| From: | Andres Freund <andres(at)anarazel(dot)de> |
|---|---|
| To: | Jeff Davis <pgsql(at)j-davis(dot)com> |
| Cc: | Bharath Rupireddy <bharath(dot)rupireddyforpostgres(at)gmail(dot)com>, Dilip Kumar <dilipbalaut(at)gmail(dot)com>, Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com>, pgsql-hackers(at)lists(dot)postgresql(dot)org |
| Subject: | Re: Improve WALRead() to suck data directly from WAL buffers when possible |
| Date: | 2023-01-14 20:34:03 |
| Message-ID: | 20230114203403.4zpg72fw2qb34awf@awork3.anarazel.de |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Hi,
On 2023-01-14 00:48:52 -0800, Jeff Davis wrote:
> On Mon, 2022-12-26 at 14:20 +0530, Bharath Rupireddy wrote:
> > Please review the attached v2 patch further.
>
> I'm still unclear on the performance goals of this patch. I see that it
> will reduce syscalls, which sounds good, but to what end?
>
> Does it allow a greater number of walsenders? Lower replication
> latency? Less IO bandwidth? All of the above?
One benefit would be that it'd make it more realistic to use direct IO for WAL
- for which I have seen significant performance benefits. But when we
afterwards have to re-read it from disk to replicate, it's less clearly a win.
Greetings,
Andres Freund
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Justin Pryzby | 2023-01-14 20:57:07 | Re: Support for dumping extended statistics |
| Previous Message | Tom Lane | 2023-01-14 20:06:06 | Re: Extracting cross-version-upgrade knowledge from buildfarm client |