| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | Amit Khandekar <amitdkhan(dot)pg(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: pgsql: Avoid coercing a whole-row variable that is already coerced |
| Date: | 2017-10-13 16:56:31 |
| Message-ID: | 29947.1507913791@sss.pgh.pa.us |
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| Lists: | pgsql-hackers |
Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Fri, Oct 13, 2017 at 5:57 AM, Amit Khandekar <amitdkhan(dot)pg(at)gmail(dot)com> wrote:
>> One thing we can do is : instead of calling
>> map_variable_attnos_mutator(), convert the var inside the if block for
>> "if (IsA(node, ConvertRowtypeExpr))". Please check the attached patch.
>> There, I have avoided coerced_var context variable.
> Tom, is this more like what you have in mind?
It's better ... but after reading the patched code, a lot of my remaining
beef is with the lack of clarity of the comments. You need ESP to
understand what the function is trying to accomplish and what the
constraints are. I'll take a whack at improving that and push.
regards, tom lane
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