From 945a595aa36ccf90f89cf1ca8cddefe47b394dd3 Mon Sep 17 00:00:00 2001 From: Sergey Petrunya Date: Mon, 29 Aug 2011 19:57:41 +0400 Subject: BUG#834534: Assertion `0' failed in replace_where_subcondition with semijoin subquery in HAVING - The problem was that the code that made the check whether the subquery is an AND-part of the WHERE clause didn't work correctly for nested subqueries. In particular, grand-child subquery in HAVING was treated as if it was in the WHERE, which eventually caused an assert when replace_where_subcondition looked for the subquery predicate in the WHERE and couldn't find it there. - The fix: Removed implementation of "thd_marker approach". thd->thd_marker was used to determine the location of subquery predicate: setup_conds() would set accordingly it when making the {where|on_expr}->fix_fields(...) call so that AND-parts of the WHERE/ON clauses can determine they are the AND-parts. Item_cond_or::fix_fields(), Item_func::fix_fields(), Item_subselect::fix_fields (this one was missed), and all other items-that-contain-items had to reset thd->thd_marker before calling fix_fields() for their children items, so that the children can see they are not AND-parts of WHERE/ON. - The "thd_marker approach" required that a lot of code in different locations maintains correct value of thd->thd_marker, so it was replaced with: - The new approach with mark_as_condition_AND_part does not keep context in thd->thd_marker. Instead, setup_conds() now calls {where|on_expr}->mark_as_condition_AND_part() and implementations of that function make sure that: - parts of AND-expressions get the mark_as_condition_AND_part() call - Item_in_subselect objects record that they are AND-parts of WHERE/ON --- sql/sql_class.h | 9 --------- 1 file changed, 9 deletions(-) (limited to 'sql/sql_class.h') diff --git a/sql/sql_class.h b/sql/sql_class.h index c97cc34e166..7cc8cfc5147 100644 --- a/sql/sql_class.h +++ b/sql/sql_class.h @@ -1600,15 +1600,6 @@ public: /* container for handler's private per-connection data */ Ha_data ha_data[MAX_HA]; - /* Place to store various things */ - union - { - /* - Used by subquery optimizations, see Item_in_subselect::emb_on_expr_nest. - */ - TABLE_LIST *emb_on_expr_nest; - } thd_marker; - bool prepare_derived_at_open; /* -- cgit v1.2.1