Hi, Junwang Zhao!
Thank you for note.
1.
>Would it be better to use RELATION_IS_OTHER_TEMP in this case?
>I noticed that while other parts of tablecmds.c don’t use the macro,
>all other files consistently use RELATION_IS_OTHER_TEMP.
Agreed, RELATION_IS_OTHER_TEMP is better. Changed.
The fix will be in the next patch.
2.
>+/*
>+* We intended to create the partition with the same persistence as the
>+* parent table, but we still need to recheck because that might be
>+* affected by the search_path. If the parent is permanent, so must be
>+* all of its partitions.
>+*/
>I have trouble understanding how this is possible, can you kindly
>give me some guidance on this logic?
Perhaps this is best explained with an example.
(see src/test/regress/sql/partition_merge.sql).
(a) Create permanent table "t":
SET search_path = partitions_merge_schema, pg_temp, public;
CREATE TABLE t (i int) PARTITION BY RANGE (i);
CREATE TABLE tp_0_1 PARTITION OF t FOR VALUES FROM (0) TO (1);
CREATE TABLE tp_1_2 PARTITION OF t FOR VALUES FROM (1) TO (2);
(b) Attempt to merge persistent partitions tp_0_1, tp_1_2 into
temporary partition tp_0_2:
SET search_path = pg_temp, partitions_merge_schema, public;
-- Can't merge persistent partitions into a temporary partition
ALTER TABLE t MERGE PARTITIONS (tp_0_1, tp_1_2) INTO tp_0_2;
(c) "ALTER TABLE ... MERGE PARTITIONS ..." will return an error:
ERROR: cannot create a temporary relation as partition of permanent
relation "t"
--
With best regards,
Dmitry Koval
Postgres Professional: http://postgrespro.com
