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bugfix: multi-UPDATE, vcols, const tables

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multi-update was setting up read_set/vcol_set in
multi_update::initialize_tables() that is invoked after
the optimizer (JOIN::optimize_inner()). But some rows - if they're from
const tables - will be read already in the optimizer, and these rows
will not have all necessary column/vcol values.

* multi_update::initialize_tables() uses results from the optimizer
  and cannot be moved to be called earlier.
* multi_update::prepare() is called before the optimizer, but
  it cannot set up read_set/vcol_set, because the optimizer
  might reset them (see SELECT_LEX::update_used_tables()).

As a fix I've added a new method, select_result::prepare_to_read_rows(),
it's called from inside the optimizer just before make_join_statistics().
This commit is contained in:
Sergei Golubchik
2016-11-23 12:54:59 +01:00
parent 0e401bf7bf
commit aebb1038aa
8 changed files with 63 additions and 17 deletions
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11
sql/sql_delete.cc
View File

@ -924,6 +924,15 @@ multi_delete::prepare(List<Item> &values, SELECT_LEX_UNIT *u)
DBUG_RETURN(0);
}
void multi_delete::prepare_to_read_rows()
{
/* see multi_update::prepare_to_read_rows() */
for (TABLE_LIST *walk= delete_tables; walk; walk= walk->next_local)
{
TABLE_LIST *tbl= walk->correspondent_table->find_table_for_update();
tbl->table->mark_columns_needed_for_delete();
}
}
bool
multi_delete::initialize_tables(JOIN *join)
@ -953,7 +962,6 @@ multi_delete::initialize_tables(JOIN *join)
}
}
walk= delete_tables;
for (JOIN_TAB *tab= first_linear_tab(join, WITHOUT_BUSH_ROOTS,
@ -977,7 +985,6 @@ multi_delete::initialize_tables(JOIN *join)
normal_tables= 1;
tbl->prepare_triggers_for_delete_stmt_or_event();
tbl->prepare_for_position();
tbl->mark_columns_needed_for_delete();
}
else if ((tab->type != JT_SYSTEM && tab->type != JT_CONST) &&
walk == delete_tables)