When an index and a constraint have the same name...

jason@buberel.org writes:

Seems as though I've gotten myself into something of a pickle:
I wound up with a fkey constraint and an index on the same table having the
same name ('rs_fkey').

That shouldn't be a problem particularly.

The result is an error message when I try to drop the table (cascade) or
even drop the constraint:
# alter table report_specification drop constraint rs_pkey;
NOTICE: constraint pr_rs on table purchase_record depends on index rs_pkey
ERROR: "rs_pkey" is an index

That seems odd. What PG version is this exactly ("8.1" is not good
enough)? What does psql show for "\d report_specification" and
"\d purchase_record"?

regards, tom lane

Thanks for taking a look Tom:

I am running postgres 8.1.4 on RedHet (CentOS) v4.0. Here is the
description of the purchase_record table (somewhat abbreviated with
uninvolved columns omitted):

# \d purchase_record
Table "public.purchase_record"
Column | Type | Modifiers
----------------------------+---------+----------------------------------------------------
purchase_record_id | bigint | not null default 0
report_specification_id | bigint |
Indexes:
"pr_pkey" PRIMARY KEY, btree (purchase_record_id)
"fki_pr_rs" btree (report_specification_id)
Foreign-key constraints:
"pr_rs" FOREIGN KEY (report_specification_id) REFERENCES
report_specification(report_specification_id) ON UPDATE RESTRICT ON
DELETE CASCADE

# \d report_specification
Table "public.report_specification"
Column | Type | Modifiers
-------------------------+-----------------------+---------------------------------------
report_specification_id | bigint | not null
report_template_id | bigint |
Indexes:
"rs_pkey" PRIMARY KEY, btree (report_specification_id)
"fki_rs_rt_fkey" btree (report_template_id)

Regards,
Jason

Tom Lane wrote:

"Jason L. Buberel" <jason@buberel.org> writes:

Thanks for taking a look Tom:
I am running postgres 8.1.4 on RedHet (CentOS) v4.0. Here is the
description of the purchase_record table (somewhat abbreviated with
uninvolved columns omitted):

Well, I was hoping I could duplicate the problem, but I can't; which
means either that it's been fixed since 8.1.4 (but I don't see anything
very relevant-looking in the CVS logs) or that there's some critical
factor we haven't identified about your table definitions.

Could you send me the full "pg_dump -s" output for the two tables?
And/or a stack trace from the point of the errfinish() call? (Note
there will be two errfinish calls, one to print the NOTICE and one
to print the ERROR --- we want to know where the second one comes from.)

regards, tom lane