Commit 2162408b authored by heikki@hundin.mysql.fi's avatar heikki@hundin.mysql.fi
Browse files

btr0cur.c: 

  Backport from 4.0: Fix a major bug in InnoDB query estimator for queries of type SELECT ... WHERE col < x and SELECT ... WHERE col > x; MySQL could pick a table scan though the result set was only a few rows in a big table
parent 29fafced

innobase/btr/btr0cur.c

+8 −4
Original line number Diff line number Diff line
@@ -577,12 +577,12 @@ btr_cur_open_at_index_side( 
			page_cur_set_after_last(page, page_cursor);

		}



		if (height == 0) {

		        if (estimate) {

			btr_cur_add_path_info(cursor, height, root_height);

			        btr_cur_add_path_info(cursor, height,

						      root_height);

		        }



		if (height == 0) {



			break;

		}
@@ -594,6 +594,10 @@ btr_cur_open_at_index_side( 
			page_cur_move_to_prev(page_cursor);

		}



		if (estimate) {

			btr_cur_add_path_info(cursor, height, root_height);

		}



		height--;



		node_ptr = page_cur_get_rec(page_cursor);