From e74bf0798297551bc02e6d8cac76e0d13ffdad0e Mon Sep 17 00:00:00 2001 From: Sergei Petrunia Date: Thu, 25 Sep 2014 14:29:14 +0400 Subject: [PATCH] Better comments --- sql/sql_select.cc | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/sql/sql_select.cc b/sql/sql_select.cc index e7424b4a318..8a7cb9cdafa 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -25224,15 +25224,18 @@ uint get_index_for_order(ORDER *order, TABLE *table, SQL_SELECT *select, return MAX_KEY; } + /* - Count how much times conditions are true for several first rows of the table + Count how many times the specified conditions are true for first rows_to_read + rows of the table. - @param thd thread handle - @param rows_to_read how much rows to check - @param table table which should be checked - @conds conds list of conditions and countars for them + @param thd Thread handle + @param rows_to_read How many rows to sample + @param table Table to use + @conds conds INOUT List of conditions and counters for them - @return number of really checked rows or 0 in case of error or empty table + @return Number of we've checked. It can be equal or less than rows_to_read. + 0 is returned for error or when the table had no rows. */ ulong check_selectivity(THD *thd,