Re: [GENERAL] Using Variables in Queries

"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Thu, Oct 19, 2017 at 12:14 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> FROM  products,
>> (values ('red widget'::text)) consts(target)
>> WHERE similarity(target, item_name) > 0.25
>> ORDER BY target <<-> item_name
>> 
>> PG 9.5 and up will flatten out cases like this to be exactly what you
>> wrote out longhand.

> ​Does it matter if the values expression is embedded in a CTE?

Yes, CTEs are optimization fences ...
        regards, tom lane


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