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Code cleanups and add some caching of functions to speed up things

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Detailed description:
- Added more function comments and fixed types in some old comments
- Removed an outdated comment
- Cleaned up some functions in records.cc
  - Replaced "while" with "if"
  - Reused error code
  - Made functions similar
- Added caching of pfs_batch_update()
- Simplified some rowid_filter code
  - Only call build_range_rowid_filter() if rowid filter will be used
  - Replaced tab->is_rowid_filter_built with need_to_build_rowid_filter.
    We only have to test need_to_build_rowid_filter to know if we have
    to build the filter. Old code needed two tests
  - Added function 'clear_range_rowid_filter' to disable rowid filter.
    Made things simpler as we can now clear all rowid filter variables
    in one place.
- Removed some 'if' in sub_select()
This commit is contained in:
Monty 2023-01-10 15:37:28 +02:00
parent 65da564530
commit 3316a54db3
4 changed files with 164 additions and 100 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
sql/records.cc
View File

@ -400,11 +400,8 @@ static int rr_handle_error(READ_RECORD *info, int error)
static int rr_quick(READ_RECORD *info)
{
int tmp;
while ((tmp= info->select->quick->get_next()))
{
if ((tmp= info->select->quick->get_next()))
tmp= rr_handle_error(info, tmp);
break;
}
return tmp;
}
@ -427,16 +424,14 @@ static int rr_index_first(READ_RECORD *info)
int tmp;
// tell handler that we are doing an index scan
if ((tmp = info->table->file->prepare_index_scan()))
{
tmp= rr_handle_error(info, tmp);
return tmp;
}
goto err;
tmp= info->table->file->ha_index_first(info->record());
info->read_record_func= rr_index;
if (tmp)
tmp= rr_handle_error(info, tmp);
return tmp;
if (!(tmp= info->table->file->ha_index_first(info->record())))
return tmp;
err:
return rr_handle_error(info, tmp);
}
@ -455,9 +450,9 @@ static int rr_index_first(READ_RECORD *info)
static int rr_index_last(READ_RECORD *info)
{
int tmp= info->table->file->ha_index_last(info->record());
int tmp;
info->read_record_func= rr_index_desc;
if (tmp)
if ((tmp= info->table->file->ha_index_last(info->record())))
tmp= rr_handle_error(info, tmp);
return tmp;
}

9
sql/sql_join_cache.cc
View File

@ -2146,12 +2146,12 @@ enum_nested_loop_state JOIN_CACHE::join_records(bool skip_last)
if (!join_tab->first_unmatched)
{
bool pfs_batch_update= join_tab->pfs_batch_update(join);
if (pfs_batch_update)
DBUG_ASSERT(join_tab->cached_pfs_batch_update == join_tab->pfs_batch_update());
if (join_tab->cached_pfs_batch_update)
join_tab->table->file->start_psi_batch_mode();
/* Find all records from join_tab that match records from join buffer */
rc= join_matching_records(skip_last);
if (pfs_batch_update)
if (join_tab->cached_pfs_batch_update)
join_tab->table->file->end_psi_batch_mode();
if (rc != NESTED_LOOP_OK && rc != NESTED_LOOP_NO_MORE_ROWS)
goto finish;
@ -2321,7 +2321,8 @@ enum_nested_loop_state JOIN_CACHE::join_matching_records(bool skip_last)
if ((rc= join_tab_execution_startup(join_tab)) < 0)
goto finish2;
join_tab->build_range_rowid_filter_if_needed();
if (join_tab->need_to_build_rowid_filter)
join_tab->build_range_rowid_filter();
/* Prepare to retrieve all records of the joined table */
if (unlikely((error= join_tab_scan->open())))

221
sql/sql_select.cc
View File

@ -1993,7 +1993,10 @@ bool JOIN::make_range_rowid_filters()
tab->range_rowid_filter_info,
filter_container, sel);
if (tab->rowid_filter)
{
tab->need_to_build_rowid_filter= true;
continue;
}
}
no_filter:
if (sel->quick)
@ -2028,16 +2031,16 @@ JOIN::init_range_rowid_filters()
tab;
tab= next_linear_tab(this, tab, WITH_BUSH_ROOTS))
{
tab->need_to_build_rowid_filter= false; // Safety
if (!tab->rowid_filter)
continue;
if (tab->rowid_filter->get_container()->alloc())
{
delete tab->rowid_filter;
tab->rowid_filter= 0;
tab->clear_range_rowid_filter();
continue;
}
tab->table->file->rowid_filter_push(tab->rowid_filter);
tab->is_rowid_filter_built= false;
tab->need_to_build_rowid_filter= true;
}
DBUG_RETURN(0);
}
@ -13331,10 +13334,7 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
sel->quick_keys.clear_all();
sel->needed_reg.clear_all();
if (is_hj && tab->rowid_filter)
{
delete tab->rowid_filter;
tab->rowid_filter= 0;
}
tab->clear_range_rowid_filter();
}
else
{
@ -14021,6 +14021,7 @@ void set_join_cache_denial(JOIN_TAB *join_tab)
don't do join buffering for the first table in sjm nest.
*/
join_tab[-1].next_select= sub_select;
join_tab[-1].cached_pfs_batch_update= join_tab[-1].pfs_batch_update();
if (join_tab->type == JT_REF && join_tab->is_ref_for_hash_join())
{
join_tab->type= JT_ALL;
@ -14850,9 +14851,7 @@ make_join_readinfo(JOIN *join, ulonglong options, uint no_jbuf_after)
*/
if (!(tab->bush_root_tab &&
tab->bush_root_tab->bush_children->end == tab + 1))
{
tab->next_select=sub_select; /* normal select */
}
tab->next_select= sub_select; /* normal select */
if (tab->loosescan_match_tab)
{
@ -15011,6 +15010,7 @@ make_join_readinfo(JOIN *join, ulonglong options, uint no_jbuf_after)
abort();
/* purecov: end */
}
tab->cached_pfs_batch_update= tab->pfs_batch_update();
DBUG_EXECUTE("where",
char buff[256];
@ -15113,37 +15113,58 @@ bool error_if_full_join(JOIN *join)
}
void JOIN_TAB::build_range_rowid_filter_if_needed()
{
if (rowid_filter && !is_rowid_filter_built)
{
/**
The same handler object (table->file) is used to build a filter
and to perfom a primary table access (by the main query).
/**
build_range_rowid_filter()
To estimate the time for filter building tracker should be changed
and after building of the filter has been finished it should be
switched back to the previos tracker.
*/
Exec_time_tracker *table_tracker= table->file->get_time_tracker();
Rowid_filter_tracker *rowid_tracker= rowid_filter->get_tracker();
table->file->set_time_tracker(rowid_tracker->get_time_tracker());
rowid_tracker->start_tracking(join->thd);
if (!rowid_filter->build())
{
is_rowid_filter_built= true;
}
else
{
delete rowid_filter;
rowid_filter= 0;
}
rowid_tracker->stop_tracking(join->thd);
table->file->set_time_tracker(table_tracker);
Build range rowid filter. This function should only be called if
need_to_build_rowid_filter
is true
*/
void JOIN_TAB::build_range_rowid_filter()
{
DBUG_ASSERT(need_to_build_rowid_filter && rowid_filter);
/**
The same handler object (table->file) is used to build a filter
and to perfom a primary table access (by the main query).
To estimate the time for filter building tracker should be changed
and after building of the filter has been finished it should be
switched back to the previos tracker.
*/
Exec_time_tracker *table_tracker= table->file->get_time_tracker();
Rowid_filter_tracker *rowid_tracker= rowid_filter->get_tracker();
table->file->set_time_tracker(rowid_tracker->get_time_tracker());
rowid_tracker->start_tracking(join->thd);
if (rowid_filter->build())
{
/* Failed building rowid filter */
clear_range_rowid_filter();
}
need_to_build_rowid_filter= false;
rowid_tracker->stop_tracking(join->thd);
table->file->set_time_tracker(table_tracker);
}
/*
Clear used rowid filter
Note that rowid_filter is allocated on mem_root and not really freed!
Only the rowid data is freed.
*/
void JOIN_TAB::clear_range_rowid_filter()
{
delete rowid_filter;
rowid_filter= 0;
need_to_build_rowid_filter= false;
range_rowid_filter_info= 0;
}
/**
cleanup JOIN_TAB.
@ -15164,10 +15185,7 @@ void JOIN_TAB::cleanup()
delete quick;
quick= 0;
if (rowid_filter)
{
delete rowid_filter;
rowid_filter= 0;
}
clear_range_rowid_filter();
if (cache)
{
cache->free();
@ -15365,6 +15383,7 @@ double JOIN_TAB::get_examined_rows()
TODO: consider moving this together with join_tab_execution_startup
*/
bool JOIN_TAB::preread_init()
{
TABLE_LIST *derived= table->pos_in_table_list;
@ -15406,7 +15425,31 @@ bool JOIN_TAB::preread_init()
}
bool JOIN_TAB::pfs_batch_update(JOIN *join)
/**
pfs_batch_update()
Check if the used table will do a lot of read calls in a row without
any intervening read calls to any other tables.
@return 0 No
@return 1 Yes
If yes, then the handler will be informed about this with the
start_psi_batch_mode() / end_psi_batch_mode() calls
This is currently used only to speed up performance schema code for
multiple reads.
In the future we may also inform the engine about this. The engine
could use this information to cache the used pages, keep blocks
locked in the page cache and similar things to speed up repeated
reads.
The return value of this function is cached in
JOIN_TAB::cached_pfs_batch_update
*/
bool JOIN_TAB::pfs_batch_update()
{
/*
Use PFS batch mode if
@ -19289,7 +19332,7 @@ bool cond_is_datetime_is_null(Item *cond)
=> SELECT * FROM t1 WHERE ((FALSE AND (a = 5)) OR
((b = 5) AND (a = 5))) AND
(b = 5) AND (a = 5)
After this an additional call of remove_eq_conds() converts it to
After this an additional call of remove_eq_conds() converts it to
=> SELECT * FROM t1 WHERE (b = 5) AND (a = 5)
*/
@ -19402,7 +19445,7 @@ Item_cond::remove_eq_conds(THD *thd, Item::cond_result *cond_value,
else
{
if (new_item->type() == Item::COND_ITEM &&
((Item_cond*) new_item)->functype() == functype())
((Item_cond*) new_item)->functype() == functype())
{
List<Item> *new_item_arg_list=
((Item_cond *) new_item)->argument_list();
@ -22120,6 +22163,7 @@ do_select(JOIN *join, Procedure *procedure)
{
int rc= 0;
enum_nested_loop_state error= NESTED_LOOP_OK;
uint top_level_tables= join->exec_join_tab_cnt();
DBUG_ENTER("do_select");
if (join->pushdown_query)
@ -22136,8 +22180,9 @@ do_select(JOIN *join, Procedure *procedure)
if (join->pushdown_query->store_data_in_temp_table)
{
JOIN_TAB *last_tab= join->join_tab + join->exec_join_tab_cnt();
JOIN_TAB *last_tab= join->join_tab + top_level_tables;
last_tab->next_select= end_send;
last_tab->cached_pfs_batch_update= last_tab->pfs_batch_update();
enum_nested_loop_state state= last_tab->aggr->end_send();
if (state >= NESTED_LOOP_OK)
@ -22154,6 +22199,7 @@ do_select(JOIN *join, Procedure *procedure)
join->procedure= procedure;
join->duplicate_rows= join->send_records=0;
if (join->only_const_tables() && !join->need_tmp)
{
Next_select_func end_select= setup_end_select_func(join, NULL);
@ -22226,6 +22272,17 @@ do_select(JOIN *join, Procedure *procedure)
dbug_serve_apcs(join->thd, 1);
);
/*
We have to update the cached_pfs_batch_update as
join_tab->select_cond may have changed.
This can happen in case of group by where some sub queries are not
needed anymore. This is checked by main.ps
*/
if (top_level_tables)
join->join_tab[top_level_tables-1].cached_pfs_batch_update=
join->join_tab[top_level_tables-1].pfs_batch_update();
JOIN_TAB *join_tab= join->join_tab +
(join->tables_list ? join->const_tables : 0);
if (join->outer_ref_cond && !join->outer_ref_cond->val_int())
@ -22617,6 +22674,8 @@ sub_select_cache(JOIN *join, JOIN_TAB *join_tab, bool end_of_records)
enum_nested_loop_state
sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
{
int error;
enum_nested_loop_state rc;
DBUG_ENTER("sub_select");
if (join_tab->last_inner)
@ -22636,10 +22695,7 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
}
join_tab->tracker->r_scans++;
int error;
enum_nested_loop_state rc= NESTED_LOOP_OK;
READ_RECORD *info= &join_tab->read_record;
rc= NESTED_LOOP_OK;
for (SJ_TMP_TABLE *flush_dups_table= join_tab->flush_weedout_table;
flush_dups_table;
@ -22651,9 +22707,21 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
if (!join_tab->preread_init_done && join_tab->preread_init())
DBUG_RETURN(NESTED_LOOP_ERROR);
join_tab->build_range_rowid_filter_if_needed();
if (join_tab->rowid_filter && join_tab->rowid_filter->is_empty())
rc= NESTED_LOOP_NO_MORE_ROWS;
if (unlikely(join_tab->rowid_filter))
{
if (unlikely(join_tab->need_to_build_rowid_filter))
{
join_tab->build_range_rowid_filter();
/*
We have to check join_tab->rowid_filter again as the above
function may have cleared it in case of errors.
*/
if (join_tab->rowid_filter && join_tab->rowid_filter->is_empty())
rc= NESTED_LOOP_NO_MORE_ROWS;
}
else if (join_tab->rowid_filter->is_empty())
rc= NESTED_LOOP_NO_MORE_ROWS;
}
join->return_tab= join_tab;
@ -22679,8 +22747,8 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
if (join_tab->loosescan_match_tab)
join_tab->loosescan_match_tab->found_match= FALSE;
const bool pfs_batch_update= join_tab->pfs_batch_update(join);
if (pfs_batch_update)
DBUG_ASSERT(join_tab->cached_pfs_batch_update == join_tab->pfs_batch_update());
if (join_tab->cached_pfs_batch_update)
join_tab->table->file->start_psi_batch_mode();
if (rc != NESTED_LOOP_NO_MORE_ROWS)
@ -22691,11 +22759,9 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
rc= evaluate_join_record(join, join_tab, error);
}
/*
Note: psergey has added the 2nd part of the following condition; the
change should probably be made in 5.1, too.
*/
bool skip_over= FALSE;
READ_RECORD *info= &join_tab->read_record;
while (rc == NESTED_LOOP_OK && join->return_tab >= join_tab)
{
if (join_tab->loosescan_match_tab &&
@ -22730,15 +22796,21 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
rc= evaluate_join_record(join, join_tab, error);
}
if (rc == NESTED_LOOP_NO_MORE_ROWS &&
join_tab->last_inner && !join_tab->found)
rc= evaluate_null_complemented_join_record(join, join_tab);
if (rc == NESTED_LOOP_NO_MORE_ROWS)
{
if (join_tab->last_inner && !join_tab->found)
{
rc= evaluate_null_complemented_join_record(join, join_tab);
if (rc == NESTED_LOOP_NO_MORE_ROWS)
rc= NESTED_LOOP_OK;
}
else
rc= NESTED_LOOP_OK;
}
if (pfs_batch_update)
if (join_tab->cached_pfs_batch_update)
join_tab->table->file->end_psi_batch_mode();
if (rc == NESTED_LOOP_NO_MORE_ROWS)
rc= NESTED_LOOP_OK;
DBUG_RETURN(rc);
}
@ -22765,7 +22837,6 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
ha_rows found_records=join->found_records;
COND *select_cond= join_tab->select_cond;
bool select_cond_result= TRUE;
DBUG_ENTER("evaluate_join_record");
DBUG_PRINT("enter",
("evaluate_join_record join: %p join_tab: %p "
@ -22793,7 +22864,7 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
DBUG_RETURN(NESTED_LOOP_ERROR);
}
if (!select_cond || select_cond_result)
if (select_cond_result)
{
/*
There is no select condition or the attached pushed down
@ -23643,7 +23714,8 @@ int join_init_read_record(JOIN_TAB *tab)
need_unpacking= tbl ? tbl->is_sjm_scan_table() : FALSE;
}
tab->build_range_rowid_filter_if_needed();
if (tab->need_to_build_rowid_filter)
tab->build_range_rowid_filter();
if (tab->filesort && tab->sort_table()) // Sort table.
return 1;
@ -25770,8 +25842,9 @@ check_reverse_order:
select->quick= 0; // Cleanup either reset to save_quick,
// or 'delete save_quick'
tab->index= best_key;
tab->read_first_record= order_direction > 0 ?
join_read_first:join_read_last;
tab->read_first_record= (order_direction > 0 ?
join_read_first:
join_read_last);
tab->type=JT_NEXT; // Read with index_first(), index_next()
/*
@ -25780,11 +25853,7 @@ check_reverse_order:
*/
if (tab->rowid_filter &&
table->file->is_clustering_key(tab->index))
{
tab->range_rowid_filter_info= 0;
delete tab->rowid_filter;
tab->rowid_filter= 0;
}
tab->clear_range_rowid_filter();
if (tab->pre_idx_push_select_cond)
{
@ -25818,12 +25887,8 @@ check_reverse_order:
tab->use_quick=1;
tab->ref.key= -1;
tab->ref.key_parts=0; // Don't use ref key.
tab->range_rowid_filter_info= 0;
if (tab->rowid_filter)
{
delete tab->rowid_filter;
tab->rowid_filter= 0;
}
tab->clear_range_rowid_filter();
tab->read_first_record= join_init_read_record;
if (tab->is_using_loose_index_scan())
tab->join->tmp_table_param.precomputed_group_by= TRUE;

11
sql/sql_select.h
View File

@ -423,6 +423,8 @@ typedef struct st_join_table {
bool cached_eq_ref_table,eq_ref_table;
bool shortcut_for_distinct;
bool sorted;
bool cached_pfs_batch_update;
/*
If it's not 0 the number stored this field indicates that the index
scan has been chosen to access the table data and we expect to scan
@ -571,10 +573,11 @@ typedef struct st_join_table {
Range_rowid_filter_cost_info *range_rowid_filter_info;
/* Rowid filter to be used when joining this join table */
Rowid_filter *rowid_filter;
/* Becomes true just after the used range filter has been built / filled */
bool is_rowid_filter_built;
/* True if the plan requires a rowid filter and it's not built yet */
bool need_to_build_rowid_filter;
void build_range_rowid_filter_if_needed();
void build_range_rowid_filter();
void clear_range_rowid_filter();
void cleanup();
inline bool is_using_loose_index_scan()
@ -685,7 +688,7 @@ typedef struct st_join_table {
double get_examined_rows();
bool preread_init();
bool pfs_batch_update(JOIN *join);
bool pfs_batch_update();
bool is_sjm_nest() { return MY_TEST(bush_children); }