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| author | Evgeny Potemkin <epotemkin@mysql.com> | 2010-02-12 11:51:52 +0300 |
|---|---|---|
| committer | Evgeny Potemkin <epotemkin@mysql.com> | 2010-02-12 11:51:52 +0300 |
| commit | 3e0f70d2cc0d233f0be615532ed3a5254930ad17 (patch) | |
| tree | 7e0ebfd00145b87e6233078f7d11b1e3517fa668 /sql/opt_range.cc | |
| parent | 97afccae53a5fda90311f57d328924d736279414 (diff) | |
| download | mariadb-git-3e0f70d2cc0d233f0be615532ed3a5254930ad17.tar.gz | |
Bug#50539: Wrong result when loose index scan is used for an aggregate
function with distinct.
Loose index scan is used to find MIN/MAX values using appropriate index and
thus allow to avoid grouping. For each found row it updates non-aggregated
fields with values from row with found MIN/MAX value.
Without loose index scan non-aggregated fields are copied by end_send_group
function. With loose index scan there is no need in end_send_group and
end_send is used instead. Non-aggregated fields still need to be copied and
this was wrongly implemented in QUICK_GROUP_MIN_MAX_SELECT::get_next.
WL#3220 added a case when loose index scan can be used with end_send_group to
optimize calculation of aggregate functions with distinct. In this case
the row found by QUICK_GROUP_MIN_MAX_SELECT::get_next might belong to a next
group and copying it will produce wrong result.
Update of non-aggregated fields is moved to the end_send function from
QUICK_GROUP_MIN_MAX_SELECT::get_next.
mysql-test/r/group_min_max.result:
Added a test case for the bug#50539.
mysql-test/t/group_min_max.test:
Added a test case for the bug#50539.
sql/opt_range.cc:
Bug#50539: Wrong result when loose index scan is used for an aggregate
function with distinct.
Update of non-aggregated fields is moved to the end_send function from
QUICK_GROUP_MIN_MAX_SELECT::get_next.
sql/sql_select.cc:
Bug#50539: Wrong result when loose index scan is used for an aggregate
function with distinct.
Update of non-aggregated fields is moved to the end_send function from
QUICK_GROUP_MIN_MAX_SELECT::get_next.
Diffstat (limited to 'sql/opt_range.cc')
| -rw-r--r-- | sql/opt_range.cc | 12 |
1 files changed, 1 insertions, 11 deletions
diff --git a/sql/opt_range.cc b/sql/opt_range.cc index ac5b1f575de..5c64a6a64ee 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -10959,17 +10959,7 @@ int QUICK_GROUP_MIN_MAX_SELECT::get_next() } while ((result == HA_ERR_KEY_NOT_FOUND || result == HA_ERR_END_OF_FILE) && is_last_prefix != 0); - if (result == 0) - { - /* - Partially mimic the behavior of end_select_send. Copy the - field data from Item_field::field into Item_field::result_field - of each non-aggregated field (the group fields, and optionally - other fields in non-ANSI SQL mode). - */ - copy_fields(&join->tmp_table_param); - } - else if (result == HA_ERR_KEY_NOT_FOUND) + if (result == HA_ERR_KEY_NOT_FOUND) result= HA_ERR_END_OF_FILE; DBUG_RETURN(result); |