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Merge 10.4 into 10.5

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This commit is contained in:
Marko Mäkelä
2020-08-10 21:38:55 +03:00
parent 17be2b47ba eae968f62d
commit 1c58748196
64 changed files with 1622 additions and 466 deletions
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22
sql/sql_union.cc
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@ -1,5 +1,5 @@
/* Copyright (c) 2000, 2017, Oracle and/or its affiliates.
Copyright (c) 2010, 2017, Corporation
Copyright (c) 2010, 2020, MariaDB Corporation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@ -1364,6 +1364,25 @@ bool st_select_lex_unit::prepare(TABLE_LIST *derived_arg,
found_rows_for_union= first_sl->options & OPTION_FOUND_ROWS;
is_union_select= is_unit_op() || fake_select_lex || single_tvc;
/*
If we are reading UNION output and the UNION is in the
IN/ANY/ALL/EXISTS subquery, then ORDER BY is redundant and hence should
be removed.
Example:
select ... col IN (select col2 FROM t1 union select col3 from t2 ORDER BY 1)
(as for ORDER BY ... LIMIT, it currently not supported inside
IN/ALL/ANY subqueries)
(For non-UNION this removal of ORDER BY clause is done in
check_and_do_in_subquery_rewrites())
*/
if (item && is_unit_op() &&
(item->is_in_predicate() || item->is_exists_predicate()))
{
global_parameters()->order_list.first= NULL;
global_parameters()->order_list.elements= 0;
}
/* will only optimize once */
if (!bag_set_op_optimized && !is_recursive)
{
@ -1390,6 +1409,7 @@ bool st_select_lex_unit::prepare(TABLE_LIST *derived_arg,
break;
}
}
/* Global option */
if (is_union_select || is_recursive)