[ovirt-devel] Important changes in the Search Engine code

[Moti Asayag]

----- Original Message -----
> From: "Eli Mesika" <emesika at redhat.com>
> To: "engine-devel at ovirt.org" <devel at ovirt.org>
> Sent: Wednesday, March 11, 2015 10:48:44 AM
> Subject: [ovirt-devel] Important changes in the Search Engine code
> 
> Hi All
> 
> We had in the past many cases in which the search engine returned duplicate
> records.
> Most of those cases are not simple to resolve in the DB layer by changing the
> query due to schema limitations.
> We had decided to handle that by adding DISTINCT to the queries that the
> search engine generates  [1]

Wouldn't that cause some penalty for each query ? Each navigation between tabs in
the UI will become slower now that the returned values need to be sorted, even when
not required ?

> However, we might have cases in which both DISTINCT and ORDER BY f({args})
> (where f is a function call) is used
> In that case, we will get SQL exception since the ORDER BY is applied on the
> DISTINCT result that does not include f as a field.
> I had prevented using DISTINCT in such cases [2]
> That means that you still may got duplicates in such cases and then you
> should handle it in the same method as in [3]
> (basically returning the function result in the select as a computed field)
> 
> 
> [1] https://gerrit.ovirt.org/#/c/31896
> [2] https://gerrit.ovirt.org/#/c/38459
> [3] https://gerrit.ovirt.org/#/c/36946
> 
> 
> Thanks
> Eli Mesika
> 
> _______________________________________________
> Devel mailing list
> Devel at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/devel
>