On 29.09.2017 04:33, Amit Langote wrote:
So, we should be looking at partconstraintdef only when verbose is true,
because that's only when we set it to a valid value. Now, if
partconstraintdef is NULL even after verbose is true, that means backend
returned that there exists no constraint for that partition, which I
thought would be true for a default partition (because the commit that
introduced default partitions also introduced "No partition constraint"),
but it's really not.
For example, \d and \d+ show contradictory outputs for a default partition.
create table p (a int) partition by list (a);
create table p1 partition of p for values in (1);
create table pd partition of p default;
\d pd
Table "public.pd"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+---------
a | integer | | |
Partition of: p DEFAULT
No partition constraint
\d+ pd
Table "public.pd"
Column | Type | Collation | Nullable | Default | Storage | Stats
target | Description
--------+---------+-----------+----------+---------+---------+--------------+-------------
a | integer | | | | plain | |
Partition of: p DEFAULT
Partition constraint: (NOT ((a IS NOT NULL) AND (a = ANY (ARRAY[1]))))
Perhaps, there is no case when "No partition constraint" should be output,
but I may be missing something.
Anyhow, we have to protect ourselves from empty output from
*pg_get_partition_constraintdef*. And printing *No partition constraint*
would be good point to start to examine why we didn't get any constraint
definition.
--
Regards,
Maksim Milyutin