| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Luis Vargas <Luis(dot)Vargas(at)cl(dot)cam(dot)ac(dot)uk> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Execution Plan Cost |
| Date: | 2008-05-08 17:19:36 |
| Message-ID: | 4197.1210267176@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Luis Vargas <Luis(dot)Vargas(at)cl(dot)cam(dot)ac(dot)uk> writes:
> At the backend, I'm measuring the cost of executing (via SPI_execute_plan)
> the read-only plan of a simple query with no reference to tables. E.g.
> simpleplan(int) AS SELECT $1 > 5
> Executing this plan via SPI_execute takes around 70% more time than
> directly executing the relevant operator function (int4gt) and using
> DatumGetBool.
Only that much? I'd have expected it to be several hundred times
slower, considering that int4gt is an utterly trivial function and
executor startup/shutdown is a fairly heavyweight operation.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Josh Berkus | 2008-05-08 17:33:26 | Re: Auto-updated fields |
| Previous Message | Luis Vargas | 2008-05-08 17:11:58 | Execution Plan Cost |