Re: [Proposal] Global temporary tables

Thanks for review.


> 2020年2月25日 下午9:56，tushar <tushar.ahuja@enterprisedb.com> 写道：
> 
> Hi ,
> 
> pg_upgrade  scenario is failing if database is containing  global temporary table 
> 
> =============================
> centos@tushar-ldap-docker bin]$ ./psql postgres
> psql (13devel)
> Type "help" for help.
> 
> postgres=# create global temporary table  t(n int);
> CREATE TABLE
> postgres=# \q
> ===============================
> 
> run pg_upgrade -
> 
> [centos@tushar-ldap-docker bin]$ ./pg_upgrade -d /tmp/t1/ -D /tmp/t2 -b . -B . 
> Performing Consistency Checks
> -----------------------------
> Checking cluster versions                                             ok
> Checking database user is the install user                   ok
> Checking database connection settings                       ok
> Checking for prepared transactions                             ok
> Checking for reg* data types in user tables                 ok
> --
> --
> If pg_upgrade fails after this point, you must re-initdb the
> new cluster before continuing.
> 
> Performing Upgrade
> ------------------
> Analyzing all rows in the new cluster                        ok
> Freezing all rows in the new cluster                          ok
> Deleting files from new pg_xact                                ok
> --
> --
> Restoring database schemas in the new cluster
>                                                                                   ok
> Copying user relation files
>   /tmp/t1/base/13585/16384                                  
> error while copying relation "public.t": could not open file "/tmp/t1/base/13585/16384": No such file or directory
> Failure, exiting
This is a bug.
I fixed in global_temporary_table_v14-pg13.patch


Wenjing




> 
> regards,
> 
> On 2/25/20 7:06 PM, Prabhat Sahu wrote:
>> 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.zwj@alibaba-inc.com <mailto:wenjing.zwj@alibaba-inc.com>> wrote:
>> 
>> 
>>> 2020年2月24日 下午5:44，Prabhat Sahu <prabhat.sahu@enterprisedb.com <mailto:prabhat.sahu@enterprisedb.com>> 写道：
>>> 
>>> On Fri, Feb 21, 2020 at 9:10 PM 曾文旌(义从) <wenjing.zwj@alibaba-inc.com <mailto:wenjing.zwj@alibaba-inc.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 <http://www.enterprisedb.com/>
> 
> -- 
> regards,tushar
> EnterpriseDB  https://www.enterprisedb.com/ <https://www.enterprisedb.com/>
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