Re: User Interface for WAL usage data

On Fri, Apr 3, 2020 at 11:14 AM Justin Pryzby <pryzby(at)telsasoft(dot)com> wrote:
>
> On Fri, Apr 03, 2020 at 10:52:02AM +0530, Amit Kapila wrote:
> > On Fri, Apr 3, 2020 at 10:41 AM Justin Pryzby <pryzby(at)telsasoft(dot)com> wrote:
> > >
> > > > > > > > > WAL: records=2359 full page records=42 bytes=447788
> > >
> > > 1) records; 2) pages ("full page images"); 3) bytes
> > >
> > > That is exactly like sort (method/type/size) and hash (buckets/batches/size),
> > > and *not* like buffers, which shows various values all in units of "pages".
> > >
> >
> > The way you have written (2) appears to bit awkward. I would prefer
> > "full page writes" or "full page images".
>
> I didn't mean it to be the description used in the patch or anywhere else, just
> the list of units.
>
> I wonder if it should use colons instead of equals ? As in:
> | WAL: Records: 2359 Full Page Images: 42 Size: 437kB
>
> Note, that has: 1) two spaces; 2) capitalized "fields"; 3) size rather than
> "bytes". That's similar to Buckets:
> | Buckets: 1024 Batches: 1 Memory Usage: 44kB
>
> I'm not sure if it should say "WAL: " or "WAL ", or perhaps "WAL: " If
> there's no colon, then it looks like the first field is "WAL Records", but then
> "size" isn't as tightly associated with WAL. It could say:
> | WAL Records: n Full Page Images: n WAL Size: nkB
>
> For comparison, buffers uses "equals" for the case showing multiple "fields",
> which are all in units of pages:
> | Buffers: shared hit=15 read=2006
>

I think this is more close to the case of Buffers where all fields are
directly related to buffers/blocks. Here all the fields we want to
display are related to WAL, so we should try to make it display
similar to Buffers.

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