Horton

Re: [HACKERS] pow support for pgbench

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Raúl Marín Rodríguez <rmrodriguez@carto.com>
Cc: Fabien COELHO <coelho@cri.ensmp.fr>, Tom Lane <tgl@sss.pgh.pa.us>, Michael Paquier <michael.paquier@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2017-12-05T19:48:32Z
Lists: pgsql-hackers 
On Tue, Dec 5, 2017 at 7:44 AM, Raúl Marín Rodríguez
<rmrodriguez@carto.com> wrote:
> I've been giving a thought about this and I think we could reach the
> compromise
> of having a single function with 2 overloads:
> * pow(double, double) -> double: Uses C pow().
> * pow(int, int) -> double: Uses ipow() for positive exponents, and pow()
> for negative exponents.
>
> In both cases we'd return a double but we use the fast ipow if it's possible
> (which can be 20x faster), so at the cost of an extra cast if you need an
> int,
> we'd have a consistent API. Would this be acceptable?

It seems OK to me.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Add pow(), aka power(), function to pgbench.

  2. pgbench: Support double constants and functions.