diff options
Diffstat (limited to 'sql/opt_range.cc')
| -rw-r--r-- | sql/opt_range.cc | 67 |
1 files changed, 38 insertions, 29 deletions
diff --git a/sql/opt_range.cc b/sql/opt_range.cc index 5a0c4066ae0..fa27ef43463 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -274,7 +274,11 @@ class SEL_TREE :public Sql_alloc public: enum Type { IMPOSSIBLE, ALWAYS, MAYBE, KEY, KEY_SMALLER } type; SEL_TREE(enum Type type_arg) :type(type_arg) {} - SEL_TREE() :type(KEY) { keys_map.clear_all(); bzero((char*) keys,sizeof(keys));} + SEL_TREE() :type(KEY) + { + keys_map.clear_all(); + bzero((char*) keys,sizeof(keys)); + } SEL_ARG *keys[MAX_KEY]; key_map keys_map; /* bitmask of non-NULL elements in keys */ List<SEL_IMERGE> merges; /* possible ways to read rows using index_merge */ @@ -306,7 +310,8 @@ static ha_rows check_quick_keys(PARAM *param,uint index,SEL_ARG *key_tree, char *max_key, uint max_key_flag); QUICK_RANGE_SELECT *get_quick_select(PARAM *param,uint index, - SEL_ARG *key_tree, MEM_ROOT *alloc = NULL); + SEL_ARG *key_tree, + MEM_ROOT *alloc = NULL); static int get_quick_select_params(SEL_TREE *tree, PARAM *param, key_map& needed_reg, bool index_read_can_be_used, @@ -338,7 +343,8 @@ bool get_quick_keys(PARAM *param,QUICK_RANGE_SELECT *quick,KEY_PART *key, static bool eq_tree(SEL_ARG* a,SEL_ARG *b); static SEL_ARG null_element(SEL_ARG::IMPOSSIBLE); -static bool null_part_in_key(KEY_PART *key_part, const char *key, uint length); +static bool null_part_in_key(KEY_PART *key_part, const char *key, + uint length); bool sel_trees_can_be_ored(SEL_TREE *tree1, SEL_TREE *tree2, PARAM* param); @@ -620,7 +626,7 @@ QUICK_SELECT_I::QUICK_SELECT_I() QUICK_RANGE_SELECT::QUICK_RANGE_SELECT(THD *thd, TABLE *table, uint key_nr, bool no_alloc, MEM_ROOT *parent_alloc) - :dont_free(0),error(0),range(0),cur_range(NULL) + :dont_free(0),error(0),cur_range(NULL),range(0) { index= key_nr; head= table; @@ -654,9 +660,10 @@ QUICK_RANGE_SELECT::~QUICK_RANGE_SELECT() } -QUICK_INDEX_MERGE_SELECT::QUICK_INDEX_MERGE_SELECT(THD *thd_param, TABLE *table) - :cur_quick_it(quick_selects), thd(thd_param), unique(NULL), - pk_quick_select(NULL) +QUICK_INDEX_MERGE_SELECT::QUICK_INDEX_MERGE_SELECT(THD *thd_param, + TABLE *table) + :cur_quick_it(quick_selects),pk_quick_select(NULL),unique(NULL), + thd(thd_param) { index= MAX_KEY; head= table; @@ -1231,7 +1238,7 @@ static int get_index_merge_params(PARAM *param, key_map& needed_reg, double tree_read_time; ha_rows tree_records; bool pk_is_clustered= param->table->file->primary_key_is_clustered(); - bool have_cpk_scan; + bool have_cpk_scan= false; ha_rows records_for_unique= 0; ha_rows cpk_records= 0; @@ -1295,8 +1302,9 @@ static int get_index_merge_params(PARAM *param, key_map& needed_reg, imerge_cost += get_index_only_read_time(param, tree_records,keynr); records_for_unique += tree_records; } - } - + } + DBUG_PRINT("info",("index_merge cost of index reads: %g", imerge_cost)); + if (imerge_too_expensive) DBUG_RETURN(1); @@ -1329,33 +1337,37 @@ static int get_index_merge_params(PARAM *param, key_map& needed_reg, else { double n_blocks= - ceil((double)(longlong)param->table->file->data_file_length / IO_SIZE); - /* Don't ceil the following as it is an estimate */ + ceil((double)(longlong)param->table->file->data_file_length / IO_SIZE); double busy_blocks= n_blocks * (1.0 - pow(1.0 - 1.0/n_blocks, records_for_unique)); JOIN *join= param->thd->lex->select_lex.join; if (!join || join->tables == 1) - { imerge_cost += busy_blocks*(DISK_SEEK_BASE_COST + DISK_SEEK_PROP_COST*n_blocks/busy_blocks); - } else { /* It can be a join with source table being non-last table, so assume that disk seeks are random here. - (TODO it is possible to determine if this *is* a last table in 'index - checked for each record'-type join) + (TODO it is possible to determine if this is a last table in 'index + checked for each record' join) */ imerge_cost += busy_blocks; } } + DBUG_PRINT("info",("index_merge cost with rowid-to-row scan: %g", imerge_cost)); /* PHASE 3: Add Unique operations cost */ - imerge_cost += Unique::get_use_cost(param->mem_root, records_for_unique, - param->table->file->ref_length, - param->thd->variables.sortbuff_size); + double unique_cost= + Unique::get_use_cost(param->mem_root, records_for_unique, + param->table->file->ref_length, + param->thd->variables.sortbuff_size); + if (unique_cost < 0.0) + DBUG_RETURN(1); + + imerge_cost += unique_cost; + DBUG_PRINT("info",("index_merge total cost: %g", imerge_cost)); if (imerge_cost < *read_time) { *read_time= imerge_cost; @@ -1382,7 +1394,8 @@ static int get_index_merge_params(PARAM *param, key_map& needed_reg, key blocks are half full (normally things are much better). */ -inline double get_index_only_read_time(PARAM* param, ha_rows records, int keynr) +inline double get_index_only_read_time(PARAM* param, ha_rows records, + int keynr) { double read_time; uint keys_per_block= (param->table->file->block_size/2/ @@ -1445,18 +1458,13 @@ static int get_quick_select_params(SEL_TREE *tree, PARAM *param, read_index_only && (param->table->file->index_flags(keynr) & HA_KEY_READ_ONLY)) { - /* - We can resolve this by only reading through this key. - Assume that we will read trough the whole key range - and that all key blocks are half full (normally things are - much better). - */ + /* We can resolve this by only reading through this key. */ found_read_time=get_index_only_read_time(param, found_records, keynr); } else found_read_time= (param->table->file->read_time(keynr, - param->range_count, - found_records)+ + param->range_count, + found_records)+ (double) found_records / TIME_FOR_COMPARE); if (*read_time > found_read_time && found_records != HA_POS_ERROR) { @@ -3893,7 +3901,8 @@ static void print_quick_sel_imerge(QUICK_INDEX_MERGE_SELECT *quick, DBUG_VOID_RETURN; } -void print_quick_sel_range(QUICK_RANGE_SELECT *quick,const key_map *needed_reg) +void print_quick_sel_range(QUICK_RANGE_SELECT *quick, + const key_map *needed_reg) { QUICK_RANGE *range; char buf[MAX_KEY/8+1]; |