[#MDEV-25540] Auto-create: There is no clear way to disable auto-creation without ruining existing partitions

Note: If there is in fact a way to disable auto-partitioning, please make it a documentation request, as at the very least it is not obvious.

I have an auto-partitioned table with some already existing and populated history partitions:

bb-10.6-midenok-MDEV-17554 b96b96f9f3ec
create or replace table t1 (pk int primary key, a int) engine=MyISAM with system versioning partition by system_time limit 100 auto;
insert into t1 select seq, seq from seq_1_to_80;
replace into t1 select seq, seq from seq_1_to_80;
replace into t1 select seq, seq from seq_1_to_80;
replace into t1 select seq, seq from seq_1_to_80;
replace into t1 select seq, seq from seq_1_to_80;
replace into t1 select seq, seq from seq_1_to_80;
select partition_name, table_rows from information_schema.partitions where table_name = 't1';
+----------------+------------+
\| partition_name \| table_rows \|
+----------------+------------+
\| p0 \| 160 \|
\| p1 \| 160 \|
\| p2 \| 80 \|
\| pn \| 80 \|
+----------------+------------+

Now I just want to disable further auto-partitioning.
What I tried was:

alter table t1 partition by system_time limit 100;

but it reorganizes existing partitions into 1+1:

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

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

| partition_name | table_rows |

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

| p0             |        400 |

| pn             |         80 |

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

2 rows in set (0.003 sec)

or (back from the original structure with 3+1 partitions):

alter table t1 partition by system_time limit 100 partitions 4;

but it still reorganizes partitions and puts everything into the first one:

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

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

| partition_name | table_rows |

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

| p0             |        400 |

| p1             |          0 |

| p2             |          0 |

| pn             |         80 |

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

(maybe tried something else, but to no avail).

[MDEV-25540] Auto-create: There is no clear way to disable auto-creation without ruining existing partitions Created: 2021-04-27 Updated: 2022-01-12 Resolved: 2022-01-12
Status:	Closed
Project:	MariaDB Server
Component/s:	Partitioning, Versioned Tables
Affects Version/s:	10.8
Fix Version/s:	N/A