On Thu, Feb 13, 2020 at 5:39 PM Julien Rouhaud <rjuju123@gmail.com> wrote:
On Tue, Feb 11, 2020 at 10:06:17PM +0530, Ashutosh Bapat wrote: > On Tue, Feb 11, 2020 at 8:27 AM Andy Fan <zhihui.fan1213@gmail.com> wrote: > > > On Tue, Feb 11, 2020 at 12:22 AM Ashutosh Bapat < > > ashutosh.bapat.oss@gmail.com> wrote: > > > >>> > >>> [PATCH] Erase the distinctClause if the result is unique by > >>> definition > >> > >> I forgot to mention this in the last round of comments. Your patch was > >> actually removing distictClause from the Query structure. Please avoid > >> doing that. If you remove it, you are also removing the evidence that this > >> Query had a DISTINCT clause in it. > > > > Yes, I removed it because it is the easiest way to do it. what is the > > purpose of keeping the evidence? > > > > Julien's example provides an explanation for this. The Query structure is > serialised into a view definition. Removing distinctClause from there means > that the view will never try to produce unique results.
And also I think that this approach will have a lot of other unexpected side effects. Isn't changing the Query going to affect pg_stat_statements queryid computing for instance?
Thanks, the 2 factors above are pretty valuable. so erasing the
distinctClause is not reasonable, I will try another way.