diff options
| author | Nayuta Yanagisawa <nayuta.yanagisawa@hey.com> | 2021-07-13 07:53:19 +0000 |
|---|---|---|
| committer | Nayuta Yanagisawa <nayuta.yanagisawa@hey.com> | 2021-07-22 10:05:46 +0000 |
| commit | aafb88865796bf5d3aa8f131aba67adbec3694ce (patch) | |
| tree | e82da6456508f14c699f7c1c2f6c6b626e0df729 /include/mysql/service_json.h | |
| parent | 7ffa801cf2a7d0a4e55b84908dede6493c7ae73d (diff) | |
| download | mariadb-git-aafb88865796bf5d3aa8f131aba67adbec3694ce.tar.gz | |
MDEV-26013 distinct not work properly in some cases for spider tables
The bug is caused by the following reasons:
* spider_group_by_handler::init_scan() generates a query for a data node.
* The function adds DISTINCT if and only if
spider_group_by_handler::query::distinct is TRUE.
* spider_group_by_handler::query::distinct is set to the value of
JOIN::select_distinct in JOIN::make_aggr_tables_info().
* In the test case, DISTINCT is not added because JOIN::select_distinct
is FALSE at the call of JOIN::make_aggr_tables_info().
Why JOIN::select_distinct is set to FALSE? That is because the function
JOIN::optimize_stage2() convert DISTINCT into GROUP BY and then optimizes
away GROUP BY.
Diffstat (limited to 'include/mysql/service_json.h')
0 files changed, 0 insertions, 0 deletions