[Commits] a78365c11ac: MDEV-18553: MDEV-16327 pre-requisits isolation of LIMIT/OFFSET handling

revision-id: a78365c11ac8b8ac2697a185d2516152a44f3dfe (mariadb-10.4.1-78-ga78365c11ac) parent(s): d97a26a67dca82d166e9edefe5f950ea8a110dfd author: Oleksandr Byelkin committer: Oleksandr Byelkin timestamp: 2019-02-13 09:54:51 +0100 message: MDEV-18553: MDEV-16327 pre-requisits isolation of LIMIT/OFFSET handling --- sql/group_by_handler.cc | 8 +++---- sql/group_by_handler.h | 1 + sql/item_subselect.cc | 2 +- sql/opt_subselect.cc | 9 +++----- sql/sql_class.cc | 44 +++++++++++------------------------- sql/sql_class.h | 6 ++--- sql/sql_derived.cc | 2 +- sql/sql_error.cc | 10 ++++----- sql/sql_insert.cc | 7 ++---- sql/sql_lex.cc | 10 ++------- sql/sql_lex.h | 59 ++++++++++++++++++++++++++++++++++++++++++++++++- sql/sql_parse.cc | 13 ++++++----- sql/sql_profile.cc | 10 ++++----- sql/sql_repl.cc | 10 ++++----- sql/sql_select.cc | 46 ++++++++++++++++++++------------------ sql/sql_union.cc | 36 +++++++++++++----------------- 16 files changed, 148 insertions(+), 125 deletions(-) diff --git a/sql/group_by_handler.cc b/sql/group_by_handler.cc index f18758a2d94..f5ed24370b1 100644 --- a/sql/group_by_handler.cc +++ b/sql/group_by_handler.cc @@ -40,7 +40,7 @@ int Pushdown_query::execute(JOIN *join) { int err; ha_rows max_limit; - ha_rows *reset_limit= 0; + bool reset_limit= FALSE; Item **reset_item= 0; THD *thd= handler->thd; TABLE *table= handler->table; @@ -52,11 +52,11 @@ int Pushdown_query::execute(JOIN *join) if (store_data_in_temp_table) { max_limit= join->tmp_table_param.end_write_records; - reset_limit= &join->unit->select_limit_cnt; + reset_limit= TRUE; } else { - max_limit= join->unit->select_limit_cnt; + max_limit= join->unit->lim.get_select_limit(); if (join->unit->fake_select_lex) reset_item= &join->unit->fake_select_lex->select_limit; } @@ -112,7 +112,7 @@ int Pushdown_query::execute(JOIN *join) break; // LIMIT reached join->do_send_rows= 0; // Calculate FOUND_ROWS() if (reset_limit) - *reset_limit= HA_POS_ERROR; + join->unit->lim.set_unlimited(); if (reset_item) *reset_item= 0; } diff --git a/sql/group_by_handler.h b/sql/group_by_handler.h index d3f48a15c24..be981f0da5f 100644 --- a/sql/group_by_handler.h +++ b/sql/group_by_handler.h @@ -56,6 +56,7 @@ struct Query ORDER *order_by; Item *having; // LIMIT + //ha_rows select_limit_cnt, offset_limit_cnt; }; class group_by_handler diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc index 0ace59fd2fc..e860c3fa98d 100644 --- a/sql/item_subselect.cc +++ b/sql/item_subselect.cc @@ -2721,7 +2721,7 @@ bool Item_in_subselect::inject_in_to_exists_cond(JOIN *join_arg) join_arg->thd->change_item_tree(&unit->global_parameters()->select_limit, new (thd->mem_root) Item_int(thd, (int32) 1)); - unit->select_limit_cnt= 1; + unit->lim.set_single_row(); DBUG_RETURN(false); } diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc index c4c30c9b50d..e9284926385 100644 --- a/sql/opt_subselect.cc +++ b/sql/opt_subselect.cc @@ -5492,11 +5492,8 @@ int select_value_catcher::send_data(List<Item> &items) DBUG_ASSERT(!assigned); DBUG_ASSERT(items.elements == n_elements); - if (unit->offset_limit_cnt) - { // Using limit offset,count - unit->offset_limit_cnt--; - DBUG_RETURN(0); - } + if (unit->lim.check_and_move_offset()) + DBUG_RETURN(0); // Using limit offset,count Item *val_item; List_iterator_fast<Item> li(items); @@ -6289,7 +6286,7 @@ bool JOIN::choose_subquery_plan(table_map join_tables) Set the limit of this JOIN object as well, because normally its being set in the beginning of JOIN::optimize, which was already done. */ - select_limit= in_subs->unit->select_limit_cnt; + select_limit= in_subs->unit->lim.get_select_limit(); } else if (in_subs->test_strategy(SUBS_IN_TO_EXISTS)) { diff --git a/sql/sql_class.cc b/sql/sql_class.cc index 2952adbd3e6..ce6d71082fb 100644 --- a/sql/sql_class.cc +++ b/sql/sql_class.cc @@ -2936,11 +2936,8 @@ int select_send::send_data(List<Item> &items) DBUG_ENTER("select_send::send_data"); /* unit is not set when using 'delete ... returning' */ - if (unit && unit->offset_limit_cnt) - { // using limit offset,count - unit->offset_limit_cnt--; - DBUG_RETURN(FALSE); - } + if (unit && unit->lim.check_and_move_offset()) + DBUG_RETURN(FALSE); // using limit offset,count if (thd->killed == ABORT_QUERY) DBUG_RETURN(FALSE); @@ -3205,11 +3202,8 @@ int select_export::send_data(List<Item> &items) String tmp(buff,sizeof(buff),&my_charset_bin),*res; tmp.length(0); - if (unit->offset_limit_cnt) - { // using limit offset,count - unit->offset_limit_cnt--; - DBUG_RETURN(0); - } + if (unit->lim.check_and_move_offset()) + DBUG_RETURN(0); // using limit offset,count if (thd->killed == ABORT_QUERY) DBUG_RETURN(0); row_count++; @@ -3465,11 +3459,8 @@ int select_dump::send_data(List<Item> &items) Item *item; DBUG_ENTER("select_dump::send_data"); - if (unit->offset_limit_cnt) - { // using limit offset,count - unit->offset_limit_cnt--; - DBUG_RETURN(0); - } + if (unit->lim.check_and_move_offset()) + DBUG_RETURN(0); // using limit offset,count if (thd->killed == ABORT_QUERY) DBUG_RETURN(0); @@ -3508,11 +3499,8 @@ int select_singlerow_subselect::send_data(List<Item> &items) MYF(current_thd->lex->ignore ? ME_WARNING : 0)); DBUG_RETURN(1); } - if (unit->offset_limit_cnt) - { // Using limit offset,count - unit->offset_limit_cnt--; - DBUG_RETURN(0); - } + if (unit->lim.check_and_move_offset()) + DBUG_RETURN(0); // Using limit offset,count if (thd->killed == ABORT_QUERY) DBUG_RETURN(0); List_iterator_fast<Item> li(items); @@ -3649,11 +3637,8 @@ int select_exists_subselect::send_data(List<Item> &items) { DBUG_ENTER("select_exists_subselect::send_data"); Item_exists_subselect *it= (Item_exists_subselect *)item; - if (unit->offset_limit_cnt) - { // Using limit offset,count - unit->offset_limit_cnt--; - DBUG_RETURN(0); - } + if (unit->lim.check_and_move_offset()) + DBUG_RETURN(0); // Using limit offset,count if (thd->killed == ABORT_QUERY) DBUG_RETURN(0); it->value= 1; @@ -4060,12 +4045,9 @@ int select_dumpvar::send_data(List<Item> &items) { DBUG_ENTER("select_dumpvar::send_data"); - if (unit->offset_limit_cnt) - { // using limit offset,count - unit->offset_limit_cnt--; - DBUG_RETURN(0); - } - if (row_count++) + if (unit->lim.check_and_move_offset()) + DBUG_RETURN(0); // using limit offset,count + if (row_count++) { my_message(ER_TOO_MANY_ROWS, ER_THD(thd, ER_TOO_MANY_ROWS), MYF(0)); DBUG_RETURN(1); diff --git a/sql/sql_class.h b/sql/sql_class.h index b1da6e19247..7427b2745bc 100644 --- a/sql/sql_class.h +++ b/sql/sql_class.h @@ -5117,9 +5117,9 @@ class select_result :public select_result_sink /* this method is called just before the first row of the table can be read */ virtual void prepare_to_read_rows() {} - void reset_offset_limit() + void remove_offset_limit() { - unit->offset_limit_cnt= 0; + unit->lim.remove_offset(); } /* @@ -5786,7 +5786,7 @@ class select_union_direct :public select_unit */ DBUG_ASSERT(false); /* purecov: inspected */ } - void reset_offset_limit_cnt() + void remove_offset_limit() { // EXPLAIN should never output to a select_union_direct DBUG_ASSERT(false); /* purecov: inspected */ diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc index 878aa715b84..4fd44a18550 100644 --- a/sql/sql_derived.cc +++ b/sql/sql_derived.cc @@ -1148,7 +1148,7 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived) { SELECT_LEX *first_select= unit->first_select(); unit->set_limit(unit->global_parameters()); - if (unit->select_limit_cnt == HA_POS_ERROR) + if (unit->lim.is_unlimited()) first_select->options&= ~OPTION_FOUND_ROWS; lex->current_select= first_select; diff --git a/sql/sql_error.cc b/sql/sql_error.cc index 8d639f9271d..6bb36dbb089 100644 --- a/sql/sql_error.cc +++ b/sql/sql_error.cc @@ -783,7 +783,7 @@ bool mysqld_show_warnings(THD *thd, ulong levels_to_show) const Sql_condition *err; SELECT_LEX *sel= thd->lex->first_select_lex(); SELECT_LEX_UNIT *unit= &thd->lex->unit; - ulonglong idx= 0; + ha_rows idx; Protocol *protocol=thd->protocol; DBUG_ENTER("mysqld_show_warnings"); @@ -808,14 +808,14 @@ bool mysqld_show_warnings(THD *thd, ulong levels_to_show) Diagnostics_area::Sql_condition_iterator it= thd->get_stmt_da()->sql_conditions(); - while ((err= it++)) + for (idx= 1; (err= it++) ; idx++) { /* Skip levels that the user is not interested in */ if (!(levels_to_show & ((ulong) 1 << err->get_level()))) continue; - if (++idx <= unit->offset_limit_cnt) - continue; - if (idx > unit->select_limit_cnt) + if (unit->lim.check_and_move_offset()) + continue; // using limit offset,count + if (idx > unit->lim.get_select_limit()) break; protocol->prepare_for_resend(); protocol->store(warning_level_names[err->get_level()].str, diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc index f5e4185db92..c4f60f0551c 100644 --- a/sql/sql_insert.cc +++ b/sql/sql_insert.cc @@ -3840,11 +3840,8 @@ int select_insert::send_data(List<Item> &values) DBUG_ENTER("select_insert::send_data"); bool error=0; - if (unit->offset_limit_cnt) - { // using limit offset,count - unit->offset_limit_cnt--; - DBUG_RETURN(0); - } + if (unit->lim.check_and_move_offset()) + DBUG_RETURN(0); // using limit offset,count if (unlikely(thd->killed == ABORT_QUERY)) DBUG_RETURN(0); diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc index 1b8f448553b..2c298a17391 100644 --- a/sql/sql_lex.cc +++ b/sql/sql_lex.cc @@ -2321,8 +2321,7 @@ void st_select_lex_unit::init_query() { init_query_common(); set_linkage(GLOBAL_OPTIONS_TYPE); - select_limit_cnt= HA_POS_ERROR; - offset_limit_cnt= 0; + lim.set_unlimited(); union_distinct= 0; prepared= optimized= optimized_2= executed= 0; optimize_started= 0; @@ -3462,12 +3461,7 @@ void st_select_lex_unit::set_limit(st_select_lex *sl) { DBUG_ASSERT(!thd->stmt_arena->is_stmt_prepare()); - offset_limit_cnt= sl->get_offset(); - select_limit_cnt= sl->get_limit(); - if (select_limit_cnt + offset_limit_cnt >= select_limit_cnt) - select_limit_cnt+= offset_limit_cnt; - else - select_limit_cnt= HA_POS_ERROR; + lim.set_limit(sl->get_limit(), sl->get_offset()); } diff --git a/sql/sql_lex.h b/sql/sql_lex.h index 40ba3b6e7b7..0270a4acfcc 100644 --- a/sql/sql_lex.h +++ b/sql/sql_lex.h @@ -816,6 +816,63 @@ void create_explain_query(LEX *lex, MEM_ROOT *mem_root); void create_explain_query_if_not_exists(LEX *lex, MEM_ROOT *mem_root); bool print_explain_for_slow_log(LEX *lex, THD *thd, String *str); +class Select_limit_counters +{ + ha_rows offset_limit_cnt_start, + select_limit_cnt, offset_limit_cnt; + + public: + Select_limit_counters(): + offset_limit_cnt_start(0), + select_limit_cnt(0), offset_limit_cnt(0) + {}; + + void set_limit(ha_rows limit, ha_rows offset) + { + offset_limit_cnt_start= offset; + select_limit_cnt= limit; + if (select_limit_cnt + offset_limit_cnt_start >= + select_limit_cnt) + select_limit_cnt+= offset_limit_cnt_start; + else + select_limit_cnt= HA_POS_ERROR; + reset(); + } + + void set_single_row() + { + offset_limit_cnt= offset_limit_cnt_start= 0; + select_limit_cnt= 1; + } + + void reset() + { + offset_limit_cnt= offset_limit_cnt_start; + } + + bool is_unlimited() + { return select_limit_cnt == HA_POS_ERROR; } + void set_unlimited() + { select_limit_cnt= HA_POS_ERROR; offset_limit_cnt= 0; } + + bool check_and_move_offset() + { + if (offset_limit_cnt) + { + offset_limit_cnt--; + return TRUE; + } + return FALSE; + } + void remove_offset() { offset_limit_cnt= 0; } + + ha_rows get_select_limit() + { return select_limit_cnt; } + ha_rows get_offset_limit() + { return offset_limit_cnt; } +}; + + class st_select_lex_unit: public st_select_lex_node { protected: TABLE_LIST result_table_list; @@ -891,7 +948,7 @@ class st_select_lex_unit: public st_select_lex_node { //node on which we should return current_select pointer after parsing subquery st_select_lex *return_to; /* LIMIT clause runtime counters */ - ha_rows select_limit_cnt, offset_limit_cnt; + Select_limit_counters lim; /* not NULL if unit used in subselect, point to subselect item */ Item_subselect *item; /* diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc index 7d6f71cda21..9e6600d65b6 100644 --- a/sql/sql_parse.cc +++ b/sql/sql_parse.cc @@ -4579,7 +4579,7 @@ mysql_execute_command(THD *thd) select_lex->where, select_lex->order_list.elements, select_lex->order_list.first, - unit->select_limit_cnt, + unit->lim.get_select_limit(), lex->duplicates, lex->ignore, &found, &updated); MYSQL_UPDATE_DONE(res, found, updated); @@ -4924,7 +4924,7 @@ mysql_execute_command(THD *thd) res = mysql_delete(thd, all_tables, select_lex->where, &select_lex->order_list, - unit->select_limit_cnt, select_lex->options, + unit->lim.get_select_limit(), select_lex->options, sel_result); if (replaced_protocol) @@ -5771,7 +5771,8 @@ mysql_execute_command(THD *thd) res= mysql_ha_read(thd, first_table, lex->ha_read_mode, lex->ident.str, lex->insert_list, lex->ha_rkey_mode, select_lex->where, - unit->select_limit_cnt, unit->offset_limit_cnt); + unit->lim.get_select_limit(), + unit->lim.get_offset_limit()); break; case SQLCOM_BEGIN: @@ -6511,8 +6512,8 @@ static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables) /* Do like the original select_describe did: remove OFFSET from the top-level LIMIT - */ - result->reset_offset_limit(); + */ + result->remove_offset_limit(); if (lex->explain_json) { lex->explain->print_explain_json(result, lex->analyze_stmt); @@ -7853,7 +7854,7 @@ void mysql_init_multi_delete(LEX *lex) lex->sql_command= SQLCOM_DELETE_MULTI; mysql_init_select(lex); lex->first_select_lex()->select_limit= 0; - lex->unit.select_limit_cnt= HA_POS_ERROR; + lex->unit.lim.set_unlimited(); lex->first_select_lex()->table_list. save_and_clear(&lex->auxiliary_table_list); lex->query_tables= 0; diff --git a/sql/sql_profile.cc b/sql/sql_profile.cc index 6ca21aebb37..e2b7b18faac 100644 --- a/sql/sql_profile.cc +++ b/sql/sql_profile.cc @@ -404,7 +404,7 @@ bool PROFILING::show_profiles() MEM_ROOT *mem_root= thd->mem_root; SELECT_LEX *sel= thd->lex->first_select_lex(); SELECT_LEX_UNIT *unit= &thd->lex->unit; - ha_rows idx= 0; + ha_rows idx; Protocol *protocol= thd->protocol; void *iterator; DBUG_ENTER("PROFILING::show_profiles"); @@ -428,9 +428,9 @@ bool PROFILING::show_profiles() unit->set_limit(sel); - for (iterator= history.new_iterator(); + for (iterator= history.new_iterator(), idx= 1; iterator != NULL; - iterator= history.iterator_next(iterator)) + iterator= history.iterator_next(iterator), idx++) { prof= history.iterator_value(iterator); @@ -438,9 +438,9 @@ bool PROFILING::show_profiles() double query_time_usecs= prof->m_end_time_usecs - prof->m_start_time_usecs; - if (++idx <= unit->offset_limit_cnt) + if (unit->lim.check_and_move_offset()) continue; - if (idx > unit->select_limit_cnt) + if (idx > unit->lim.get_select_limit()) break; protocol->prepare_for_resend(); diff --git a/sql/sql_repl.cc b/sql/sql_repl.cc index 2ee175293de..6f712750e41 100644 --- a/sql/sql_repl.cc +++ b/sql/sql_repl.cc @@ -3911,7 +3911,7 @@ bool mysql_show_binlog_events(THD* thd) if (binary_log->is_open()) { SELECT_LEX_UNIT *unit= &thd->lex->unit; - ha_rows event_count, limit_start, limit_end; + ha_rows event_count; my_off_t pos = MY_MAX(BIN_LOG_HEADER_SIZE, lex_mi->pos); // user-friendly char search_file_name[FN_REFLEN], *name; const char *log_file_name = lex_mi->log_file_name; @@ -3926,8 +3926,6 @@ bool mysql_show_binlog_events(THD* thd) } unit->set_limit(thd->lex->current_select); - limit_start= unit->offset_limit_cnt; - limit_end= unit->select_limit_cnt; name= search_file_name; if (log_file_name) @@ -4006,7 +4004,7 @@ bool mysql_show_binlog_events(THD* thd) description_event, opt_master_verify_checksum)); ) { - if (event_count >= limit_start && + if (!unit->lim.check_and_move_offset() && ev->net_send(protocol, linfo.log_file_name, pos)) { errmsg = "Net error"; @@ -4040,11 +4038,11 @@ bool mysql_show_binlog_events(THD* thd) pos = my_b_tell(&log); - if (++event_count >= limit_end) + if (++event_count >= unit->lim.get_select_limit()) break; } - if (unlikely(event_count < limit_end && log.error)) + if (unlikely(event_count < unit->lim.get_select_limit() && log.error)) { errmsg = "Wrong offset or I/O error"; mysql_mutex_unlock(log_lock); diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 978f0785887..aa4c40866a9 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -1508,7 +1508,7 @@ JOIN::optimize_inner() { DBUG_ENTER("JOIN::optimize"); subq_exit_fl= false; - do_send_rows = (unit->select_limit_cnt) ? 1 : 0; + do_send_rows = (unit->lim.get_select_limit()) ? 1 : 0; DEBUG_SYNC(thd, "before_join_optimize"); @@ -1579,9 +1579,9 @@ JOIN::optimize_inner() DBUG_RETURN(-1); row_limit= ((select_distinct || order || group_list) ? HA_POS_ERROR : - unit->select_limit_cnt); + unit->lim.get_select_limit()); /* select_limit is used to decide if we are likely to scan the whole table */ - select_limit= unit->select_limit_cnt; + select_limit= unit->lim.get_select_limit(); if (having || (select_options & OPTION_FOUND_ROWS)) select_limit= HA_POS_ERROR; #ifdef HAVE_REF_TO_FIELDS // Not done yet @@ -1790,9 +1790,10 @@ JOIN::optimize_inner() thd->change_item_tree(&sel->having, having); } if (cond_value == Item::COND_FALSE || having_value == Item::COND_FALSE || - (!unit->select_limit_cnt && !(select_options & OPTION_FOUND_ROWS))) + (!unit->lim.get_select_limit() && + !(select_options & OPTION_FOUND_ROWS))) { /* Impossible cond */ - if (unit->select_limit_cnt) + if (unit->lim.get_select_limit()) { DBUG_PRINT("info", (having_value == Item::COND_FALSE ? "Impossible HAVING" : "Impossible WHERE")); @@ -3314,7 +3315,7 @@ bool JOIN::make_aggr_tables_info() */ sort_tab->filesort->limit= (has_group_by || (join_tab + table_count > curr_tab + 1)) ? - select_limit : unit->select_limit_cnt; + select_limit : unit->lim.get_select_limit(); } if (!only_const_tables() && !join_tab[const_tables].filesort && @@ -3698,8 +3699,7 @@ JOIN::reinit() { DBUG_ENTER("JOIN::reinit"); - unit->offset_limit_cnt= (ha_rows)(select_lex->offset_limit ? - select_lex->offset_limit->val_uint() : 0); + unit->lim.reset(); first_record= false; group_sent= false; @@ -5157,7 +5157,7 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list, for (i= 0; i < join->table_count ; i++) records*= join->best_positions[i].records_read ? (ha_rows)join->best_positions[i].records_read : 1; - set_if_smaller(records, unit->select_limit_cnt); + set_if_smaller(records, unit->lim.get_select_limit()); join->select_lex->increase_derived_records(records); } } @@ -7446,7 +7446,7 @@ best_access_path(JOIN *join, if (!best_key && idx == join->const_tables && s->table == join->sort_by_table && - join->unit->select_limit_cnt >= records) + join->unit->lim.get_select_limit() >= records) join->sort_by_table= (TABLE*) 1; // Must use temporary table DBUG_VOID_RETURN; @@ -10799,7 +10799,7 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond) !tab->loosescan_match_tab && // (1) ((cond && (!tab->keys.is_subset(tab->const_keys) && i > 0)) || (!tab->const_keys.is_clear_all() && i == join->const_tables && - join->unit->select_limit_cnt < + join->unit->lim.get_select_limit() < join->best_positions[i].records_read && !(join->select_options & OPTION_FOUND_ROWS)))) { @@ -10823,7 +10823,7 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond) (join->select_options & OPTION_FOUND_ROWS ? HA_POS_ERROR : - join->unit->select_limit_cnt), 0, + join->unit->lim.get_select_limit()), 0, FALSE, FALSE) < 0) { /* @@ -10837,7 +10837,7 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond) (join->select_options & OPTION_FOUND_ROWS ? HA_POS_ERROR : - join->unit->select_limit_cnt),0, + join->unit->lim.get_select_limit()),0, FALSE, FALSE) < 0) DBUG_RETURN(1); // Impossible WHERE } @@ -20581,7 +20581,7 @@ end_send(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), } ++join->send_records; - if (join->send_records >= join->unit->select_limit_cnt && + if (join->send_records >= join->unit->lim.get_select_limit() && !join->do_send_rows) { /* @@ -20599,7 +20599,7 @@ end_send(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), DBUG_RETURN(NESTED_LOOP_QUERY_LIMIT); } } - if (join->send_records >= join->unit->select_limit_cnt && + if (join->send_records >= join->unit->lim.get_select_limit() && join->do_send_rows) { if (join->select_options & OPTION_FOUND_ROWS) @@ -20740,13 +20740,13 @@ end_send_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), DBUG_RETURN(NESTED_LOOP_ERROR); /* purecov: inspected */ if (end_of_records) DBUG_RETURN(NESTED_LOOP_OK); - if (join->send_records >= join->unit->select_limit_cnt && + if (join->send_records >= join->unit->lim.get_select_limit() && join->do_send_rows) { if (!(join->select_options & OPTION_FOUND_ROWS)) DBUG_RETURN(NESTED_LOOP_QUERY_LIMIT); // Abort nicely join->do_send_rows=0; - join->unit->select_limit_cnt = HA_POS_ERROR; + join->unit->lim.set_unlimited(); } else if (join->send_records >= join->fetch_limit) { @@ -20831,7 +20831,7 @@ end_write(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)), if (!(join->select_options & OPTION_FOUND_ROWS)) DBUG_RETURN(NESTED_LOOP_QUERY_LIMIT); join->do_send_rows=0; - join->unit->select_limit_cnt = HA_POS_ERROR; + join->unit->lim.set_unlimited(); } } } @@ -22142,7 +22142,9 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit, (tab->join->select_options & OPTION_FOUND_ROWS) ? HA_POS_ERROR : - tab->join->unit->select_limit_cnt,TRUE, + tab->join->unit-> + lim.get_select_limit(), + TRUE, TRUE, FALSE) <= 0; if (res) { @@ -22244,7 +22246,7 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit, select->test_quick_select(join->thd, tmp_map, 0, join->select_options & OPTION_FOUND_ROWS ? HA_POS_ERROR : - join->unit->select_limit_cnt, + join->unit->lim.get_select_limit(), TRUE, FALSE, FALSE); if (cond_saved) @@ -22671,7 +22673,7 @@ JOIN_TAB::remove_duplicates() if (!field_count && !(join->select_options & OPTION_FOUND_ROWS) && !having) { // only const items with no OPTION_FOUND_ROWS - join->unit->select_limit_cnt= 1; // Only send first row + join->unit->lim.set_single_row(); // Only send first row DBUG_RETURN(false); } @@ -24859,7 +24861,7 @@ int JOIN::rollup_send_data(uint idx) copy_ref_ptr_array(ref_ptrs, rollup.ref_pointer_arrays[i]); if ((!having || having->val_int())) { - if (send_records < unit->select_limit_cnt && do_send_rows && + if (send_records < unit->lim.get_select_limit() && do_send_rows && (res= result->send_data(rollup.fields[i])) > 0) return 1; if (!res) diff --git a/sql/sql_union.cc b/sql/sql_union.cc index ca8a5e7a8b3..d563301a339 100644 --- a/sql/sql_union.cc +++ b/sql/sql_union.cc @@ -110,11 +110,8 @@ int select_unit::send_data(List<Item> &values) { int rc; int not_reported_error= 0; - if (unit->offset_limit_cnt) - { // using limit offset,count - unit->offset_limit_cnt--; - return 0; - } + if (unit->lim.check_and_move_offset()) + return 0; // using limit offset,count if (thd->killed == ABORT_QUERY) return 0; if (table->no_rows_with_nulls) @@ -883,8 +880,7 @@ bool st_select_lex_unit::prepare(TABLE_LIST *derived_arg, else { sl->join->result= result; - select_limit_cnt= HA_POS_ERROR; - offset_limit_cnt= 0; + lim.set_unlimited(); if (!sl->join->procedure && result->prepare(sl->join->fields_list, this)) { @@ -1317,7 +1313,7 @@ bool st_select_lex_unit::optimize() if (sl->tvc) { sl->tvc->select_options= - (select_limit_cnt == HA_POS_ERROR || sl->braces) ? + (lim.is_unlimited() || sl->braces) ? sl->options & ~OPTION_FOUND_ROWS : sl->options | found_rows_for_union; if (sl->tvc->optimize(thd)) { @@ -1337,13 +1333,13 @@ bool st_select_lex_unit::optimize() set_limit(sl); if (sl == global_parameters() || describe) { - offset_limit_cnt= 0; + lim.remove_offset(); /* We can't use LIMIT at this stage if we are using ORDER BY for the whole query */ if (sl->order_list.first || describe) - select_limit_cnt= HA_POS_ERROR; + lim.set_unlimited(); } /* @@ -1352,7 +1348,7 @@ bool st_select_lex_unit::optimize() Otherwise, SQL_CALC_FOUND_ROWS should be done on all sub parts. */ sl->join->select_options= - (select_limit_cnt == HA_POS_ERROR || sl->braces) ? + (lim.is_unlimited() || sl->braces) ? sl->options & ~OPTION_FOUND_ROWS : sl->options | found_rows_for_union; saved_error= sl->join->optimize(); @@ -1432,13 +1428,13 @@ bool st_select_lex_unit::exec() set_limit(sl); if (sl == global_parameters() || describe) { - offset_limit_cnt= 0; + lim.remove_offset(); /* We can't use LIMIT at this stage if we are using ORDER BY for the whole query */ if (sl->order_list.first || describe) - select_limit_cnt= HA_POS_ERROR; + lim.set_unlimited(); } /* @@ -1449,14 +1445,14 @@ bool st_select_lex_unit::exec() if (sl->tvc) { sl->tvc->select_options= - (select_limit_cnt == HA_POS_ERROR || sl->braces) ? + (lim.is_unlimited() || sl->braces) ? sl->options & ~OPTION_FOUND_ROWS : sl->options | found_rows_for_union; saved_error= sl->tvc->optimize(thd); } else { - sl->join->select_options= - (select_limit_cnt == HA_POS_ERROR || sl->braces) ? + sl->join->select_options= + (lim.is_unlimited() || sl->braces) ? sl->options & ~OPTION_FOUND_ROWS : sl->options | found_rows_for_union; saved_error= sl->join->optimize(); } @@ -1478,9 +1474,7 @@ bool st_select_lex_unit::exec() } if (!sl->tvc) saved_error= sl->join->error; - offset_limit_cnt= (ha_rows)(sl->offset_limit ? - sl->offset_limit->val_uint() : - 0); + lim.reset(); if (likely(!saved_error)) { examined_rows+= thd->get_examined_row_count(); @@ -1507,8 +1501,8 @@ bool st_select_lex_unit::exec() DBUG_RETURN(1); } } - if (found_rows_for_union && !sl->braces && - select_limit_cnt != HA_POS_ERROR) + if (found_rows_for_union && !sl->braces && + !lim.is_unlimited()) { /* This is a union without braces. Remember the number of rows that