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

On Thu, Dec 9, 2021 at 6:57 AM Neha Sharma <neha(dot)sharma(at)enterprisedb(dot)com> wrote:
>
> While testing the v7 patches, I am observing a crash with the below test case.
>
> Test case:
> create tablespace tab location '<dir_path>/test_dir';
> create tablespace tab1 location '<dir_path>/test_dir1';
> 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(1,2000000), large_val());
> alter table t set tablespace tab1 ;
> \c postgres
> create database test1 template test;
> alter database test set tablespace pg_default;
> alter database test set tablespace tab;
> \c test1
> alter table t set tablespace tab;
>
> Logfile says:
> 2021-12-08 23:31:58.855 +04 [134252] PANIC: could not fsync file "base/16386/4152": No such file or directory
> 2021-12-08 23:31:59.398 +04 [134251] LOG: checkpointer process (PID 134252) was terminated by signal 6: Aborted
>

I tried to reproduce the issue using your test scenario, but I needed
to reduce the amount of inserted data (so reduced 2000000 to 20000)
due to disk space.
I then consistently get an error like the following:

postgres=# alter database test set tablespace pg_default;
ERROR: could not create file
"pg_tblspc/16385/PG_15_202111301/16386/36395": File exists

(this only happens when the patch is used)

Regards,
Greg Nancarrow
Fujitsu Australia