Re: [HACKERS] Block level parallel vacuum

On Tue, Dec 3, 2019 at 12:55 PM tushar <tushar(dot)ahuja(at)enterprisedb(dot)com>
wrote:

> On 11/27/19 11:13 PM, Masahiko Sawada wrote:
> > Thank you for reviewing this patch. All changes you made looks good to
> me.
> >
> > I thought I already have posted all v34 patches but didn't, sorry. So
> > I've attached v35 patch set that incorporated your changes and it
> > includes Dilip's patch for gist index (0001). These patches can be
> > applied on top of the current HEAD and make check should pass.
> > Regards,
> While doing testing of this feature against v35- patches ( minus 004) on
> Master ,
>

Thanks for doing the testing of these patches.

> getting crash when user connect to server using single mode and try to
> perform vacuum (parallel 1 ) o/p
>
> tushar(at)localhost bin]$ ./postgres --single -D data/ postgres
> 2019-12-03 12:49:26.967 +0530 [70300] LOG: database system was
> interrupted; last known up at 2019-12-03 12:48:51 +0530
> 2019-12-03 12:49:26.987 +0530 [70300] LOG: database system was not
> properly shut down; automatic recovery in progress
> 2019-12-03 12:49:26.990 +0530 [70300] LOG: invalid record length at
> 0/29F1638: wanted 24, got 0
> 2019-12-03 12:49:26.990 +0530 [70300] LOG: redo is not required
>
> PostgreSQL stand-alone backend 13devel
> backend>
> backend> vacuum full;
> backend> vacuum (parallel 1);
>

The parallel vacuum shouldn't be allowed via standalone backends as we
can't create DSM segments in that mode and similar is true for the parallel
query. It should internally proceed with a serial vacuum. I'll fix it in
the next version I am planning to post. BTW, it seems that the same
problem will be there for parallel create index.

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com