Hi, Alexey! On Dec 04, Alexey Botchkov wrote:

revision-id: 0f4717118e135c178fc1b12065e33ac8a5e21d0b (mariadb-10.3.2-82-g0f47171) parent(s): ddac2d7a1ef725361c7e83b819cb0bec72db024a committer: Alexey Botchkov timestamp: 2017-12-04 17:45:13 +0400 message:

MDEV-14005 Remove need for Partition Key to be part of Primary Key.

Now we check all partitions for the unique keys if necessary in ha_partition::write_row and ha_partition::update_row.

diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc index 6bebf5d..12a6287 100644 --- a/sql/ha_partition.cc +++ b/sql/ha_partition.cc @@ -372,6 +372,7 @@ void ha_partition::init_handler_variables() part_share= NULL; m_new_partitions_share_refs.empty(); m_part_ids_sorted_by_num_of_records= NULL; + m_cu_errkey= (uint) -1;

#ifdef DONT_HAVE_TO_BE_INITALIZED m_start_key.flag= 0; @@ -4088,6 +4089,79 @@ void ha_partition::try_semi_consistent_read(bool yes) }

+int ha_partition::check_files_for_key(uchar *key, int n_key, + int partition_to_skip, int *res) +{ +// uint num_subparts= part_info->num_subparts; + for (uint n=0; n < m_part_info->num_parts; n++) + { + handler *f= m_file[n]; + int ires; + + if ((int) n == partition_to_skip) + continue; + + f->active_index= n_key; + if ((*res= f->extra(HA_EXTRA_KEYREAD)) || + (*res= f->ha_index_init(n_key, FALSE))) + return 1; + + *res= f->index_read_map(m_part_info->table->record[0], + key, HA_WHOLE_KEY, HA_READ_KEY_EXACT);

use index_read_idx_map here

+ ires= f->ha_index_end(); + + if (*res == HA_ERR_KEY_NOT_FOUND) + continue; + + if (*res == 0) + *res= ires ? ires : HA_ERR_FOUND_DUPP_KEY; + + m_last_part= n; + m_cu_errkey= n_key; + return 1; + } + + *res= 0; + return 0; +} + + +int ha_partition::check_uniques_insert(uchar *buf, + int partition_to_skip, int *res) +{ + uint n_key; + + for (n_key=0; n_key < m_part_info->n_uniques_to_check; n_key++) + {

can you use key_copy() here?

+ uchar *cbuf= m_part_info->unique_key_buf[0]; + KEY *ckey= m_part_info->uniques_to_check[n_key]; + uint n; + + for (n=0; n < ckey->user_defined_key_parts; n++) + { + const KEY_PART_INFO *cpart= ckey->key_part + n; + uint maybe_null= MY_TEST(cpart->null_bit); + Field *f= cpart->field; + my_ptrdiff_t ofs= buf-table->record[0]; + + f->move_field_offset(ofs); + if (maybe_null) + cbuf[0]= f->is_null(); + f->get_key_image(cbuf+maybe_null, cpart->length, Field::itRAW); + cbuf+= cpart->store_length; + f->move_field_offset(-ofs); + } + + if (check_files_for_key(m_part_info->unique_key_buf[0], n_key, + partition_to_skip, res)) + return 1; + } + + *res= 0; + return 0; +} + + /**************************************************************************** MODULE change record ****************************************************************************/ @@ -4199,6 +4273,11 @@ int ha_partition::write_row(uchar * buf) error= HA_ERR_NOT_IN_LOCK_PARTITIONS; goto exit; } + + if (table->part_info->n_uniques_to_check && + check_uniques_insert(buf, part_id, &error)) + goto exit;

This would _probably_ introduce the race condition I've mentioned in a comment to MDEV-14005. Say, you have a table with two partitions and a unique key. Now, two threads try to insert rows, the first thread inserts 1 into the first partition (there are more columns in a table and a partitioning key on those columns, but I omit these details for simplicity). And a second thread inserts 1 into the second partition. So, the first thread checks for 1 in the second partition, finds nothing. Second thread checks for 1 in the first partition, finds nothing. Then the first thread inserts 1 into the first partition, second thread inserts 1 into the second partition. Monty's idea was to insert optimistically - first you insert, then check for duplicates. Not ideal, in the above example you can have both threads getting a duplicate key error. There could be other, e.g. locking, solutions too.

m_last_part= part_id; DBUG_PRINT("info", ("Insert in partition %d", part_id)); start_part_bulk_insert(thd, part_id);

Regards, Sergei Chief Architect MariaDB and security@mariadb.org