Обсуждение: pg_restore failed on foreign key constraint

On Thu, 2026-02-12 at 16:35 -0500, Ron Johnson wrote:
> When running pg_restore 17.7 against a PG 14.20 database directory dump, I got this in the log:
>
> pg_restore: while PROCESSING TOC:
> pg_restore: from TOC entry 171927; 2606 3149123877 FK CONSTRAINT rel_user_email fk_rel_user_email_2 TAP
> pg_restore: error: could not execute query: ERROR:  insert or update on table "rel_user_email" violates foreign key
constraint"fk_rel_user_email_2" 
> DETAIL:  Key (access_email_id)=(2073) is not present in table "access_email".
> Command was: ALTER TABLE ONLY public.rel_user_email
>     ADD CONSTRAINT fk_rel_user_email_2 FOREIGN KEY (access_email_id) REFERENCES public.access_email(access_email_id);
>
> So, I went to the source database:
>
> TAPd=# \d rel_user_email
>                          Table "public.rel_user_email"
>      Column      |            Type             | Collation | Nullable | Default
> -----------------+-----------------------------+-----------+----------+---------
>  user_id         | integer                     |           | not null |
>  access_email_id | integer                     |           | not null |
>  modified_by     | integer                     |           |          |
>  modified_on     | timestamp without time zone |           | not null |
> Indexes:
>     "idx_rel_user_email" UNIQUE, btree (user_id, access_email_id)
> Foreign-key constraints:
>     "fk_rel_user_email_1" FOREIGN KEY (user_id) REFERENCES access_user(user_id)
>     "fk_rel_user_email_2" FOREIGN KEY (access_email_id) REFERENCES access_email(access_email_id)
>
> TAPd=# select * from rel_user_email where access_email_id=2073;
>  user_id | access_email_id | modified_by |       modified_on      
> ---------+-----------------+-------------+-------------------------
>     2452 |            2073 |          41 | 2013-03-11 10:52:20.331
> (1 row)
>
> TAPd=# \d access_email
>                                                  Table "public.access_email"
>      Column      |            Type             | Collation | Nullable |                        Default              
         
>
-----------------+-----------------------------+-----------+----------+-------------------------------------------------------
>  access_email_id | integer                     |           | not null |
nextval('access_email_access_email_id_seq'::regclass)
>  type            | numeric(10,0)               |           |          |
>  email_address   | character varying(255)      |           |          |
>  created_on      | timestamp without time zone |           | not null |
>  modified_on     | timestamp without time zone |           |          |
>  created_by      | integer                     |           |          |
>  modified_by     | integer                     |           |          |
> Indexes:
>     "pk_access_email" PRIMARY KEY, btree (access_email_id)
> Referenced by:
>     TABLE "rel_user_email" CONSTRAINT "fk_rel_user_email_2" FOREIGN KEY (access_email_id) REFERENCES
access_email(access_email_id)
>
> TAPd=# select * from access_email where access_email_id=2073;
>  access_email_id | type | email_address | created_on | modified_on | created_by | modified_by
> -----------------+------+---------------+------------+-------------+------------+-------------
> (0 rows)
>
> Looks like index corruption.  
>
> $ pg_amcheck -t public.rel_user_email -t public.access_email TAPd
> $ echo $?
> 0
> $ pg_amcheck -i idx_rel_user_email -i pk_access_email --parent-check --heapallindexed TAPd
> $ echo $?
> 0
>
> But amcheck shows no problems.
>
> Before I get worried that there' s corrupt data: am I missing something obvious?

Try

  SET enable_indexscan = off;

  SELECT * FROM access_email WHERE access_email_id = 2073;

Only if that returns a row, I would assume index corruption, and that one should have been
caught with "heapallindexed".

It is the foreign key that is violated.  The normal ways to end up with broken foreign
keys are

  SET session_replication_role = replica;

and

  ALTER TABLE rel_user_email DISABLE TRIGGER ALL;

both of which require superuser privileges.

Yours,
Laurenz Albe

On 2/13/26 06:18, Ron Johnson wrote:
> On Fri, Feb 13, 2026 at 1:43 AM Laurenz Albe <laurenz.albe@cybertec.at 
> <mailto:laurenz.albe@cybertec.at>> wrote:

> Turns out that there's a nightly cron job that dumps this (and other) 
> tables with the "--data-only --disable-triggers" options and then does 
> "psql -Xaf mumble.sql" to load them into this database.
> 
> But access_email_id=2073 is in the source access_email, so I've got to 
> figure out why it's not being loaded into the target.

Is it in the dump file from the source?

> 
> -- 
> Death to <Redacted>, and butter sauce.
> Don't boil me, I'm still alive.
> <Redacted> lobster!


-- 
Adrian Klaver
adrian.klaver@aklaver.com

On 2/13/26 08:05, Ron Johnson wrote:
> On Fri, Feb 13, 2026 at 10:55 AM Adrian Klaver 
> <adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>> wrote:
> 
>     On 2/13/26 06:18, Ron Johnson wrote:
>      > On Fri, Feb 13, 2026 at 1:43 AM Laurenz Albe
>     <laurenz.albe@cybertec.at <mailto:laurenz.albe@cybertec.at>
>      > <mailto:laurenz.albe@cybertec.at
>     <mailto:laurenz.albe@cybertec.at>>> wrote:
> 
>      > Turns out that there's a nightly cron job that dumps this (and
>     other)
>      > tables with the "--data-only --disable-triggers" options and then
>     does
>      > "psql -Xaf mumble.sql" to load them into this database.
>      >
>      > But access_email_id=2073 is in the source access_email, so I've
>     got to
>      > figure out why it's not being loaded into the target.
> 
>     Is it in the dump file from the source?
> 
> 
> Some tables aren't being dumped at the source;  Thus, the missing records.

Un-confuse me, how do the below relate?:

"Turns out that there's a nightly cron job that dumps this (and other) 
tables with the "--data-only --disable-triggers" options and then does 
"psql -Xaf mumble.sql" to load them into this database.

But access_email_id=2073 is in the source access_email, so I've got to 
figure out why it's not being loaded into the target."

and

"Some tables aren't being dumped at the source"

> 
> -- 
> Death to <Redacted>, and butter sauce.
> Don't boil me, I'm still alive.
> <Redacted> lobster!


-- 
Adrian Klaver
adrian.klaver@aklaver.com

On 2/13/26 8:40 AM, Ron Johnson wrote:
> On Fri, Feb 13, 2026 at 11:14 AM Adrian Klaver 

> 
>     Un-confuse me, how do the below relate?:
> 
>     "Turns out that there's a nightly cron job that dumps this (and other)
>     tables with the "--data-only --disable-triggers" options and then does
>     "psql -Xaf mumble.sql" to load them into this database.
> 
>     But access_email_id=2073 is in the source access_email, so I've got to
>     figure out why it's not being loaded into the target."
> 
>     and
> 
>     "Some tables aren't being dumped at the source"
> 
> 
> Table name            Source Dumped   Target Loaded
> public.access_email   No              No
> public.rel_user_email Yes             Yes
> 
> Thus, while new and modified records are being added 
> to public.access_email at the source, they are not making it to the 
> Target database.  That plus "--disable-triggers" lets 
> the public.rel_user_email loads succeed on the target even though it 
> breaks RI.

This means you know what the issue is now?

> 
> -- 
> Death to <Redacted>, and butter sauce.
> Don't boil me, I'm still alive.
> <Redacted> lobster!