Re: Dropping a database that does not exist

Hi,

I've been getting duplicate databases within my server. Dropping one of
them works, but when I try to drop the other, psql will say that the
database does not exist.

For example:

db1
db1
db2
db3
db4
db4
db5

Running DROP DATABASE db1 for the first time works and I'm left with:

db1
db2
db3
db4
db4
db5

Attempting to run DROP DATABASE db1 again will just give me "FATAL:
database "db1" does not exist"

Same scenario for db4.

I could ignore the error, but because of the duplicate database, I
cannot make a dump of the server.

Any one has any ideas why this is happening and how I can solve it? A
similar thing happened previously, but it was with tables within a
database. The only way we solved that was by dropping the database and
recreating the structure, which wasn't the ideal way I wanted to use.
I've got PostgreSQL 8.0.4 running on SuSE 9.3.

Regards,
Shiming

Tham Shiming <shiming(at)misatravel(dot)com> writes:
> I've been getting duplicate databases within my server.

What exactly makes you think you have that?

regards, tom lane

I don't think you have duplicate databases - that would be the first time I
heard that postgreSQL supports that.
Are you sure you didn't create the database with a name that just doesn't
print?
I.e. a simple

createdb test

works.
do another

createdb "test "

(note the space)
works too, but when you list the db's you'll see test twice, although the one
of them is created with a space at the end, so you can't connect to it or
drop it unless you use quotes. Did you use some kind of tool that may have a
done this? Most tools use quotes when creating sql statements, so if you
accidentially added a space in the dialog you end up with a scenario like you
describe.

On Friday 10 February 2006 01:42, Tham Shiming wrote:
> Hi,
>
> I've been getting duplicate databases within my server. Dropping one of
> them works, but when I try to drop the other, psql will say that the
> database does not exist.
>
> For example:
>
> db1
> db1
> db2
> db3
> db4
> db4
> db5
>
> Running DROP DATABASE db1 for the first time works and I'm left with:
>
> db1
> db2
> db3
> db4
> db4
> db5
>
> Attempting to run DROP DATABASE db1 again will just give me "FATAL:
> database "db1" does not exist"
>
> Same scenario for db4.
>
> I could ignore the error, but because of the duplicate database, I
> cannot make a dump of the server.
>
> Any one has any ideas why this is happening and how I can solve it? A
> similar thing happened previously, but it was with tables within a
> database. The only way we solved that was by dropping the database and
> recreating the structure, which wasn't the ideal way I wanted to use.
> I've got PostgreSQL 8.0.4 running on SuSE 9.3.
>
> Regards,
> Shiming
>
>
>
>
> ---------------------------(end of broadcast)---------------------------
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>
> http://www.postgresql.org/docs/faq

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"Uwe C. Schroeder" <uwe(at)oss4u(dot)com> writes:
> I don't think you have duplicate databases - that would be the first time I
> heard that postgreSQL supports that.
> Are you sure you didn't create the database with a name that just doesn't
> print?

That's one possibility that I was wondering about; another was there
somehow being two entries in pg_shadow for the same usesysid, which'd
result in apparent "duplicate" output from queries that involve joining
pg_database and pg_shadow. That's why I wanted to know exactly what
was leading to the conclusion that there were duplicate databases.

regards, tom lane

Well, not exactly support. We didn't create the duplicate databases, it
just appear suddenly out of nowhere, which was also odd.

OK, checking pg_shadow, the usesysid for each entry is unique.
pg_database, however, showed the duplicate databases. A short sample
output from pgAdmin.

datname datdba
db1 101
db1 101
db2 102
db3 103
db3 103

Whether there is a significance, I am not really sure. Hopefully, one of
you can help us.

None of our code will create a database, and we will not manually create
one unless requirements forces us to do it.

Regards,
Shiming

Tom Lane wrote:
> "Uwe C. Schroeder" <uwe(at)oss4u(dot)com> writes:
>
>> I don't think you have duplicate databases - that would be the first time I
>> heard that postgreSQL supports that.
>> Are you sure you didn't create the database with a name that just doesn't
>> print?
>>
>
> That's one possibility that I was wondering about; another was there
> somehow being two entries in pg_shadow for the same usesysid, which'd
> result in apparent "duplicate" output from queries that involve joining
> pg_database and pg_shadow. That's why I wanted to know exactly what
> was leading to the conclusion that there were duplicate databases.
>
> regards, tom lane
>
>
>

Tham Shiming <shiming(at)misatravel(dot)com> writes:
> OK, checking pg_shadow, the usesysid for each entry is unique.
> pg_database, however, showed the duplicate databases. A short sample
> output from pgAdmin.

> datname datdba
> db1 101
> db1 101
> db2 102
> db3 103
> db3 103

Does anyone know what the underlying query is that pgadmin uses for
this display?

regards, tom lane