better hash algorithms for PARTITION BY KEY

[openxs@fc23 maria10.1]$ bin/mysql -uroot test

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A

Welcome to the MariaDB monitor.  Commands end with ; or \g.

Your MariaDB connection id is 3

Server version: 10.1.13-MariaDB Source distribution

Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [test]> drop table t1;

Query OK, 0 rows affected (0.18 sec)

MariaDB [test]> create table t1(c1 int, c2 date) partition by key(c2) partitions 8;

Query OK, 0 rows affected (1.92 sec)

MariaDB [test]> insert into t1 values (1, '2014-04-22');

Query OK, 1 row affected (0.04 sec)

MariaDB [test]> insert into t1 values (1, '2014-04-23');

Query OK, 1 row affected (0.04 sec)

MariaDB [test]> insert into t1 values (1, '2014-04-24');

Query OK, 1 row affected (0.04 sec)

MariaDB [test]> insert into t1 values (1, '2014-04-25');

Query OK, 1 row affected (0.04 sec)

MariaDB [test]> insert into t1 values (1, '2014-04-26');

Query OK, 1 row affected (0.15 sec)

MariaDB [test]> insert into t1 values (1, '2014-04-27');

Query OK, 1 row affected (0.05 sec)

MariaDB [test]> insert into t1 values (1, '2014-04-28');

Query OK, 1 row affected (0.04 sec)

MariaDB [test]> insert into t1 values (1, '2014-04-29');

Query OK, 1 row affected (0.12 sec)

MariaDB [test]> insert into t1 values (1, '2014-04-30');

Query OK, 1 row affected (0.07 sec)

MariaDB [test]> select partition_name, table_rows from information_schema.partitions where table_name='t1';

+----------------+------------+

| partition_name | table_rows |

+----------------+------------+

| p0             |          3 |

| p1             |          0 |

| p2             |          0 |

| p3             |          0 |

| p4             |          2 |

| p5             |          0 |

| p6             |          4 |

| p7             |          0 |

+----------------+------------+

8 rows in set (0.00 sec)

MariaDB [test]>

--source include/have_sequence.inc

create table t1(c1 int, c2 date) partition by key  (c2) partitions 8;

insert into t1 select 1, from_days(seq) from seq_735000_to_736000;

select partition_name, table_rows from information_schema.partitions where table_name='t1';

partition_name	table_rows

p0	297

p1	0

p2	0

p3	0

p4	428

p5	0

p6	276

p7	0

drop table t1;

To determine which partition to use, the following calculation is performed:\

MOD(partitioning\_expression, number\_of\_partitions)