To handle partition drop when Partition table has FK

[AdarshHD]

pg_partman/sql/functions/drop_partition_time.sql

Line 259 in 14114a3

v_sql := 'DROP TABLE %I.%I';

In the above we are trying to drop the partition directly, if there is an foreign key referring partition table which we are trying to drop then we will start seeing failure which throws error saying that the partition is being referred. Why can't we have approach like below

• First detach the partition which is suppose to be dropped.
• Secondly the drop the partition which it is suppose to drop.

This way having foreign key referring the partitioned table doesn't make any issue when running maintenance.

[somnam]

Bumped into the same issue. This seems to block from using pg_partman on partitioned tables with FK references when having retention_keep_table = false set.

Trying to drop a partitioned table with a FK reference fails with following error:

database-1  | 2025-09-01 09:13:58.494 UTC [839] ERROR:  cannot drop table parent_part_p20250501 because other objects depend on it
database-1  |    CONTEXT: SQL statement "DROP TABLE parent_part_p20250501"
database-1  |    PL/pgSQL function drop_partition_time(text,interval,boolean,boolean,text,timestamp with time zone) line 250 at EXECUTE
database-1  |    PL/pgSQL function partman.run_maintenance(text,boolean,boolean) line 336 at assignment
database-1  |    DETAIL: constraint fk_child_part__parent_id__parent_part on table child_part depends on table parent_part_p20250501
database-1  |    HINT: Use DROP ... CASCADE to drop the dependent objects too.
database-1  |    CONTEXT: PL/pgSQL function drop_partition_time(text,interval,boolean,boolean,text,timestamp with time zone) line 307 at RAISE
database-1  |    PL/pgSQL function partman.run_maintenance(text,boolean,boolean) line 336 at assignment
database-1  |    DETAIL:
database-1  |    HINT:
database-1  | 2025-09-01 09:13:58.494 UTC [839] CONTEXT:  PL/pgSQL function partman.run_maintenance(text,boolean,boolean) line 474 at RAISE
database-1  | 2025-09-01 09:13:58.494 UTC [839] STATEMENT:  SELECT partman.run_maintenance(p_parent_table => 'parent_part', p_analyze => true);

The table has:

Referenced by:
    TABLE "child_part" CONSTRAINT "fk_child_part__parent_id__parent_part" FOREIGN KEY (parent_id) REFERENCES parent_part(id)

@keithf4 Would it be possible to look into the proposed solution in PR #768? Running DETACH PARTITION before DROP TABLE seems to resolve this problem.