[Engine-devel] [Devel] vds_dynamic refactor

[Itamar Heim]

On 04/04/2014 04:30 AM, Liran Zelkha wrote:
>
>
>
> On Thu, Apr 3, 2014 at 8:40 PM, Gilad Chaplik <gchaplik at redhat.com
> <mailto:gchaplik at redhat.com>> wrote:
>
>     ----- Original Message -----
>      > From: "Liran Zelkha" <liran.zelkha at gmail.com
>     <mailto:liran.zelkha at gmail.com>>
>      > To: "Gilad Chaplik" <gchaplik at redhat.com
>     <mailto:gchaplik at redhat.com>>
>      > Cc: "Omer Frenkel" <ofrenkel at redhat.com
>     <mailto:ofrenkel at redhat.com>>, "Eli Mesika" <emesika at redhat.com
>     <mailto:emesika at redhat.com>>, "engine-devel" <engine-devel at ovirt.org
>     <mailto:engine-devel at ovirt.org>>,
>      > devel at linode01.ovirt.org <mailto:devel at linode01.ovirt.org>
>      > Sent: Thursday, April 3, 2014 7:51:39 PM
>      > Subject: Re: [Engine-devel] vds_dynamic refactor
>      >
>      > On Thu, Apr 3, 2014 at 5:33 PM, Gilad Chaplik
>     <gchaplik at redhat.com <mailto:gchaplik at redhat.com>> wrote:
>      >
>      > > *From: *"Liran Zelkha" <liran.zelkha at gmail.com
>     <mailto:liran.zelkha at gmail.com>>
>      > > *To: *"Gilad Chaplik" <gchaplik at redhat.com
>     <mailto:gchaplik at redhat.com>>
>      > > *Cc: *"Omer Frenkel" <ofrenkel at redhat.com
>     <mailto:ofrenkel at redhat.com>>, "Eli Mesika" <
>      > > emesika at redhat.com <mailto:emesika at redhat.com>>, "engine-devel"
>     <engine-devel at ovirt.org <mailto:engine-devel at ovirt.org>>
>      > > *Sent: *Thursday, April 3, 2014 5:27:56 PM
>      > > *Subject: *Re: [Engine-devel] vds_dynamic refactor
>      > >
>      > > True but that's no reason to have a bad schema
>      > >
>      > > I'm open to new ideas and truly want to understand what is bad?
>      > >
>      > The problem is with both updates and selects.
>      > For selects - to get all the information for the VDS we have multiple
>      > joins. Adding another one will hurt performance even more.
>
>     What about creating the VDS list in the db. i.e. your patch [1]
>     about constructing VDS objects in the engine, should occur in the db
>     within a SP, and should be transparent to the server. that will
>     solve the multiple table join.
>
>
> The joins are happening on the server. We have a VDS view that brings in
> information from many tables and we retrieve rows from it all the time.
> Just run an explain on a select * from vds and see for yourself.

thought the distinction was vds_static is updated by user 
(configuration), where as vds_dyanmic/statistics is reported from vdsm 
(slow/fast updates).

please remember joining them to one table, also means DWH will ETA all 
of data each time. today it will only copy statistics if dynamic did not 
change.