diff options
Diffstat (limited to 'sql/sql_derived.cc')
| -rw-r--r-- | sql/sql_derived.cc | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc index 12f230724fb..be5058b7c63 100644 --- a/sql/sql_derived.cc +++ b/sql/sql_derived.cc @@ -369,7 +369,11 @@ bool mysql_derived_merge(THD *thd, LEX *lex, TABLE_LIST *derived) derived->get_unit())); if (derived->merged) + { + + DBUG_PRINT("info", ("Irreversibly merged: exit")); DBUG_RETURN(FALSE); + } if (dt_select->uncacheable & UNCACHEABLE_RAND) { @@ -384,7 +388,6 @@ bool mysql_derived_merge(THD *thd, LEX *lex, TABLE_LIST *derived) thd->save_prep_leaf_list= TRUE; arena= thd->activate_stmt_arena_if_needed(&backup); // For easier test - derived->merged= TRUE; if (!derived->merged_for_insert || (derived->is_multitable() && @@ -448,6 +451,7 @@ bool mysql_derived_merge(THD *thd, LEX *lex, TABLE_LIST *derived) if (parent_lex->join) parent_lex->join->table_count+= dt_select->join->table_count - 1; } + derived->merged= TRUE; if (derived->get_unit()->prepared) { Item *expr= derived->on_expr; @@ -744,6 +748,17 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived) } unit->derived= derived; + + /* + Above cascade call of prepare is important for PS protocol, but after it + is called we can check if we really need prepare for this derived + */ + if (derived->merged) + { + DBUG_PRINT("info", ("Irreversibly merged: exit")); + DBUG_RETURN(FALSE); + } + derived->fill_me= FALSE; if (!(derived->derived_result= new (thd->mem_root) select_unit(thd))) @@ -885,6 +900,11 @@ bool mysql_derived_optimize(THD *thd, LEX *lex, TABLE_LIST *derived) DBUG_PRINT("enter", ("Alias: '%s' Unit: %p", (derived->alias.str ? derived->alias.str : "<NULL>"), derived->get_unit())); + if (derived->merged) + { + DBUG_PRINT("info", ("Irreversibly merged: exit")); + DBUG_RETURN(FALSE); + } lex->current_select= first_select; |