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MDEV-16973 Application-time periods: DELETE

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* inject portion of time updates into mysql_delete main loop
* triggered case emits delete+insert, no updates
* PORTION OF `SYSTEM_TIME` is forbidden
* `DELETE HISTORY .. FOR PORTION OF ...` is forbidden as well
This commit is contained in:
Nikita Malyavin
2019-02-04 09:37:58 +10:00
committed by Sergei Golubchik
parent 073c93b194
commit 47e28a94d5
15 changed files with 1048 additions and 128 deletions
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124
sql/sql_delete.cc
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@ -245,6 +245,50 @@ static bool record_should_be_deleted(THD *thd, TABLE *table, SQL_SELECT *sel,
return false;
}
static
int update_portion_of_time(THD *thd, TABLE *table,
const vers_select_conds_t &period_conds,
bool *inside_period)
{
bool lcond= period_conds.field_start->val_datetime_packed(thd)
< period_conds.start.item->val_datetime_packed(thd);
bool rcond= period_conds.field_end->val_datetime_packed(thd)
> period_conds.end.item->val_datetime_packed(thd);
*inside_period= !lcond && !rcond;
if (*inside_period)
return 0;
DBUG_ASSERT(!table->triggers
|| !table->triggers->has_triggers(TRG_EVENT_INSERT,
TRG_ACTION_BEFORE));
int res= 0;
Item *src= lcond ? period_conds.start.item : period_conds.end.item;
uint dst_fieldno= lcond ? table->s->period.end_fieldno
: table->s->period.start_fieldno;
store_record(table, record[1]);
if (likely(!res))
res= src->save_in_field(table->field[dst_fieldno], true);
if (likely(!res))
res= table->update_generated_fields();
if(likely(!res))
res= table->file->ha_update_row(table->record[1], table->record[0]);
if (likely(!res) && table->triggers)
res= table->triggers->process_triggers(thd, TRG_EVENT_INSERT,
TRG_ACTION_AFTER, true);
restore_record(table, record[1]);
if (likely(!res) && lcond && rcond)
res= table->period_make_insert(period_conds.end.item,
table->field[table->s->period.start_fieldno]);
return res;
}
inline
int TABLE::delete_row()
@ -287,7 +331,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
bool return_error= 0;
ha_rows deleted= 0;
bool reverse= FALSE;
bool has_triggers;
bool has_triggers= false;
ORDER *order= (ORDER *) ((order_list && order_list->elements) ?
order_list->first : NULL);
SELECT_LEX *select_lex= thd->lex->first_select_lex();
@ -298,7 +342,9 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
Explain_delete *explain;
Delete_plan query_plan(thd->mem_root);
Unique * deltempfile= NULL;
bool delete_record, delete_while_scanning;
bool delete_record= false;
bool delete_while_scanning;
bool portion_of_time_through_update;
DBUG_ENTER("mysql_delete");
query_plan.index= MAX_KEY;
@ -313,6 +359,8 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
bool truncate_history= table_list->vers_conditions.is_set();
if (truncate_history)
{
DBUG_ASSERT(!table_list->period_conditions.is_set());
if (table_list->is_view_or_derived())
{
my_error(ER_IT_IS_A_VIEW, MYF(0), table_list->table_name.str);
@ -332,6 +380,18 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
table_list->on_expr= NULL;
}
}
if (table_list->has_period())
{
if (table_list->is_view_or_derived())
{
my_error(ER_IT_IS_A_VIEW, MYF(0), table_list->table_name.str);
DBUG_RETURN(true);
}
conds= select_lex->period_setup_conds(thd, table_list, conds);
if (!conds)
DBUG_RETURN(true);
}
if (mysql_handle_list_of_derived(thd->lex, table_list, DT_MERGE_FOR_INSERT))
DBUG_RETURN(TRUE);
@ -423,12 +483,12 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
- there should be no delete triggers associated with the table.
*/
has_triggers= (table->triggers &&
table->triggers->has_delete_triggers());
has_triggers= table->triggers && table->triggers->has_delete_triggers();
if (!with_select && !using_limit && const_cond_result &&
(!thd->is_current_stmt_binlog_format_row() &&
!has_triggers)
&& !table->versioned(VERS_TIMESTAMP))
&& !table->versioned(VERS_TIMESTAMP) && !table_list->has_period())
{
/* Update the table->file->stats.records number */
table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
@ -598,7 +658,8 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
*/
if ((table->file->ha_table_flags() & HA_CAN_DIRECT_UPDATE_AND_DELETE) &&
!has_triggers && !binlog_is_row && !with_select)
!has_triggers && !binlog_is_row && !with_select &&
!table_list->has_period())
{
table->mark_columns_needed_for_delete();
if (!table->check_virtual_columns_marked_for_read())
@ -668,7 +729,10 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
if (unlikely(init_ftfuncs(thd, select_lex, 1)))
goto got_error;
table->mark_columns_needed_for_delete();
if (table_list->has_period())
table->use_all_columns();
else
table->mark_columns_needed_for_delete();
if ((table->file->ha_table_flags() & HA_CAN_FORCE_BULK_DELETE) &&
!table->prepare_triggers_for_delete_stmt_or_event())
@ -725,6 +789,24 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
delete_record= true;
}
/*
From SQL2016, Part 2, 15.7 <Effect of deleting rows from base table>,
General Rules, 8), we can conclude that DELETE FOR PORTTION OF time performs
0-2 INSERTS + DELETE. We can substitute INSERT+DELETE with one UPDATE, with
a condition of no side effects. The side effect is possible if there is a
BEFORE INSERT trigger, since it is the only one splitting DELETE and INSERT
operations.
Another possible side effect is related to tables of non-transactional
engines, since UPDATE is anyway atomic, and DELETE+INSERT is not.
This optimization is not possible for system-versioned table.
*/
portion_of_time_through_update=
!(table->triggers && table->triggers->has_triggers(TRG_EVENT_INSERT,
TRG_ACTION_BEFORE))
&& !table->versioned()
&& table->file->has_transactions();
THD_STAGE_INFO(thd, stage_updating);
while (likely(!(error=info.read_record())) && likely(!thd->killed) &&
likely(!thd->is_error()))
@ -748,7 +830,23 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
break;
}
error= table->delete_row();
if (table_list->has_period() && portion_of_time_through_update)
{
bool need_delete= true;
error= update_portion_of_time(thd, table, table_list->period_conditions,
&need_delete);
if (likely(!error) && need_delete)
error= table->delete_row();
}
else
{
error= table->delete_row();
if (likely(!error) && table_list->has_period()
&& !portion_of_time_through_update)
error= table->insert_portion_of_time(thd, table_list->period_conditions);
}
if (likely(!error))
{
deleted++;
@ -798,6 +896,8 @@ terminate_delete:
}
THD_STAGE_INFO(thd, stage_end);
end_read_record(&info);
if (table_list->has_period())
table->file->ha_release_auto_increment();
if (options & OPTION_QUICK)
(void) table->file->extra(HA_EXTRA_NORMAL);
ANALYZE_STOP_TRACKING(&explain->command_tracker);
@ -967,7 +1067,13 @@ int mysql_prepare_delete(THD *thd, TABLE_LIST *table_list,
DBUG_RETURN(TRUE);
}
if (unique_table(thd, table_list, table_list->next_global, 0))
/*
Application-time periods: if FOR PORTION OF ... syntax used, DELETE
statement could issue delete_row's mixed with write_row's. This causes
problems for myisam and corrupts table, if deleting while scanning.
*/
if (table_list->has_period()
|| unique_table(thd, table_list, table_list->next_global, 0))
*delete_while_scanning= false;
if (select_lex->inner_refs_list.elements &&