diff options
Diffstat (limited to 'sql/sql_derived.cc')
| -rw-r--r-- | sql/sql_derived.cc | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc index e9928572142..7ad0b4b4c69 100644 --- a/sql/sql_derived.cc +++ b/sql/sql_derived.cc @@ -367,7 +367,11 @@ 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) { @@ -678,6 +682,17 @@ 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 select_union)) @@ -807,6 +822,11 @@ bool mysql_derived_optimize(THD *thd, LEX *lex, TABLE_LIST *derived) DBUG_PRINT("enter", ("Alias: '%s' Unit: %p", (derived->alias ? derived->alias : "<NULL>"), derived->get_unit())); + if (derived->merged) + { + DBUG_PRINT("info", ("Irreversibly merged: exit")); + DBUG_RETURN(FALSE); + } if (unit->optimized) DBUG_RETURN(FALSE); |