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| author | Igor Babaev <igor@askmonty.org> | 2014-10-14 09:36:50 -0700 |
|---|---|---|
| committer | Igor Babaev <igor@askmonty.org> | 2014-10-14 09:36:50 -0700 |
| commit | 3c4bb0e8720b84a14fe4822d1986d01290b9ab44 (patch) | |
| tree | e474ca9e76d09e770c4e3d5c37e3161d1cc42ace /sql/sql_explain.cc | |
| parent | fec5ab5a56cb9a45c621207620cc85079cddf537 (diff) | |
| download | mariadb-git-3c4bb0e8720b84a14fe4822d1986d01290b9ab44.tar.gz | |
MDEV-334: Backport of UNION ALL optimization from mysql-5.7.
Although the original code of mysql-5.7 was adjusted
to the current MariaDB code the main ideas of the optimization
were preserved.
Diffstat (limited to 'sql/sql_explain.cc')
| -rw-r--r-- | sql/sql_explain.cc | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/sql/sql_explain.cc b/sql/sql_explain.cc index 53ac095d1d0..7ab6413bfef 100644 --- a/sql/sql_explain.cc +++ b/sql/sql_explain.cc @@ -229,6 +229,9 @@ int Explain_union::print_explain(Explain_query *query, sel->print_explain(query, output, explain_flags, is_analyze); } + if (!using_tmp) + return 0; + /* Print a line with "UNION RESULT" */ List<Item> item_list; Item *item_null= new Item_null(); |