diff options
Diffstat (limited to 'sql/ha_partition.cc')
| -rw-r--r-- | sql/ha_partition.cc | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc index ed2cb96a115..9e07ea7258f 100644 --- a/sql/ha_partition.cc +++ b/sql/ha_partition.cc @@ -4220,6 +4220,58 @@ int ha_partition::index_read_last_map(uchar *buf, const uchar *key, /* + Optimization of the default implementation to take advantage of dynamic + partition pruning. +*/ +int ha_partition::index_read_idx_map(uchar *buf, uint index, + const uchar *key, + key_part_map keypart_map, + enum ha_rkey_function find_flag) +{ + int error= HA_ERR_KEY_NOT_FOUND; + DBUG_ENTER("ha_partition::index_read_idx_map"); + + if (find_flag == HA_READ_KEY_EXACT) + { + uint part; + m_start_key.key= key; + m_start_key.keypart_map= keypart_map; + m_start_key.flag= find_flag; + m_start_key.length= calculate_key_len(table, index, m_start_key.key, + m_start_key.keypart_map); + + get_partition_set(table, buf, index, &m_start_key, &m_part_spec); + + /* How can it be more than one partition with the current use? */ + DBUG_ASSERT(m_part_spec.start_part == m_part_spec.end_part); + + for (part= m_part_spec.start_part; part <= m_part_spec.end_part; part++) + { + if (bitmap_is_set(&(m_part_info->used_partitions), part)) + { + error= m_file[part]->index_read_idx_map(buf, index, key, + keypart_map, find_flag); + if (error != HA_ERR_KEY_NOT_FOUND && + error != HA_ERR_END_OF_FILE) + break; + } + } + } + else + { + /* + If not only used with READ_EXACT, we should investigate if possible + to optimize for other find_flag's as well. + */ + DBUG_ASSERT(0); + /* fall back on the default implementation */ + error= handler::index_read_idx_map(buf, index, key, keypart_map, find_flag); + } + DBUG_RETURN(error); +} + + +/* Read next record in a forward index scan SYNOPSIS |