Gleb Shchepa fc827ae387 Fixed bug #36632: SELECT DISTINCT from a simple view on an ...

InnoDB table, where all selected columns
                  belong to the same unique index key, returns
                  incorrect results

Server executes some queries via QUICK_GROUP_MIN_MAX_SELECT
(MIN/MAX optimization for queries with GROUP BY or DISTINCT
clause) and that optimization implies loose index scan, so all
grouping is done by the QUICK_GROUP_MIN_MAX_SELECT::get_next
method.

The server does not set the precomputed_group_by flag for some
QUICK_GROUP_MIN_MAX_SELECT queries and duplicates grouping by
call to the end_send_group function.

Fix: when the test_if_skip_sort_order function selects loose 
index scan as a best way to satisfy an ORDER BY/GROUP BY type
of query, the precomputed_group_by flag has been set to use 
end_send/end_write functions instead of end_send_group/
end_write_group functions.

2008-06-27 23:50:53 +05:00

5.4 KiB

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