Isolation of table creation

Started by Alexander Korotkovover 10 years ago2 messageshackers
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#1Alexander Korotkov
aekorotkov@gmail.com

Hackers,

I discovered interesting issue with PostgreSQL transaction isolation.
When transaction is in repeatable read isolation level, I can't see table
which was created after transaction obtained snapshot. But I can run DML
statements with this table. See example below.

Session 1
# begin transaction isolation level repeatable read;
BEGIN
# \dt
No relations found.
Session 2
# create table tmp (i int not null);
CREATE TABLE
# insert into tmp values (1);
INSERT 0 1
# \dt
No relations found.
# select * from tmp;
i
---
(0 rows)

# insert into tmp values (2);
INSERT 0 1
# select * from tmp;
i
---
2
(1 row)
# commit;
COMMIT

Is it a bug?

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company

#2Andres Freund
andres@anarazel.de
In reply to: Alexander Korotkov (#1)
Re: Isolation of table creation

On 2015-12-11 11:46:11 +0300, Alexander Korotkov wrote:

I discovered interesting issue with PostgreSQL transaction isolation.
When transaction is in repeatable read isolation level, I can't see table
which was created after transaction obtained snapshot. But I can run DML
statements with this table. See example below.

Is it a bug?

No, that's pretty much expected. Parse analysis, planning use fresh
catalog snapshot, whereas psql's schema queries use the transaction
snapshot.

Andres

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