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BUG#24127: (a,b) IN (SELECT c,d ...) can produce wrong results if a and/or b are NULLs:

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- Make the code produce correct result: use an array of triggers to turn on/off equalities for each
  compared column. Also turn on/off optimizations based on those equalities.
- Make EXPLAIN output show "Full scan on NULL key" for tables for which we switch between
  ref/unique_subquery/index_subquery and ALL access.
- index_subquery engine now has HAVING clause when it is needed, and it is
  displayed in EXPLAIN EXTENDED
- Fix incorrect presense of "Using index" for index/unique-based subqueries (BUG#22930)
// bk trigger note: this commit refers to BUG#24127
This commit is contained in:
sergefp@mysql.com
2007-01-12 23:22:41 +03:00
parent 5236794855
commit c3f46e1f26
14 changed files with 1129 additions and 247 deletions
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2
sql/sql_lex.h
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@@ -469,7 +469,7 @@ public:
void set_thd(THD *thd_arg) { thd= thd_arg; }
friend void lex_start(THD *thd, uchar *buf, uint length);
friend int subselect_union_engine::exec(bool);
friend int subselect_union_engine::exec();
List<Item> *get_unit_column_types();
};