Re: [Proposal] Global temporary tables

Hi All,

Please check the below findings on GTT.
*-- Scenario 1:*
Under "information_schema", We are not allowed to create "temporary table",
whereas we can CREATE/DROP "Global Temporary Table", is it expected ?

postgres=# create temporary table information_schema.temp1(c1 int);
ERROR: cannot create temporary relation in non-temporary schema
LINE 1: create temporary table information_schema.temp1(c1 int);
^

postgres=# create global temporary table information_schema.temp1(c1 int);
CREATE TABLE

postgres=# drop table information_schema.temp1 ;
DROP TABLE

*-- Scenario 2:*
Here I am getting the same error message in both the below cases.
We may add a "global" keyword with GTT related error message.

postgres=# create global temporary table gtt1 (c1 int unique);
CREATE TABLE
postgres=# create temporary table tmp1 (c1 int unique);
CREATE TABLE

postgres=# create temporary table tmp2 (c1 int references gtt1(c1) );
ERROR: constraints on temporary tables may reference only temporary tables

postgres=# create global temporary table gtt2 (c1 int references tmp1(c1) );
ERROR: constraints on temporary tables may reference only temporary tables

Thanks,
Prabhat Sahu

On Tue, Feb 25, 2020 at 2:25 PM 曾文旌(义从) <wenjing(dot)zwj(at)alibaba-inc(dot)com> wrote:

>
>
> 2020年2月24日 下午5:44，Prabhat Sahu <prabhat(dot)sahu(at)enterprisedb(dot)com> 写道：
>
> On Fri, Feb 21, 2020 at 9:10 PM 曾文旌(义从) <wenjing(dot)zwj(at)alibaba-inc(dot)com>
> wrote:
>
>> Hi,
>> I have started testing the "Global temporary table" feature,
>> That's great, I see hope.
>> from "gtt_v11-pg13.patch". Below is my findings:
>>
>> -- session 1:
>> postgres=# create global temporary table gtt1(a int);
>> CREATE TABLE
>>
>> -- seeeion 2:
>> postgres=# truncate gtt1 ;
>> ERROR: could not open file "base/13585/t3_16384": No such file or
>> directory
>>
>> is it expected?
>>
>> Oh ,this is a bug, I fixed it.
>>
> Thanks for the patch.
> I have verified the same, Now the issue is resolved with v12 patch.
>
> Kindly confirm the below scenario:
>
> postgres=# create global temporary table gtt1 (c1 int unique);
> CREATE TABLE
>
> postgres=# create global temporary table gtt2 (c1 int references gtt1(c1)
> );
> ERROR: referenced relation "gtt1" is not a global temp table
>
> postgres=# create table tab2 (c1 int references gtt1(c1) );
> ERROR: referenced relation "gtt1" is not a global temp table
>
> Thanks,
> Prabhat Sahu
>
>
> GTT supports foreign key constraints
> in global_temporary_table_v13-pg13.patch
>
>
> Wenjing
>
>
>
>

--

With Regards,
Prabhat Kumar Sahu
EnterpriseDB: http://www.enterprisedb.com