| From: | David Rowley <dgrowleyml(at)gmail(dot)com> |
|---|---|
| To: | Peter Eisentraut <peter(at)eisentraut(dot)org> |
| Cc: | pgsql-committers(at)lists(dot)postgresql(dot)org |
| Subject: | Re: pgsql: Add DISTINCT to information schema usage views |
| Date: | 2021-04-21 13:43:43 |
| Message-ID: | CAApHDvoT1fXHAanzJSWLmLsu8KJ3EUATtVE1nuwHsgse66EOgw@mail.gmail.com |
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| Lists: | pgsql-committers |
On Wed, 21 Apr 2021 at 22:32, Peter Eisentraut <peter(at)eisentraut(dot)org> wrote:
> Add DISTINCT to information schema usage views
What do you think of the idea of just getting rid of all these
DISTINCTs and instead do a semi-join so that we don't get duplicate
rows?
For me, I don't really like the DISTINCTs as the behaviour is prone to
change as the target list changes in the view. Maybe these views are
standard enough that that's not going to happen very often, but it
could.
The 2nd reason I'm not a fan of using DISTINCT is that it's really
chopping the problem off at the tail instead of the head.
I've attached a patch that gets rid of all the DISTINCTs.
David
| Attachment | Content-Type | Size |
|---|---|---|
| use_exists_instead_of_distinct_in_information_schema_views.patch | application/octet-stream | 17.5 KB |
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