Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints

On Thu, Dec 9, 2021 at 11:12 AM Ashutosh Sharma <ashu.coek88@gmail.com> wrote:

Hi,

The issue here is that we are trying to create a table that exists inside a non-default tablespace when doing ALTER DATABASE. I think this should be skipped otherwise we will come across the error like shown below:

ashu@postgres=# alter database test set tablespace pg_default;
ERROR:  58P02: could not create file "pg_tblspc/16385/PG_15_202111301/16386/16390": File exists

 

Thanks Ashutosh for the patch, the mentioned issue has been resolved with the patch.

But I am still able to reproduce the crash consistently on top of this patch + v7 patches,just the test case has been modified.

create tablespace tab1 location '<dir_path>/test1';

create tablespace tab location '<dir_path>/test';

create database test tablespace tab;

\c test

create table t( a int PRIMARY KEY,b text);

CREATE OR REPLACE FUNCTION large_val() RETURNS TEXT LANGUAGE SQL AS 'select array_agg(md5(g::text))::text from generate_series(1, 256) g';

insert into t values (generate_series(1,100000), large_val());

alter table t set tablespace tab1 ;

\c postgres

create database test1 template test;

\c test1

alter table t set tablespace tab;

\c postgres

alter database test1 set tablespace tab1;

--Cancel the below command after few seconds

alter database test1 set tablespace pg_default;

\c test1
alter table t set tablespace tab1;

Logfile Snippet:

2021-12-09 17:49:18.110 +04 [18151] PANIC:  could not fsync file "base/116398/116400": No such file or directory
2021-12-09 17:49:19.105 +04 [18150] LOG:  checkpointer process (PID 18151) was terminated by signal 6: Aborted
2021-12-09 17:49:19.105 +04 [18150] LOG:  terminating any other active server processes