Re: PATCH: logical_work_mem and logical streaming of large in-progress transactions

On Wed, Jun 10, 2020 at 2:30 PM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
>
>
> Currently, I am done with a working prototype of using the BufFile
> infrastructure for the tempfile. Meanwhile, I want to discuss a few
> interface changes required for the BufFIle infrastructure.
>
> 1. Support read-write mode for "BufFileOpenShared", Basically, in
> workers we will be opening the xid's changes and subxact files per
> stream, so we need an RW mode even in the open. I have passed a flag
> for the same.
>

Generally file open APIs have mode as a parameter to indicate
read_only or read_write. Using flag here seems a bit odd to me.

> 2. Files should not be closed at the end of the transaction:
> Currently, files opened with BufFileCreateShared/BufFileOpenShared are
> registered to be closed on EOXACT. Basically, we need to open the
> changes file on the stream start and keep it open until stream stop,
> so we can not afford to get it closed on the EOXACT. I have added a
> flag for the same.
>

But where do we end the transaction before the stream stop which can
lead to closure of this file?

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