rec_buff;/* buffer for storing data converted
 					to the Innobase format from the MySQL
 					format */
-	ibool		hint_no_need_to_fetch_extra_cols;
-					/* normally this is TRUE, but
-					MySQL will set this to FALSE
-					if we might be required to fetch also
-					other columns than mentioned in the
-					query: the clustered index column(s),
-					or an auto-increment column*/
+	ulint		hint_need_to_fetch_extra_cols;
+					/* normally this is set to 0; if this
+					is set to ROW_RETRIEVE_PRIMARY_KEY,
+					then we should at least retrieve all
+					columns in the primary key; if this
+					is set to ROW_RETRIEVE_ALL_COLS, then
+					we must retrieve all columns in the
+					key (if read_just_key == 1), or all
+					columns in the table */
 	upd_node_t*	upd_node;	/* Innobase SQL update node used
 					to perform updates and deletes */
 	que_fork_t*	ins_graph;	/* Innobase SQL query graph used
@@ -572,6 +574,11 @@ struct row_prebuilt_struct {
 #define ROW_MYSQL_DUMMY_TEMPLATE 3	/* dummy template used in
 					row_scan_and_check_index */
 
+/* Values for hint_need_to_fetch_extra_cols */
+#define ROW_RETRIEVE_PRIMARY_KEY	1
+#define ROW_RETRIEVE_ALL_COLS		2
+
+
 #ifndef UNIV_NONINL
 #include "row0mysql.ic"
 #endif