Re: [HACKERS] CTE inlining

Yeah, the idea that this won't cause possibly significant pain is quite wrong. Quite by accident I came across an example just this morning where rewriting as a CTE makes a big improvement.

I wrote this query:

    select (json_populate_record(null::mytype, myjson)).*
    from mytable;


It turned out that this was an order of magnitude faster:

    with r as
    (
       select json_populate_record(null::mytype, myjson) as x
       from mytable
    )
    select (x).*
    from r;