On 1/13/21 11:20 AM, Simon Riggs wrote:
On Sun, Jan 10, 2021 at 1:44 AM Tomas Vondra
<tomas.von...@enterprisedb.com> wrote:
5) WHEN AND
I admit the "WHEN AND" conditions sounds a bit cryptic - it took me a
while to realize what this refers to. Is that a term established by SQL
Standard, or something we invented?
As Vik notes, this refers to the WHEN [NOT] MATCHED AND when-and-clause
so in that case I was referring to the "when-and_clause" portion.
Yes, that is part of the standard.
Yes, I know what it was referring to, and I know that the feature is per
SQL standard. My point is that the "WHEN AND" term may be somewhat
unclear, especially when used in a error message (which typically has
very little context). I don't think SQL standard uses "WHEN AND" at all,
it simply talks about <search conditions> and that's it.
6) walsender.c
Huh, why does this patch touch this at all?
Nothing I added, IIRC, nor am I aware of why that would exist.
7) rewriteHandler.c
I see MERGE "doesn't support" rewrite rules in the sense that it simply
ignores them. Shouldn't it error-out instead? Seems like a foot-gun to
me, because people won't realize this limitation and may not notice
their rules don't fire.
Simply ignoring rules is consistent with COPY, that was the only
reason for that choice. It could certainly throw an error instead.
Makes sense.
8) varlena.c
Again, why are these changes to length checks in a MERGE patch?
Nothing I added, IIRC, nor am I aware of why that would exist.
9) parsenodes.h
Should we rename mergeTarget_relation to mergeTargetRelation? The
current name seems like a mix between two naming schemes.
+1
We've had code from 4-5 people in the patch now, so I will re-review
myself to see if I can shed light on anything.
OK, thanks.
regards
--
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
