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MDEV-13784: query causes seg fault

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When we have a nested subquery then a subquery that was a dependent subquery
may change to an independent one when we optimizer the inner subqueries.
This is handled st_select_lex::optimize_unflattened_subqueries.
Currently a subquery that was changed to independent from dependent after optimization
phase incorrectly shows dependent in the output of Explain, this happens because we
don't update used_tables for the WHERE clause, ON clause, etc after the optimization phase.
This commit is contained in:
Varun Gupta
2019-01-06 23:15:25 +05:30
parent b87eb04f77
commit d0d0f88f2c
5 changed files with 78 additions and 4 deletions
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sql/sql_lex.cc
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@ -3551,6 +3551,7 @@ bool st_select_lex::optimize_unflattened_subqueries(bool const_only)
inner_join->select_options|= SELECT_DESCRIBE;
}
res= inner_join->optimize();
sl->update_used_tables();
sl->update_correlated_cache();
is_correlated_unit|= sl->is_correlated;
inner_join->select_options= save_options;