Sergei Golubchik d53eb85997 MDEV-12580 Wrong query result in join when using an index (Version > "10.2.3") ...

JOIN_TAB::remove_redundant_bnl_scan_conds() removes select_cond
from a JOIN_TAB if join cache is enabled, and tab->cache_select->cond
is the equal to tab->select_cond.

But after 8d99166c69 the code to initialize join cache was moved
to happen much later than JOIN_TAB::remove_redundant_bnl_scan_conds(),
and that code might, under certain conditions, revert to *not* using
join cache (set_join_cache_denial()).

If JOIN_TAB::remove_redundant_bnl_scan_conds() removes the WHERE
condition from the JOIN_TAB and later set_join_cache_denial() disables
join cache, we end up with no WHERE condition at all.

Fix: move JOIN_TAB::remove_redundant_bnl_scan_conds() to happen
after all possible set_join_cache_denial() calls.

2017-05-08 11:08:18 +02:00

136 KiB

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