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MDEV-5414: RAND() in a subselect : different behavior in MariaDB and MySQL

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Materialization forced in case if rand() used in view or derived table to avoud several calls of rand for gting value of a field.

Fixed set variable uncachable flag from - it shouldbe a side effect not a random value.
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unknown
2013-12-18 15:59:51 +02:00
parent 3ec4296ec4
commit 57400ee681
8 changed files with 261 additions and 3 deletions
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8
sql/sql_derived.cc
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@ -357,6 +357,14 @@ bool mysql_derived_merge(THD *thd, LEX *lex, TABLE_LIST *derived)
if (derived->merged)
return FALSE;
if (dt_select->uncacheable & UNCACHEABLE_RAND)
{
/* There is random function => fall back to materialization. */
derived->change_refs_to_fields();
derived->set_materialized_derived();
return FALSE;
}
if (thd->lex->sql_command == SQLCOM_UPDATE_MULTI ||
thd->lex->sql_command == SQLCOM_DELETE_MULTI)
thd->save_prep_leaf_list= TRUE;