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[SHOW] EXPLAIN UPDATE/DELETE, code re-structuring

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- Make EXPLAIN UPDATE/DELETE use "Query Plan Footprints", too.
This commit is contained in:
Sergey Petrunya
2013-06-18 21:08:34 +04:00
parent 1c6fc3f6b9
commit 1951d40a88
6 changed files with 152 additions and 115 deletions
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152
sql/sql_delete.cc
View File

@ -51,8 +51,7 @@
invoked on a running DELETE statement.
*/
int Delete_plan::print_explain(select_result_sink *output, uint8 explain_flags,
bool *printed_anything)
int Delete_plan::print_explain(select_result_sink *output, uint8 explain_flags)
{
if (deleting_all_rows)
{
@ -62,37 +61,15 @@ int Delete_plan::print_explain(select_result_sink *output, uint8 explain_flags,
{
return 1;
}
*printed_anything= true;
return 0;
}
return Update_plan::print_explain(output, explain_flags, printed_anything);
return Update_plan::print_explain(output, explain_flags);
}
int Update_plan::print_explain(select_result_sink *output, uint8 explain_flags,
bool *printed_anything)
void Update_plan::save_query_plan_footprint()
{
if (impossible_where)
{
const char *msg= "Impossible where";
if (print_explain_message_line(output, explain_flags, 1/*select number*/,
"SIMPLE", msg))
{
return 1;
}
*printed_anything= true;
return 0;
}
select_lex->set_explain_type(TRUE);
select_lex->set_explain_type(FALSE);
/*
Print an EXPLAIN line. We dont have join, so we can't directly use
JOIN::print_explain.
We do have a SELECT_LEX (TODO but how is it useful? it has select_type..
and that's it?)
*/
enum join_type jtype;
if (select && select->quick)
{
int quick_type= select->quick->get_type();
@ -112,35 +89,53 @@ int Update_plan::print_explain(select_result_sink *output, uint8 explain_flags,
jtype= JT_NEXT;
}
StringBuffer<128> possible_keys_line;
using_where= test(select && select->cond);
//using_filesort is already set
make_possible_keys_line(table, possible_keys, &possible_keys_line);
const char *key_name;
const char *key_len;
StringBuffer<128> key_str;
StringBuffer<128> key_len_str;
StringBuffer<128> extra_str;
/* Calculate key_len */
if (select && select->quick)
{
select->quick->add_keys_and_lengths(&key_str, &key_len_str);
key_name= key_str.c_ptr();
key_len= key_len_str.c_ptr();
}
else
{
key_name= (index == MAX_KEY)? NULL : table->key_info[index].name;
key_len= NULL;
if (index != MAX_KEY)
{
key_str.append(table->key_info[index].name);
}
// key_len stays NULL
}
if (select && select->cond)
extra_str.append(STRING_WITH_LEN("Using where"));
if (select && select->quick &&
select->quick->get_type() == QUICK_SELECT_I::QS_TYPE_RANGE)
{
explain_append_mrr_info((QUICK_RANGE_SELECT*)select->quick, &extra_str);
explain_append_mrr_info((QUICK_RANGE_SELECT*)select->quick, &mrr_type);
}
}
int Update_plan::print_explain(select_result_sink *output, uint8 explain_flags)
{
StringBuffer<64> extra_str;
if (impossible_where)
{
const char *msg= "Impossible where";
if (print_explain_message_line(output, explain_flags, 1/*select number*/,
"SIMPLE", msg))
{
return 1;
}
return 0;
}
if (using_where)
extra_str.append(STRING_WITH_LEN("Using where"));
if (mrr_type.length() != 0)
{
if (extra_str.length() !=0)
extra_str.append(STRING_WITH_LEN("; "));
extra_str.append(mrr_type);
}
if (using_filesort)
@ -160,15 +155,14 @@ int Update_plan::print_explain(select_result_sink *output, uint8 explain_flags,
select_lex->type,
table->pos_in_table_list->alias,
// partitions,
jtype,
(enum join_type) jtype,
possible_keys_line.length()? possible_keys_line.c_ptr(): NULL,
key_name,
key_len,
key_str.length()? key_str.c_ptr() : NULL,
key_len_str.length() ? key_len_str.c_ptr() : NULL,
NULL, /* 'ref' is always NULL in single-table EXPLAIN DELETE */
select ? select->records : table_rows,
extra_str.c_ptr());
*printed_anything= true;
/*
psergey-todo: handle all this through saving QPF.
@ -211,10 +205,10 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
SELECT_LEX *select_lex= &thd->lex->select_lex;
killed_state killed_status= NOT_KILLED;
THD::enum_binlog_query_type query_type= THD::ROW_QUERY_TYPE;
Delete_plan query_plan;
query_plan.index= MAX_KEY;
query_plan.using_filesort= FALSE;
Delete_plan *query_plan = new Delete_plan;
query_plan->index= MAX_KEY;
query_plan->using_filesort= FALSE;
DBUG_ENTER("mysql_delete");
if (open_and_lock_tables(thd, table_list, TRUE, 0))
@ -238,8 +232,8 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
}
thd_proc_info(thd, "init");
table->map=1;
query_plan.select_lex= &thd->lex->select_lex;
query_plan.table= table;
query_plan->select_lex= &thd->lex->select_lex;
query_plan->table= table;
if (mysql_prepare_delete(thd, table_list, &conds))
DBUG_RETURN(TRUE);
@ -314,7 +308,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
ha_rows const maybe_deleted= table->file->stats.records;
DBUG_PRINT("debug", ("Trying to use delete_all_rows()"));
query_plan.set_delete_all_rows(maybe_deleted);
query_plan->set_delete_all_rows(maybe_deleted);
if (thd->lex->describe)
goto exit_without_my_ok;
@ -344,7 +338,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
if (result == Item::COND_FALSE) // Impossible where
{
limit= 0;
query_plan.set_impossible_where();
query_plan->set_impossible_where();
if (thd->lex->describe)
goto exit_without_my_ok;
}
@ -372,7 +366,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
DBUG_RETURN(TRUE);
if ((select && select->check_quick(thd, safe_update, limit)) || !limit)
{
query_plan.set_impossible_where();
query_plan->set_impossible_where();
if (thd->lex->describe)
goto exit_without_my_ok;
@ -413,20 +407,22 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
if (select && select->quick && select->quick->unique_key_range())
{ // Single row select (always "ordered")
query_plan.using_filesort= FALSE;
query_plan.index= MAX_KEY;
query_plan->using_filesort= FALSE;
query_plan->index= MAX_KEY;
}
else
query_plan.index= get_index_for_order(order, table, select, limit,
&query_plan.using_filesort,
&reverse);
query_plan->index= get_index_for_order(order, table, select, limit,
&query_plan->using_filesort,
&reverse);
}
query_plan.select= select;
query_plan.possible_keys= table->quick_keys;
query_plan.table_rows= table->file->stats.records;
thd->lex->upd_del_plan= &query_plan;
query_plan->select= select;
query_plan->possible_keys= table->quick_keys;
query_plan->table_rows= table->file->stats.records;
thd->lex->query_plan_footprint= new QPF_query;
thd->lex->query_plan_footprint->upd_del_plan= query_plan;
/*
Ok, we have generated a query plan for the DELETE.
- if we're running EXPLAIN DELETE, goto produce explain output
@ -435,11 +431,12 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
if (thd->lex->describe)
goto exit_without_my_ok;
query_plan->save_query_plan_footprint();
thd->apc_target.enable();
DBUG_EXECUTE_IF("show_explain_probe_delete_exec_start",
dbug_serve_apcs(thd, 1););
if (query_plan.using_filesort)
if (query_plan->using_filesort)
{
ha_rows examined_rows;
ha_rows found_rows;
@ -447,7 +444,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
SORT_FIELD *sortorder;
{
DBUG_ASSERT(query_plan.index == MAX_KEY);
DBUG_ASSERT(query_plan->index == MAX_KEY);
table->sort.io_cache= (IO_CACHE *) my_malloc(sizeof(IO_CACHE),
MYF(MY_FAE | MY_ZEROFILL |
MY_THREAD_SPECIFIC));
@ -483,7 +480,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
thd->apc_target.disable();
DBUG_RETURN(TRUE);
}
if (query_plan.index == MAX_KEY || (select && select->quick))
if (query_plan->index == MAX_KEY || (select && select->quick))
{
if (init_read_record(&info, thd, table, select, 1, 1, FALSE))
{
@ -494,7 +491,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
}
}
else
init_read_record_idx(&info, thd, table, 1, query_plan.index, reverse);
init_read_record_idx(&info, thd, table, 1, query_plan->index, reverse);
init_ftfuncs(thd, select_lex, 1);
thd_proc_info(thd, "updating");
@ -587,6 +584,11 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
(void) table->file->extra(HA_EXTRA_NORMAL);
thd->apc_target.disable();
if (thd->lex->query_plan_footprint)
{
delete thd->lex->query_plan_footprint;
thd->lex->query_plan_footprint= NULL;
}
cleanup:
/*
Invalidate the table in the query cache if something changed. This must
@ -650,21 +652,25 @@ cleanup:
/* Special exits */
exit_without_my_ok:
thd->lex->upd_del_plan= &query_plan;
query_plan->save_query_plan_footprint();
thd->lex->query_plan_footprint->upd_del_plan= query_plan;
select_send *result;
bool printed_anything;
if (!(result= new select_send()))
return 1; /* purecov: inspected */
List<Item> dummy; /* note: looked in 5.6 and they too use a dummy list like this */
result->prepare(dummy, &thd->lex->unit);
thd->send_explain_fields(result);
int err2= thd->lex->print_explain(result, 0 /* explain flags*/, &printed_anything);
int err2= thd->lex->query_plan_footprint->print_explain(result, 0);
if (err2)
result->abort_result_set();
else
result->send_eof();
delete thd->lex->query_plan_footprint;
thd->lex->query_plan_footprint= NULL;
delete select;
free_underlaid_joins(thd, select_lex);