pg_temp schema created while using DB Link

Started by Jill Jadealmost 6 years ago5 messagesgeneral
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#1Jill Jade
jill779ks@gmail.com

Hello Everyone,

We have an issue with DB_Link from Oracle to PostgreSQL. When we try to
access tables from Oracle database via DB_link, temp
schemas(pg_temp,pg_toast) are automatically created in the database while
using the query below.

*create table as select * from table@oralink *

[image: image.png]

Even if we reload the database, the temp schemas are still there.

Do you know the reason why the temp schemas are being created
with DB_link?Does anyone has a solution for this problem?

Thank you

Regards,
Jill

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#2Laurenz Albe
laurenz.albe@cybertec.at
In reply to: Jill Jade (#1)
Re: pg_temp schema created while using DB Link

On Fri, 2020-05-08 at 10:11 +0400, Jill Jade wrote:

We have an issue with DB_Link from Oracle to PostgreSQL. When we try to access tables from
Oracle database via DB_link, temp schemas(pg_temp,pg_toast) are automatically created
in the database while using the query below.

create table as select * from table@oralink

Even if we reload the database, the temp schemas are still there.

Do you know the reason why the temp schemas are being created with DB_link?
Does anyone has a solution for this problem?

These schemas contain temporary tables and are not connected to your connection
from Oracle (unless you create temporary tables via that connection).

They are an implementation detail and should not bother you.

What is your problem with these schemmas?

Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com

#3Jill Jade
jill779ks@gmail.com
In reply to: Laurenz Albe (#2)
Re: pg_temp schema created while using DB Link

Hello

We do not have any temporary tables in the Oracle database. The temporary
schema is created only while using the db_link. These temp schemas
(pg_temp, pg_toast) are not disappearing even after restarting the database.

These are empty schemas that do not contain anything (tables, views etc).
And these schemas keep on increasing each time the query using the db_link
is run.

Why the db_link is causing these schemas? Is there any issue with db_link?

Thanks

Regards,
Jill

On Fri, 8 May 2020 at 10:36, Laurenz Albe <laurenz.albe@cybertec.at> wrote:

Show quoted text

On Fri, 2020-05-08 at 10:11 +0400, Jill Jade wrote:

We have an issue with DB_Link from Oracle to PostgreSQL. When we try to

access tables from

Oracle database via DB_link, temp schemas(pg_temp,pg_toast) are

automatically created

in the database while using the query below.

create table as select * from table@oralink

Even if we reload the database, the temp schemas are still there.

Do you know the reason why the temp schemas are being created with

DB_link?

Does anyone has a solution for this problem?

These schemas contain temporary tables and are not connected to your
connection
from Oracle (unless you create temporary tables via that connection).

They are an implementation detail and should not bother you.

What is your problem with these schemmas?

Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com

#4Thomas Kellerer
shammat@gmx.net
In reply to: Jill Jade (#3)
Re: pg_temp schema created while using DB Link

Jill Jade schrieb am 08.05.2020 um 09:32:

We do not have any temporary tables in the Oracle database. The
temporary schema is created only while using the db_link. These temp
schemas (pg_temp, pg_toast) are not disappearing even after
restarting the database.

The temp tables would be created in Postgres, not in Oracle.

Why the db_link is causing these schemas? Is there any issue with db_link?

Which DB_Link are you referring to exactly?

Postgres' "dblink" module can only connect to another Postgres server.
So it must be something on the Oracle side.

#5Adrian Klaver
adrian.klaver@aklaver.com
In reply to: Jill Jade (#3)
Re: pg_temp schema created while using DB Link

On 5/8/20 12:32 AM, Jill Jade wrote:

Hello

We do not have any temporary tables in the Oracle database. The
temporary schema is created only while using the db_link. These temp
schemas (pg_temp, pg_toast) are not disappearing even after restarting
the database.

These are empty schemas that do not contain anything (tables, views
etc). And these schemas keep on increasing each time the query using the
db_link is run.

Postgres will keep empty pg_temp schemas around rather then having to
recreate them the next time they are needed. Not sure where the cutoff
is for number?

Why the db_link is causing these schemas? Is there any issue with db_link?

Thanks

Regards,
Jill

On Fri, 8 May 2020 at 10:36, Laurenz Albe <laurenz.albe@cybertec.at
<mailto:laurenz.albe@cybertec.at>> wrote:

On Fri, 2020-05-08 at 10:11 +0400, Jill Jade wrote:

We have an issue with DB_Link from Oracle to PostgreSQL. When we

try to access tables from

Oracle database via DB_link, temp schemas(pg_temp,pg_toast) are

automatically created

in the database while using the query below.

create table as select * from table@oralink

Even if we reload the database, the temp schemas are still there.

Do you know the reason why the temp schemas are being created

with DB_link?

Does anyone has a solution for this problem?

These schemas contain temporary tables and are not connected to your
connection
from Oracle (unless you create temporary tables via that connection).

They are an implementation detail and should not bother you.

What is your problem with these schemmas?

Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com

--
Adrian Klaver
adrian.klaver@aklaver.com