diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 293 |
1 files changed, 238 insertions, 55 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 47af428ed56..30a91e882fe 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -159,6 +159,7 @@ static int join_read_const_table(JOIN_TAB *tab, POSITION *pos); static int join_read_system(JOIN_TAB *tab); static int join_read_const(JOIN_TAB *tab); static int join_read_key(JOIN_TAB *tab); +static void join_read_key_unlock_row(st_join_table *tab); static int join_read_always_key(JOIN_TAB *tab); static int join_read_last_key(JOIN_TAB *tab); static int join_no_more_records(READ_RECORD *info); @@ -643,6 +644,18 @@ JOIN::prepare(Item ***rref_pointer_array, MYF(0)); /* purecov: inspected */ goto err; /* purecov: inspected */ } + if (thd->lex->derived_tables) + { + my_error(ER_WRONG_USAGE, MYF(0), "PROCEDURE", + thd->lex->derived_tables & DERIVED_VIEW ? + "view" : "subquery"); + goto err; + } + if (thd->lex->sql_command != SQLCOM_SELECT) + { + my_error(ER_WRONG_USAGE, MYF(0), "PROCEDURE", "non-SELECT"); + goto err; + } } if (!procedure && result && result->prepare(fields_list, unit_arg)) @@ -654,8 +667,11 @@ JOIN::prepare(Item ***rref_pointer_array, this->group= group_list != 0; unit= unit_arg; + if (tmp_table_param.sum_func_count && !group_list) + implicit_grouping= TRUE; + #ifdef RESTRICTED_GROUP - if (sum_func_count && !group_list && (func_count || field_count)) + if (implicit_grouping) { my_message(ER_WRONG_SUM_SELECT,ER(ER_WRONG_SUM_SELECT),MYF(0)); goto err; @@ -891,15 +907,23 @@ JOIN::optimize() } #endif - /* Optimize count(*), min() and max() */ - if (tables_list && tmp_table_param.sum_func_count && ! group_list) + /* + Try to optimize count(*), min() and max() to const fields if + there is implicit grouping (aggregate functions but no + group_list). In this case, the result set shall only contain one + row. + */ + if (tables_list && implicit_grouping) { int res; /* opt_sum_query() returns HA_ERR_KEY_NOT_FOUND if no rows match to the WHERE conditions, - or 1 if all items were resolved, + or 1 if all items were resolved (optimized away), or 0, or an error number HA_ERR_... + + If all items were resolved by opt_sum_query, there is no need to + open any tables. */ if ((res=opt_sum_query(select_lex->leaf_tables, all_fields, conds))) { @@ -968,6 +992,12 @@ JOIN::optimize() DBUG_RETURN(1); } + if (select_lex->olap == ROLLUP_TYPE && rollup_process_const_fields()) + { + DBUG_PRINT("error", ("Error: rollup_process_fields() failed")); + DBUG_RETURN(1); + } + /* Remove distinct if only const tables */ select_distinct= select_distinct && (const_tables != tables); thd_proc_info(thd, "preparing"); @@ -1098,7 +1128,7 @@ JOIN::optimize() join_tab[const_tables].select->quick->get_type() != QUICK_SELECT_I::QS_TYPE_GROUP_MIN_MAX)) { - if (group_list && + if (group_list && rollup.state == ROLLUP::STATE_NONE && list_contains_unique_index(join_tab[const_tables].table, find_field_in_order_list, (void *) group_list)) @@ -1142,7 +1172,8 @@ JOIN::optimize() if (! hidden_group_fields && rollup.state == ROLLUP::STATE_NONE) select_distinct=0; } - else if (select_distinct && tables - const_tables == 1) + else if (select_distinct && tables - const_tables == 1 && + rollup.state == ROLLUP::STATE_NONE) { /* We are only using one table. In this case we change DISTINCT to a @@ -1241,13 +1272,22 @@ JOIN::optimize() (!group_list && tmp_table_param.sum_func_count)) order=0; - // Can't use sort on head table if using row cache + // Can't use sort on head table if using join buffering if (full_join) { - if (group_list) - simple_group=0; - if (order) - simple_order=0; + TABLE *stable= (sort_by_table == (TABLE *) 1 ? + join_tab[const_tables].table : sort_by_table); + /* + FORCE INDEX FOR ORDER BY can be used to prevent join buffering when + sorting on the first table. + */ + if (!stable || !stable->force_index_order) + { + if (group_list) + simple_group= 0; + if (order) + simple_order= 0; + } } /* @@ -1533,12 +1573,8 @@ JOIN::optimize() } } - /* - If this join belongs to an uncacheable subquery save - the original join - */ - if (select_lex->uncacheable && !is_top_level_join() && - init_save_join_tab()) + /* If this join belongs to an uncacheable query save the original join */ + if (select_lex->uncacheable && init_save_join_tab()) DBUG_RETURN(-1); /* purecov: inspected */ } @@ -2039,7 +2075,8 @@ JOIN::exec() count_field_types(select_lex, &curr_join->tmp_table_param, *curr_all_fields, 0); - if (curr_join->group || curr_join->tmp_table_param.sum_func_count || + if (curr_join->group || curr_join->implicit_grouping || + curr_join->tmp_table_param.sum_func_count || (procedure && (procedure->flags & PROC_GROUP))) { if (make_group_fields(this, curr_join)) @@ -2274,7 +2311,7 @@ JOIN::destroy() tab->cleanup(); } tmp_join->tmp_join= 0; - tmp_table_param.copy_field=0; + tmp_table_param.copy_field= 0; DBUG_RETURN(tmp_join->destroy()); } cond_equal= 0; @@ -3379,12 +3416,12 @@ add_key_equal_fields(KEY_FIELD **key_fields, uint and_level, @retval FALSE it's something else */ -inline static bool +static bool is_local_field (Item *field) { - field= field->real_item(); - return field->type() == Item::FIELD_ITEM && - !((Item_field *)field)->depended_from; + return field->real_item()->type() == Item::FIELD_ITEM + && !(field->used_tables() & OUTER_REF_TABLE_BIT) + && !((Item_field *)field->real_item())->depended_from; } @@ -3629,7 +3666,7 @@ add_key_part(DYNAMIC_ARRAY *keyuse_array,KEY_FIELD *key_field) { if (!(form->keys_in_use_for_query.is_set(key))) continue; - if (form->key_info[key].flags & HA_FULLTEXT) + if (form->key_info[key].flags & (HA_FULLTEXT | HA_SPATIAL)) continue; // ToDo: ft-keys in non-ft queries. SerG uint key_parts= (uint) form->key_info[key].key_parts; @@ -5677,7 +5714,9 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j, KEYUSE *org_keyuse, } j->ref.key_buff2=j->ref.key_buff+ALIGN_SIZE(length); j->ref.key_err=1; + j->ref.has_record= FALSE; j->ref.null_rejecting= 0; + j->ref.use_count= 0; keyuse=org_keyuse; store_key **ref_key= j->ref.key_copy; @@ -6511,6 +6550,20 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond) DBUG_RETURN(0); } + +/** + The default implementation of unlock-row method of READ_RECORD, + used in all access methods. +*/ + +void rr_unlock_row(st_join_table *tab) +{ + READ_RECORD *info= &tab->read_record; + info->file->unlock_row(); +} + + + static void make_join_readinfo(JOIN *join, ulonglong options) { @@ -6526,6 +6579,7 @@ make_join_readinfo(JOIN *join, ulonglong options) TABLE *table=tab->table; tab->read_record.table= table; tab->read_record.file=table->file; + tab->read_record.unlock_row= rr_unlock_row; tab->next_select=sub_select; /* normal select */ /* @@ -6571,6 +6625,7 @@ make_join_readinfo(JOIN *join, ulonglong options) delete tab->quick; tab->quick=0; tab->read_first_record= join_read_key; + tab->read_record.unlock_row= join_read_key_unlock_row; tab->read_record.read_record= join_no_more_records; if (table->covering_keys.is_set(tab->ref.key) && !table->no_keyread) @@ -9046,7 +9101,10 @@ static void restore_prev_nj_state(JOIN_TAB *last) join->cur_embedding_map&= ~last_emb->nested_join->nj_map; else if (last_emb->nested_join->n_tables-1 == last_emb->nested_join->counter) + { join->cur_embedding_map|= last_emb->nested_join->nj_map; + break; + } else break; last_emb= last_emb->embedding; @@ -9493,8 +9551,47 @@ static Field *create_tmp_field_from_item(THD *thd, Item *item, TABLE *table, new_field->set_derivation(item->collation.derivation); break; case DECIMAL_RESULT: - new_field= Field_new_decimal::new_decimal_field(item); + { + uint8 dec= item->decimals; + uint8 intg= ((Item_decimal *) item)->decimal_precision() - dec; + uint32 len= item->max_length; + + /* + Trying to put too many digits overall in a DECIMAL(prec,dec) + will always throw a warning. We must limit dec to + DECIMAL_MAX_SCALE however to prevent an assert() later. + */ + + if (dec > 0) + { + signed int overflow; + + dec= min(dec, DECIMAL_MAX_SCALE); + + /* + If the value still overflows the field with the corrected dec, + we'll throw out decimals rather than integers. This is still + bad and of course throws a truncation warning. + +1: for decimal point + */ + + const int required_length= + my_decimal_precision_to_length(intg + dec, dec, + item->unsigned_flag); + + overflow= required_length - len; + + if (overflow > 0) + dec= max(0, dec - overflow); // too long, discard fract + else + /* Corrected value fits. */ + len= required_length; + } + + new_field= new Field_new_decimal(len, maybe_null, item->name, + dec, item->unsigned_flag); break; + } case ROW_RESULT: default: // This case should never be choosen @@ -10303,6 +10400,7 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields, for (; cur_group ; cur_group= cur_group->next, key_part_info++) { Field *field=(*cur_group->item)->get_tmp_table_field(); + DBUG_ASSERT(field->table == table); bool maybe_null=(*cur_group->item)->maybe_null; key_part_info->null_bit=0; key_part_info->field= field; @@ -11062,6 +11160,12 @@ Next_select_func setup_end_select_func(JOIN *join) } else { + /* + Choose method for presenting result to user. Use end_send_group + if the query requires grouping (has a GROUP BY clause and/or one or + more aggregate functions). Use end_send if the query should not + be grouped. + */ if ((join->sort_and_group || (join->procedure && join->procedure->flags & PROC_GROUP)) && !tmp_tbl->precomputed_group_by) @@ -11430,6 +11534,7 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab, bool not_used_in_distinct=join_tab->not_used_in_distinct; ha_rows found_records=join->found_records; COND *select_cond= join_tab->select_cond; + bool select_cond_result= TRUE; if (error > 0 || (join->thd->is_error())) // Fatal error return NESTED_LOOP_ERROR; @@ -11441,7 +11546,17 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab, return NESTED_LOOP_KILLED; /* purecov: inspected */ } DBUG_PRINT("info", ("select cond 0x%lx", (ulong)select_cond)); - if (!select_cond || select_cond->val_int()) + + if (select_cond) + { + select_cond_result= test(select_cond->val_int()); + + /* check for errors evaluating the condition */ + if (join->thd->is_error()) + return NESTED_LOOP_ERROR; + } + + if (!select_cond || select_cond_result) { /* There is no select condition or the attached pushed down @@ -11525,7 +11640,7 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab, return NESTED_LOOP_NO_MORE_ROWS; } else - join_tab->read_record.file->unlock_row(); + join_tab->read_record.unlock_row(join_tab); } else { @@ -11535,7 +11650,7 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab, */ join->examined_rows++; join->thd->row_count++; - join_tab->read_record.file->unlock_row(); + join_tab->read_record.unlock_row(join_tab); } return NESTED_LOOP_OK; } @@ -11915,18 +12030,55 @@ join_read_key(JOIN_TAB *tab) table->status=STATUS_NOT_FOUND; return -1; } + /* + Moving away from the current record. Unlock the row + in the handler if it did not match the partial WHERE. + */ + if (tab->ref.has_record && tab->ref.use_count == 0) + { + tab->read_record.file->unlock_row(); + tab->ref.has_record= FALSE; + } error=table->file->index_read_map(table->record[0], tab->ref.key_buff, make_prev_keypart_map(tab->ref.key_parts), HA_READ_KEY_EXACT); if (error && error != HA_ERR_KEY_NOT_FOUND && error != HA_ERR_END_OF_FILE) return report_error(table, error); + + if (! error) + { + tab->ref.has_record= TRUE; + tab->ref.use_count= 1; + } + } + else if (table->status == 0) + { + DBUG_ASSERT(tab->ref.has_record); + tab->ref.use_count++; } table->null_row=0; return table->status ? -1 : 0; } +/** + Since join_read_key may buffer a record, do not unlock + it if it was not used in this invocation of join_read_key(). + Only count locks, thus remembering if the record was left unused, + and unlock already when pruning the current value of + TABLE_REF buffer. + @sa join_read_key() +*/ + +static void +join_read_key_unlock_row(st_join_table *tab) +{ + DBUG_ASSERT(tab->ref.use_count); + if (tab->ref.use_count) + tab->ref.use_count--; +} + /* ref access method implementation: "read_first" function @@ -13994,7 +14146,10 @@ static int remove_dup_with_compare(THD *thd, TABLE *table, Field **first_field, if (error) { if (error == HA_ERR_RECORD_DELETED) - continue; + { + error= file->rnd_next(record); + continue; + } if (error == HA_ERR_END_OF_FILE) break; goto err; @@ -15923,32 +16078,7 @@ bool JOIN::rollup_init() { item->maybe_null= 1; found_in_group= 1; - if (item->const_item()) - { - /* - For ROLLUP queries each constant item referenced in GROUP BY list - is wrapped up into an Item_func object yielding the same value - as the constant item. The objects of the wrapper class are never - considered as constant items and besides they inherit all - properties of the Item_result_field class. - This wrapping allows us to ensure writing constant items - into temporary tables whenever the result of the ROLLUP - operation has to be written into a temporary table, e.g. when - ROLLUP is used together with DISTINCT in the SELECT list. - Usually when creating temporary tables for a intermidiate - result we do not include fields for constant expressions. - */ - Item* new_item= new Item_func_rollup_const(item); - if (!new_item) - return 1; - new_item->fix_fields(thd, (Item **) 0); - thd->change_item_tree(it.ref(), new_item); - for (ORDER *tmp= group_tmp; tmp; tmp= tmp->next) - { - if (*tmp->item == item) - thd->change_item_tree(tmp->item, new_item); - } - } + break; } } if (item->type() == Item::FUNC_ITEM && !found_in_group) @@ -15967,6 +16097,59 @@ bool JOIN::rollup_init() } return 0; } + +/** + Wrap all constant Items in GROUP BY list. + + For ROLLUP queries each constant item referenced in GROUP BY list + is wrapped up into an Item_func object yielding the same value + as the constant item. The objects of the wrapper class are never + considered as constant items and besides they inherit all + properties of the Item_result_field class. + This wrapping allows us to ensure writing constant items + into temporary tables whenever the result of the ROLLUP + operation has to be written into a temporary table, e.g. when + ROLLUP is used together with DISTINCT in the SELECT list. + Usually when creating temporary tables for a intermidiate + result we do not include fields for constant expressions. + + @retval + 0 if ok + @retval + 1 on error +*/ + +bool JOIN::rollup_process_const_fields() +{ + ORDER *group_tmp; + Item *item; + List_iterator<Item> it(all_fields); + + for (group_tmp= group_list; group_tmp; group_tmp= group_tmp->next) + { + if (!(*group_tmp->item)->const_item()) + continue; + while ((item= it++)) + { + if (*group_tmp->item == item) + { + Item* new_item= new Item_func_rollup_const(item); + if (!new_item) + return 1; + new_item->fix_fields(thd, (Item **) 0); + thd->change_item_tree(it.ref(), new_item); + for (ORDER *tmp= group_tmp; tmp; tmp= tmp->next) + { + if (*tmp->item == item) + thd->change_item_tree(tmp->item, new_item); + } + break; + } + } + it.rewind(); + } + return 0; +} /** |