diff options
Diffstat (limited to 'sql/opt_range.cc')
| -rw-r--r-- | sql/opt_range.cc | 85 |
1 files changed, 54 insertions, 31 deletions
diff --git a/sql/opt_range.cc b/sql/opt_range.cc index 8629ea57fb9..1de603193c4 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -112,7 +112,7 @@ #include "key.h" // is_key_used, key_copy, key_cmp, key_restore #include "sql_parse.h" // check_stack_overrun #include "sql_partition.h" // get_part_id_func, PARTITION_ITERATOR, - // struct partition_info + // struct partition_info, NOT_A_PARTITION_ID #include "sql_base.h" // free_io_cache #include "records.h" // init_read_record, end_read_record #include <m_ctype.h> @@ -3386,29 +3386,26 @@ static void dbug_print_singlepoint_range(SEL_ARG **start, uint num); #endif -/* +/** Perform partition pruning for a given table and condition. - SYNOPSIS - prune_partitions() - thd Thread handle - table Table to perform partition pruning for - pprune_cond Condition to use for partition pruning + @param thd Thread handle + @param table Table to perform partition pruning for + @param pprune_cond Condition to use for partition pruning - DESCRIPTION - This function assumes that all partitions are marked as unused when it - is invoked. The function analyzes the condition, finds partitions that - need to be used to retrieve the records that match the condition, and - marks them as used by setting appropriate bit in part_info->used_partitions - In the worst case all partitions are marked as used. - - NOTE - This function returns promptly if called for non-partitioned table. - - RETURN - TRUE We've inferred that no partitions need to be used (i.e. no table - records will satisfy pprune_cond) - FALSE Otherwise + @note This function assumes that lock_partitions are setup when it + is invoked. The function analyzes the condition, finds partitions that + need to be used to retrieve the records that match the condition, and + marks them as used by setting appropriate bit in part_info->read_partitions + In the worst case all partitions are marked as used. If the table is not + yet locked, it will also unset bits in part_info->lock_partitions that is + not set in read_partitions. + + This function returns promptly if called for non-partitioned table. + + @return Operation status + @retval true Failure + @retval false Success */ bool prune_partitions(THD *thd, TABLE *table, Item *pprune_cond) @@ -3461,7 +3458,7 @@ bool prune_partitions(THD *thd, TABLE *table, Item *pprune_cond) thd->no_errors=1; // Don't warn about NULL thd->mem_root=&alloc; - bitmap_clear_all(&part_info->used_partitions); + bitmap_clear_all(&part_info->read_partitions); prune_param.key= prune_param.range_param.key_parts; SEL_TREE *tree; @@ -3545,6 +3542,30 @@ end: thd->mem_root= range_par->old_root; free_root(&alloc,MYF(0)); // Return memory & allocator DBUG_RETURN(retval); + /* + Must be a subset of the locked partitions. + lock_partitions contains the partitions marked by explicit partition + selection (... t PARTITION (pX) ...) and we must only use partitions + within that set. + */ + bitmap_intersect(&prune_param.part_info->read_partitions, + &prune_param.part_info->lock_partitions); + /* + If not yet locked, also prune partitions to lock if not UPDATEing + partition key fields. This will also prune lock_partitions if we are under + LOCK TABLES, so prune away calls to start_stmt(). + TODO: enhance this prune locking to also allow pruning of + 'UPDATE t SET part_key = const WHERE cond_is_prunable' so it adds + a lock for part_key partition. + */ + if (!thd->lex->is_query_tables_locked() && + !partition_key_modified(table, table->write_set)) + { + bitmap_copy(&prune_param.part_info->lock_partitions, + &prune_param.part_info->read_partitions); + } + if (bitmap_is_clear_all(&(prune_param.part_info->read_partitions))) + table->all_partitions_pruned_away= true; } @@ -3619,7 +3640,7 @@ static void mark_full_partition_used_no_parts(partition_info* part_info, { DBUG_ENTER("mark_full_partition_used_no_parts"); DBUG_PRINT("enter", ("Mark partition %u as used", part_id)); - bitmap_set_bit(&part_info->used_partitions, part_id); + bitmap_set_bit(&part_info->read_partitions, part_id); DBUG_VOID_RETURN; } @@ -3635,7 +3656,7 @@ static void mark_full_partition_used_with_parts(partition_info *part_info, for (; start != end; start++) { DBUG_PRINT("info", ("1:Mark subpartition %u as used", start)); - bitmap_set_bit(&part_info->used_partitions, start); + bitmap_set_bit(&part_info->read_partitions, start); } DBUG_VOID_RETURN; } @@ -3663,7 +3684,7 @@ static int find_used_partitions_imerge_list(PART_PRUNE_PARAM *ppar, MY_BITMAP all_merges; uint bitmap_bytes; my_bitmap_map *bitmap_buf; - uint n_bits= ppar->part_info->used_partitions.n_bits; + uint n_bits= ppar->part_info->read_partitions.n_bits; bitmap_bytes= bitmap_buffer_size(n_bits); if (!(bitmap_buf= (my_bitmap_map*) alloc_root(ppar->range_param.mem_root, bitmap_bytes))) @@ -3689,14 +3710,15 @@ static int find_used_partitions_imerge_list(PART_PRUNE_PARAM *ppar, } if (res != -1) - bitmap_intersect(&all_merges, &ppar->part_info->used_partitions); + bitmap_intersect(&all_merges, &ppar->part_info->read_partitions); + if (bitmap_is_clear_all(&all_merges)) return 0; - bitmap_clear_all(&ppar->part_info->used_partitions); + bitmap_clear_all(&ppar->part_info->read_partitions); } - memcpy(ppar->part_info->used_partitions.bitmap, all_merges.bitmap, + memcpy(ppar->part_info->read_partitions.bitmap, all_merges.bitmap, bitmap_bytes); return 1; } @@ -4056,7 +4078,7 @@ int find_used_partitions(PART_PRUNE_PARAM *ppar, SEL_ARG *key_tree) { for (uint i= 0; i < ppar->part_info->num_subparts; i++) if (bitmap_is_set(&ppar->subparts_bitmap, i)) - bitmap_set_bit(&ppar->part_info->used_partitions, + bitmap_set_bit(&ppar->part_info->read_partitions, part_id * ppar->part_info->num_subparts + i); } goto pop_and_go_right; @@ -4118,7 +4140,7 @@ int find_used_partitions(PART_PRUNE_PARAM *ppar, SEL_ARG *key_tree) while ((part_id= ppar->part_iter.get_next(&ppar->part_iter)) != NOT_A_PARTITION_ID) { - bitmap_set_bit(&part_info->used_partitions, + bitmap_set_bit(&part_info->read_partitions, part_id * part_info->num_subparts + subpart_id); } res= 1; /* Some partitions were marked as used */ @@ -4204,7 +4226,8 @@ pop_and_go_right: static void mark_all_partitions_as_used(partition_info *part_info) { - bitmap_set_all(&part_info->used_partitions); + bitmap_copy(&(part_info->read_partitions), + &(part_info->lock_partitions)); } |