diff options
Diffstat (limited to 'sql/opt_range.cc')
| -rw-r--r-- | sql/opt_range.cc | 93 |
1 files changed, 33 insertions, 60 deletions
diff --git a/sql/opt_range.cc b/sql/opt_range.cc index a46bfcf2d0e..5e985625c78 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -8717,8 +8717,6 @@ int QUICK_RANGE_SELECT::get_next() { int result; KEY_MULTI_RANGE *mrange; - key_range *start_key; - key_range *end_key; DBUG_ENTER("QUICK_RANGE_SELECT::get_next"); DBUG_ASSERT(multi_range_length && multi_range && (cur_range >= (QUICK_RANGE**) ranges.buffer) && @@ -8758,26 +8756,9 @@ int QUICK_RANGE_SELECT::get_next() mrange_slot < mrange_end; mrange_slot++) { - start_key= &mrange_slot->start_key; - end_key= &mrange_slot->end_key; last_range= *(cur_range++); - - start_key->key= (const uchar*) last_range->min_key; - start_key->length= last_range->min_length; - start_key->flag= ((last_range->flag & NEAR_MIN) ? HA_READ_AFTER_KEY : - (last_range->flag & EQ_RANGE) ? - HA_READ_KEY_EXACT : HA_READ_KEY_OR_NEXT); - start_key->keypart_map= last_range->min_keypart_map; - end_key->key= (const uchar*) last_range->max_key; - end_key->length= last_range->max_length; - /* - We use HA_READ_AFTER_KEY here because if we are reading on a key - prefix. We want to find all keys with this prefix. - */ - end_key->flag= (last_range->flag & NEAR_MAX ? HA_READ_BEFORE_KEY : - HA_READ_AFTER_KEY); - end_key->keypart_map= last_range->max_keypart_map; - + last_range->make_min_endpoint(&mrange_slot->start_key); + last_range->make_max_endpoint(&mrange_slot->end_key); mrange_slot->range_flag= last_range->flag; } @@ -8801,49 +8782,52 @@ end: /* Get the next record with a different prefix. - SYNOPSIS - QUICK_RANGE_SELECT::get_next_prefix() - prefix_length length of cur_prefix - cur_prefix prefix of a key to be searched for + @param prefix_length length of cur_prefix + @param group_key_parts The number of key parts in the group prefix + @param cur_prefix prefix of a key to be searched for - DESCRIPTION - Each subsequent call to the method retrieves the first record that has a - prefix with length prefix_length different from cur_prefix, such that the - record with the new prefix is within the ranges described by - this->ranges. The record found is stored into the buffer pointed by - this->record. - The method is useful for GROUP-BY queries with range conditions to - discover the prefix of the next group that satisfies the range conditions. + Each subsequent call to the method retrieves the first record that has a + prefix with length prefix_length and which is different from cur_prefix, + such that the record with the new prefix is within the ranges described by + this->ranges. The record found is stored into the buffer pointed by + this->record. The method is useful for GROUP-BY queries with range + conditions to discover the prefix of the next group that satisfies the range + conditions. + + @todo - TODO This method is a modified copy of QUICK_RANGE_SELECT::get_next(), so both methods should be unified into a more general one to reduce code duplication. - RETURN - 0 on success - HA_ERR_END_OF_FILE if returned all keys - other if some error occurred + @retval 0 on success + @retval HA_ERR_END_OF_FILE if returned all keys + @retval other if some error occurred */ int QUICK_RANGE_SELECT::get_next_prefix(uint prefix_length, - key_part_map keypart_map, + uint group_key_parts, uchar *cur_prefix) { DBUG_ENTER("QUICK_RANGE_SELECT::get_next_prefix"); + const key_part_map keypart_map= make_prev_keypart_map(group_key_parts); for (;;) { int result; - key_range start_key, end_key; if (last_range) { /* Read the next record in the same range with prefix after cur_prefix. */ - DBUG_ASSERT(cur_prefix != 0); + DBUG_ASSERT(cur_prefix != NULL); result= file->index_read_map(record, cur_prefix, keypart_map, HA_READ_AFTER_KEY); - if (result || (file->compare_key(file->end_range) <= 0)) + if (result || last_range->max_keypart_map == 0) DBUG_RETURN(result); + + key_range previous_endpoint; + last_range->make_max_endpoint(&previous_endpoint, prefix_length, keypart_map); + if (file->compare_key(&previous_endpoint) <= 0) + DBUG_RETURN(0); } uint count= ranges.elements - (cur_range - (QUICK_RANGE**) ranges.buffer); @@ -8855,21 +8839,9 @@ int QUICK_RANGE_SELECT::get_next_prefix(uint prefix_length, } last_range= *(cur_range++); - start_key.key= (const uchar*) last_range->min_key; - start_key.length= min(last_range->min_length, prefix_length); - start_key.keypart_map= last_range->min_keypart_map & keypart_map; - start_key.flag= ((last_range->flag & NEAR_MIN) ? HA_READ_AFTER_KEY : - (last_range->flag & EQ_RANGE) ? - HA_READ_KEY_EXACT : HA_READ_KEY_OR_NEXT); - end_key.key= (const uchar*) last_range->max_key; - end_key.length= min(last_range->max_length, prefix_length); - end_key.keypart_map= last_range->max_keypart_map & keypart_map; - /* - We use READ_AFTER_KEY here because if we are reading on a key - prefix we want to find all keys with this prefix - */ - end_key.flag= (last_range->flag & NEAR_MAX ? HA_READ_BEFORE_KEY : - HA_READ_AFTER_KEY); + key_range start_key, end_key; + last_range->make_min_endpoint(&start_key, prefix_length, keypart_map); + last_range->make_max_endpoint(&end_key, prefix_length, keypart_map); result= file->read_range_first(last_range->min_keypart_map ? &start_key : 0, last_range->max_keypart_map ? &end_key : 0, @@ -8964,9 +8936,9 @@ bool QUICK_RANGE_SELECT::row_in_ranges() } /* - This is a hack: we inherit from QUICK_SELECT so that we can use the + This is a hack: we inherit from QUICK_RANGE_SELECT so that we can use the get_next() interface, but we have to hold a pointer to the original - QUICK_SELECT because its data are used all over the place. What + QUICK_RANGE_SELECT because its data are used all over the place. What should be done is to factor out the data that is needed into a base class (QUICK_SELECT), and then have two subclasses (_ASC and _DESC) which handle the ranges and implement the get_next() function. But @@ -11159,7 +11131,8 @@ int QUICK_GROUP_MIN_MAX_SELECT::next_prefix() { uchar *cur_prefix= seen_first_key ? group_prefix : NULL; if ((result= quick_prefix_select->get_next_prefix(group_prefix_len, - make_prev_keypart_map(group_key_parts), cur_prefix))) + group_key_parts, + cur_prefix))) DBUG_RETURN(result); seen_first_key= TRUE; } |